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+ OS/8 FORTRAN IV
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+ SOFTWARE SUPPORT MANUAL
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+
+
+
+
+
+ DISCLAIMER
+
+ This document file was created by scanning the
+ original document and then editing the scanned
+ text. As much as possible, the original text
+ format was restored. Some format changes were
+ made to insure this document would print on
+ current laser printers using 60 lines per page,
+ which changed the page numbering. The original
+ spelling and grammar have been preserved.
+
+
+ 1-NOV-1997
+\f
+
+ DEC-S8-LFSSA-A-D
+
+ AA-4532A-TA 056573
+
+
+
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+ OS/8 FORTRAN IV
+
+ SOFTWARE SUPPORT MANUAL
+
+
+
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+
+ ----------------------------------------------------------
+ | For additional copies, order No. DEC-S8-LFSSA-A-D |
+ | from Software Distribution Center, Digital Equipment |
+ | Corporation, Maynard, Mass. |
+ ----------------------------------------------------------
+
+
+ digital equipment corporation - maynard, massachusetts
+\f
+
+
+ First Printing
+ June, 1973
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Copyright (c) 1973 by Digital Equipment Corporation
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ The following are trademarks of Digital Equipment Corporation,
+ Maynard, Massachusetts:
+
+ CDP DIGITAL KA10 PS/8
+ COMPUTER LAB DNC LAB-8 QUICKPOINT
+ COMTEX EDGRIN LAB-8/e RAD-8
+ COMSYST EDUSYSTEM LAB-K RSTS
+ DDT FLIP CHIP OMNIBUS RSX
+ DEC FOCAL OS/8 RTM
+ DECCOMM GLC-8 PDP SABR
+ DECTAPE IDAC PHA TYPESET 8
+ DIBOL IDACS UNIBUS
+ INDAC
+
+
+
+
+
+
+
+
+
+ ii
+\f
+
+
+ CONTENTS
+
+
+
+
+ CHAPTER 1 THE F4 COMPILER 1-1
+
+ CHAPTER 2 THE RALF ASSEMBLER 2-1
+
+ CHAPTER 3 THE FORTRAN IV LOADER 3-1
+
+ CHAPTER 4 THE FORTRAN IV RUN-TIME SYSTEM 4-1
+
+ CHAPTER 5 LIBRA AND FORLIB 5-1
+
+ APPENDIX A RALF Assembler Permanent Symbol Table A-1
+
+ APPENDIX B Assembly Instructions B-1
+
+
+
+
+
+
+
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+
+
+
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+
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+
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+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ iii
+\f
+
+
+ CHAPTER 1
+
+ THE F4 COMPILER
+
+
+ The OS/8 F4 compiler runs in 8K on either a PDP-8 or a PDP-12. It
+ operates in three passes to transform FORTRAN IV source programs into
+ RALF assembly language. The function of each of the three passes is:
+
+ 1. Analyze statements, check syntax and convert to a polish
+ notation.
+
+ 2. Convert output of PASS1 to RALF assembly language making
+ extensive use of code skeleton tables.
+
+ 3. Produce a listing of the FORTRAN source program and/or chain
+ to the assembler.
+
+ The following is a more complete description of each of the three
+ passes.
+
+
+
+ PASS1 OPERATION
+
+ After opening the source language input file(s) and an intermediate
+ output file, PASS1 processes statements in the following fashion:
+
+ 1. Assemble a statement into the statement buffer by reading
+ characters from the OS/8 input file. This section eliminates
+ comments and handles continuations so that the statement
+ buffer contains the entire statement as if it had been
+ written on one long line.
+
+ 2. The statement is first assumed to be an arithmetic assignment
+ and an attempt is made to compile it as such. This is done
+ with a special switch (NOCODE) set so that in the event the
+ statement is not arithmetic, no erroneous output is produced.
+ Thus, with this switch set, the expression analyzer
+ subroutine is used merely as a syntax checker.
+
+ 3. If the statement is indeed an arithmetic assignment statement
+ (or arithmetic statement function) the switch is set off and
+ the statement is then recompiled, this time producing output.
+
+ 4. If not an arithmetic assignment, the statement might be one
+ of the keyword defined statements. The compiler now checks
+ the first symbol on the line to see of it is a legal keyword
+ (REAL, GOTO, etc.) and jumps to the appropriate subroutine if
+ so. Any statement that is not now classified is considered
+ to be in error.
+
+ 5. The compilation of each statement takes place. Some state-
+ ments produce only symbol table entries (e.g., DIMENSION)
+
+ 1-1
+\f
+
+
+ which will be processed by PASS2. Others use the arithmetic
+ expression analyzer (EXPR) and also output special purpose
+ operators which will tell PASS2 what to do with the value
+ represented by the arithmetic expression (e.g., IF, DO).
+
+ 6. After the statement has been processed, control passes to the
+ end-of-statement routine which handles DO-loop terminations
+ and then outputs the end-of-statement code.
+
+ 7. Statements containing some kind of error cause a special
+ error code to be output.
+
+ 8. The entire process is now repeated for the next statement.
+
+ 9. When the END statement is encountered, PASS1 chains to PASS2.
+
+
+
+ PASS1 SYMBOL TABLE
+
+ A significant portion of the PASS1 processing involves the production
+ of symbol table entries. These entries contain all storage related
+ information, i.e., variable name, type, dimensions, etc.
+
+ The symbol table is organized as a set of linked lists. The first 26
+ such lists are for variables, with the first letter of the variable
+ name corresponding to the ordinal number of the list. There are also
+ separate lists for statement numbers and literals (integer, real,
+ complex, double, and Hollerith). In addition to list elements, there
+ are special entries for holding DIMENSION and EQUIVALENCE information.
+
+ A detailed description of each type of entry follows. (NOTE: All
+ symbol table entries are in Field 1.)
+
+ 1. VARIABLE - The first word of each entry is a pointer to the
+ next entry, with a zero pointer signaling end of list. The
+ second word contains type information. The third word points
+ to the dimension and/or equivalence information blocks. The
+ next one to three words contain the remainder of the name
+ (the first character is implied by which list the entry is
+ in) in stripped six-bit ASCII terminated by a zero character.
+ Thus, shorter variables take less symbol table space. The
+ entries are (as for all lists in the symbol table) arranged
+ in order of increasing magnitude, or alphabetically.
+
+
+
+
+
+
+
+
+
+
+
+ 1-2
+\f
+
+
+ ---------------
+ POINTER | ------> |
+ |-------------|
+ TYPE | | | | | | | |
+ |-------------|
+ DIMENSION/EQUIVALENCE | ------> |
+ |-------------|
+ NAME 2-3 | N | A |
+ |-------------|
+ NAME 4-5 | M | E |
+ |-------------|
+ NAME 6 | X | 0 |
+ ---------------
+
+
+ TYPE WORD FORMAT
+
+ 0 1 2 3 4 5 6 7 8 9 10 11
+ ----------------------------------------------------------------------
+ | C | D | E | A | E | E || L | A | T || Y | P | E |
+ | O | I | X | S | Q | X || I | R | || | | |
+ | M | M | T | F | U | P || T | G | || | | |
+ | | | | | I | L || | | || | | |
+ | | | | | V | I || | | || | | |
+ | | | | | | C || | | || | | |
+ ----------------------------------------------------------------------
+
+ BIT
+
+ 0 - Variable is in common.
+ 1 - Variable is dimensioned.
+ 2 - External symbol or subroutine/function name.
+ 3 - Symbol is the name of an arithmetic statement function.
+ 4 - Variable is an equivalence slave.
+ 5 - Variable is explicitly typed.
+ 6 - Entry is a literal.
+ 7 - Variable is a formal parameter.
+
+ - 1 integer
+ | 2 real
+ | 3 complex
+ 8-11 < 4 double
+ Type | 5 logical
+ | 8 statement number
+ - 9 common section name
+
+ 2. STATEMENT NUMBER - The first two words are the standard
+ pointer/type. The next three words are the statement number,
+ with leading zeros deleted, in stripped six-bit ASCII, filled
+ to the right with blanks.
+
+
+
+
+
+ 1-3
+\f
+
+ ---------------
+ POINTER | ------> |
+ |-------------|
+ TYPE | | | | | | | |
+ |-------------|
+ NUMBER 1-2 | N | U |
+ |-------------|
+ NUMBER 3-4 | M | B |
+ |-------------|
+ NUMBER 5 | R | |
+ ---------------
+
+ 3. INTEGER OR REAL LITERALS - The first two words are the
+ pointer and type. The next three words are the value in
+ standard floating-point format (12-bit exponent, 24-bit
+ signed 2's complement mantissa). Since the type of the
+ literal must be preserved, there are two lists; hence use of
+ 1 and 1.0 in the same program will cause one entry in each of
+ the integer and real literal lists.
+
+ ---------------
+ POINTER | ------> |
+ |-------------|
+ TYPE | | | | | | | |
+ |-------------|
+ EXPONENT | V |
+ |----A--------|
+ MANTISSA 0-11 | L |
+ |--------U----|
+ MANTISSA 12-23 | E |
+ ---------------
+
+ 4. COMPLEX LITERALS - The first two words are standard. The
+ next three are the real part in standard floating-point
+ format. The next three are the imaginary part.
+
+ ---------------
+ POINTER | ------> |
+ |-------------|
+ TYPE | | | | | | | |
+ |-------------|
+ REAL EXPONENT | R |
+ |----E--------|
+ REAL MANTISSA 0-11 | A |
+ |------L------|
+ REAL MANTISSA 12-23 | |
+ |-------------|
+ IMAGINARY EXPONENT | IM |
+ |----A--------|
+ IMAGINARY MANTISSA 0-11 | GIN |
+ |--------A----|
+ IMAGINARY MANTISSA 12-23 | RY |
+ ---------------
+
+
+
+ 1-4
+\f
+
+
+ 5. DOUBLE PRECISION LITERALS - The first two words are standard.
+ The next six are the literal in FPP extended format (12-bit
+ exponent, 60-bit mantissa).
+
+ ---------------
+ POINTER | ------> |
+ |-------------|
+ TYPE | | | | | | | |
+ |-------------|
+ EXPONENT | |
+ |-------------|
+ MANTISSA 0-11 | |
+ |-------------|
+ MANTISSA 12-23 | |
+ |-------------|
+ MANTISSA 24-35 | |
+ |-------------|
+ MANTISSA 36-47 | |
+ |-------------|
+ MANTISSA 48-59 | |
+ ---------------
+
+ 6. HOLLERITH (quoted) LITERALS - The first two words are stan-
+ dard. The next N words are the characters of the literal in
+ stripped six-bit ASCII, ending in a zero character.
+
+ ---------------
+ POINTER | ------> |
+ |-------------|
+ TYPE | | | | | | | |
+ |-------------|
+ CHARACTERS 1-2 | |
+ ---------------
+ etc. .............
+
+
+ 7. DIMENSION INFORMATION BLOCK - If a variable is DIMENSIONed,
+ the third word of its symbol table entry will point to its
+ dimension information block (may be indirectly, see section
+ 8 below). The first word of this block is the number of
+ dimensions. The second word is the total size of the array
+ in elements; thus the size in PDP-8 words may be 3 or 6 times
+ this number. The third word contains the "magic number"
+ which is computed as follows:
+
+ n-1 i
+ MN= - 1+ SUM of d(j)
+ i=1 j=1
+
+ where d(j) is the jth dimension and n is the number of
+ dimensions.
+
+
+
+
+ 1-5
+\f
+
+
+ For a 3-dimensional variable this number becomes:
+
+ MN+ 1+d(1)+d(1)d(2)
+
+ The magic number must be subtracted from any computed index,
+ since indexing starts at one and not zero. The fourth word
+ will (in PASS2) contain the displacement from #LIT of a
+ literal which will contain either the magic number in
+ un-normalized form (for dimensioned variables which are
+ subroutine arguments) or the address of the variable minus
+ the magic number (for local or COMMON dimensioned variables).
+ This literal is necessary for calling subroutines where a
+ subscripted variable is an argument. The next N words are
+ the dimensions of the variable. If the variable is a formal
+ parameter of the subroutine, it may have one or more dimen-
+ sions which are also formal parameters. In this case, the
+ magic number is zero, and the dimension(s) is a pointer to
+ the symbol table entry for the variable(s) used as a dimen-
+ sion.
+
+ ----------
+ NUMBER OF DIMENSIONS | # |
+ |--------|
+ TOTAL NUMBER OF ELEMENTS | SIZE |
+ |--------|
+ MAGIC NUMBER | MN |
+ |--------|
+ RESERVED | |
+ |--------|
+ DIMENSION 1 | D1 |
+ |--------|
+ DIMENSION 2 | D2 |
+ ----------
+ ........
+ ----------
+ DIMENSION n | Dn |
+ ----------
+
+ 8. EQUIVALENCE INFORMATION BLOCK - If a variable is an
+ EQUIVALENCE slave variable, the third word of its symbol
+ table entry points to the equivalence information block.
+ The first word of this block points to the dimension infor-
+ mation (if any) of the variable. The second word points to
+ the symbol table entry of the EQUIVALENCE master variable.
+ The third word is the linearized subscript of the master
+ variable from the EQUIVALENCE statement. The fourth word is
+ the linearized subscript of the slave variable.
+
+
+
+
+
+
+
+
+ 1-6
+\f
+
+
+ ---------------
+ POINTER TO DIMENSIONS | ------> |
+ |-------------|
+ POINTER TO MASTER | ------> |
+ |-------------|
+ MASTER SUBSCRIPT | SSM |
+ |-------------|
+ SLAVE SUBSCRIPT | SSM |
+ ---------------
+
+ 9. COMMON INFORMATION BLOCK - If a symbol is defined as the name
+ of a COMMON section, the third word of its symbol table entry
+ points to a list of common information blocks. The first
+ word of each such block points to the next block. The second
+ word is the number of entries in the list that follows. The
+ rest of the block is a set of pointers to the symbol table
+ entries of the variables in the COMMON section.
+
+ ---------------
+ POINTER TO NEXT CIB | ------> |
+ |-------------|
+ NUMBER OF ENTRIES | # |
+ |-------------|
+ - | ------> |
+ | |-------------|
+ POINTER TO VARIABLES < | ------> |
+ IN THIS COMMON | |-------------|
+ - | ------> |
+ ---------------
+
+
+
+ PASS1 OUTPUT
+
+ The output of PASS1 is a stream of polish with many special operators.
+ Whenever an operand is to be output, the address of its symbol table
+ entry is used. The following is a list of the output codes (in their
+ mnemonic form, obtain numeric values from listing of PASS1) and the
+ operation they are conveying to PASS2:
+
+ PUSH The next word in the output file is an operand
+ (symbol table pointer) to be put onto the stack.
+
+ ADD Add the operands represented by the top two stack
+ entries (actually this causes PASS2 to generate
+ the RALF coding which will do the desired add).
+
+ SUB Subtract top from next-to-top.
+
+ MUL Multiply top two.
+
+ DIV Divide top into next-to-top.
+
+ EXP Raise next-to-top to power of top.
+
+ 1-7
+\f
+
+
+ NOT Logical .NOT. of top of stack.
+
+ NEG Negate top of stack.
+
+ GE Compare top two for greater than or equal to, this
+ has TRUE value if the next-to-top is .GE. the top.
+
+ GT Compare for greater than.
+
+ LE Compare for less than or equal.
+
+ LT Compare for less than.
+
+ AND Logical AND of top two entries.
+
+ OR Logical inclusive OR of top two.
+
+ EQ Compare top two for equality.
+
+ NE Compare top two for inequality.
+
+ XOR Exclusive OR of top two.
+
+ EQV EQUIVALENCE of top two.
+
+ PAUSOP Use top of stack as PAUSE number.
+
+ DPUSH The next two words are a symbol table pointer and
+ a displacement; put them onto the stack (used for
+ DATA statements).
+
+ BINRD1 Take the top of stack as the unit number and com-
+ pile an unformatted READ-open.
+
+ FMTRD1 The top two stack elements are the unit and
+ format, take them and compile a formatted READ-
+ open.
+
+ RCLOSE Compile a READ-close.
+
+ DARD1 Take the top two stack elements as a unit number
+ and a block number and compile a direct access
+ unformatted READ-open.
+ BINWR1 -
+ FMTWRI |> Same as for the corresponding READ case, except
+ WCLOSE | substitute the word "WRITE".
+ DAWR1 -
+
+ DEFFIL Take the top four stack entries as the unit,
+ number of records, record size, and index
+ variable and compile a DEFINE FILE call.
+
+ ASFDEF Set the PASS2 switch which says that the following
+ statement is an arithmetic statement function.
+
+ 1-8
+\f
+
+
+ ARGSOP The next word is a count, call it n; take the
+ previous n stack entries as subscripts (or
+ arguments) and the N+1st entry from the top as
+ the array (or function) name; now compile this
+ as an array reference (or function/subroutine
+ call).
+
+ EOLCOD The current statement is completed, reset stacks
+ and do other housekeeping.
+
+ ERRCOD The following word contains an error code, write
+ it on the TTY together with the current line
+ number, and put the error code and line number
+ into the error list for possible PASS3.
+
+ RETOPR Compile a subroutine RETURN.
+
+ REWOPR Take the top of stack as a unit and compile a
+ rewind.
+
+ STOROP Compile a store of the top of stack into the
+ next-to-top.
+
+ ENDOPR Compile a RETURN if a function or subroutine or
+ a CALL EXIT if a main program.
+
+ DEFLBL The following word is a symbol table pointer to
+ a statement number, compile this as the tag for
+ the current RALF line.
+
+ DOFINI The following word is a symbol table pointer for
+ the DO-loop index, compile the corresponding
+ DO-ending code.
+
+ ARTHIF The following one, two, or three words are symbol
+ table pointers to statement numbers for the less
+ than zero, zero, and greater than zero conditions
+ with the comparison to be made on the top of
+ stack.
+
+ LIFBGN The top of stack is taken as a logical expression
+ PASS 2 should compile a jump-around-on-false; this
+ implies that some statement is to follow.
+
+ DOBEGN The top two stack entries represent the final
+ value and increment of the DO-loop, process them
+ in hopes of finding a matching DOFINI.
+
+ ENDFOP The top of stack is a unit, compile an END FILE.
+
+ STOPOP Compile a CALL EXIT.
+
+
+
+
+ 1-9
+\f
+
+
+ ASNOPR The next word is the address of the symbol table
+ entry for a statement number; compile an ASSIGN
+ of this statement number to the variable
+ represented by the top of stack.
+
+ BAKOPR Take the top of stack as the unit and compile
+ a BACKSPACE.
+
+ FMTOPR The following word is a count N; the next N words
+ after that are the image of the FORMAT statement.
+
+ GO2OPR The following word is the symbol table entry for
+ the statement number which is to be executed next.
+
+ CGO2OP The following word is a count N; the next N words
+ are symbol table pointers for the statement
+ numbers of a computed GO TO list; use the value
+ represented by the top of stack to compile a
+ computed GO TO into this list.
+
+ AGO2OP Compile an assigned GO TO with the top of stack.
+
+ IOLMNT Take the top of stack as a list element for an
+ I/O statement and compile read or write; PASS2
+ knows if it is a READ or WRITE by remembering
+ previous FMTRD1, FMTWR1, etc.
+
+ DATELM The next word is a count N; the next N words are
+ a data element.
+
+ DREPTC The next word is a repetition count for the set
+ of DATELMs up until the next ENDELM.
+
+ ENDELM Signals the end of a data element group.
+
+ PRGSTK Tells PASS2 to purge the top stack entry.
+
+ DOSTOR Performs the same function as STOROP after
+ checking the top two stack elements for legal
+ DO-parameter type (integer or real).
+
+
+
+ PASS 1 SUBROUTINES
+
+ The following is a brief description of the function of each of the
+ major PASS1 subroutines:
+
+ RDWR Compiles everything in a READ or WRITE statement
+ starting at the first left parenthesis.
+
+ RESTCP Restore character pointer and count for the
+ statement buffer from the stack.
+
+
+ 1-10
+\f
+
+
+ OUTWRD Output a word (the AC on entering) to the PASS1
+ output file.
+
+ COMARP Test for comma or right parenthesis, skip one
+ instruction if a comma, two if a right
+ parenthesis, and none if neither.
+
+ BACK1 Backup the statement buffer character pointer.
+
+ GETSS Scans a variable reference, or subscripted
+ variable reference with numeric subscripts and
+ returns the linearized subscript.
+
+ MUL12 Perform a 12-bit unsigned integer multiply.
+
+ DOSTUF Handles compilation of DO-loop setup.
+
+ TYPLST Process a type declaration, DIMENSION, or
+ COMMON statement; sets up type bits and/or
+ dimension information.
+
+ LOOKUP Perform a symbol table search for variables and
+ Hollerith literals.
+
+ LUKUP2 Perform a symbol table search for integer, real,
+ complex, and double precision literals or
+ statement numbers.
+
+ EXPR Analyze and process an arithmetic expression.
+
+ LETTER Get next character from the statement buffer and
+ skip if it is a letter, otherwise put the
+ character back and don't skip.
+
+ CHECKC The first word after the JMS is the negative of
+ the ASCII character to test for; if this is the
+ next character, skip.
+
+ GETCWB Get the next character from the statement buffer
+ preserving blanks.
+
+ SAVECP Save the character pointer and count on the stack.
+
+ GETC Get the next character ignoring blanks.
+
+ ERMSG Output an error code to PASS1 output file.
+
+ POP Pop the stack into the AC.
+
+ PUSH Push the AC onto the stack.
+
+ LEXPR Analyze and process an arithmetic expression,
+ legal to the left of the equal sign in an
+ assignment statement.
+
+ 1-11
+\f
+
+ GET2C Get the next two character into one word.
+
+ STMNUM Scan off a statement number and do the symbol
+ table search.
+
+ DIGIT Same as letter, except checks for a digit.
+
+ NUMBER Scans off an integer, real, or double precision
+ literal.
+
+ GETNAM Scan off a variable name.
+
+ ICHAR Get the next character from the input file.
+
+
+
+ PASS2 OPERATION
+
+ The first part of PASS2 generates the storage for variables,
+ arguments, arrays, literals and temporaries by processing the symbol
+ table built by PASS1, which is kept in core. The next step is to
+ generate the code for subroutine entry and exit including argument
+ pickup and restore. After all such prolog code is generated, PASS2O
+ is loaded into core, overlaying most of the prolog-generating
+ functions. The main loop of the compiler is now entered. This
+ consists simply of reading a PASS1 output code from the intermediate
+ file and using this number as an index into a jump table. The
+ sections of code entered in this way then perform the correct
+ generation of RALF code.
+
+ Example:
+
+ The statement: A=B+C*D
+ would produce the following PASS1 output:
+ (assuming A,B,C,D are REAL)
+
+ 1) PUSH
+ ->A (symbol table address of A)
+
+ 2) PUSH
+ ->B
+
+ 3) PUSH
+ ->C
+
+ 4) PUSH
+ ->D
+
+ 5) MUL
+
+ 6) ADD
+
+ 7) STOROP
+
+ 8) EOLCOD
+
+ 1-12
+\f
+
+
+ The corresponding operations performed by PASS2 are:
+
+ 1) Make a 3-word entry on the stack corresponding to the
+ variable A consisting of a pointer to the symbol table
+ entry, a word containing the type, and one reserved word.
+
+ 2) Repeat above for B.
+
+ 3) Repeat above for C.
+
+ 4) Repeat above for D.
+
+ 5) The multiply operator is handled like any of the binary
+ operators by the subroutine CODE. This routine is called
+ with the address of the multiply skeleton table. The
+ top two stack entries are taken as the operands, with
+ their types used to index into the skeleton tables.
+ (See description of binary operator skeleton tables below.)
+ The correct skeleton for this combination is chosen based on
+ the where-abouts of each of the operands (AC or memory)
+ at the corresponding point in the code which is being
+ compiled. There are three possible cases: Memory,AC;
+ Memory,Memory; AC,Memory. In this example, both operands
+ are in memory so the code generated would be:
+
+ FLDA C
+
+ FMUL D
+
+ The CODE subroutine then makes a new stack entry to replace
+ the entries for C and D. This entry has a 0 in place of
+ the symbol table pointer, signifying that the operand is in
+ the AC. Other special case operand codes are:
+
+ 0 - AC ( Already mentioned)
+
+ 1 - 51 Temporaries
+
+ 52 - 60 Array reference, the subscript of which is in
+ an index register (1-7).
+
+ 61 - A variable, the address of which is in base
+ location 0.
+
+ 62 - A variable, the address of which is in base
+ location 3.
+
+ 63-6777 - Symbol table entry (can be variable or
+ literal).
+
+ 7000 - Special temporary
+
+
+
+
+ 1-13
+\f
+
+
+ 6) The add operator is handled in the same way as for multiply,
+ except that in this case the add skeleton table is used.
+ When the correct row is found, the memory,AC case is chosen
+ since the result of C*D is now in the AC. This skeleton
+ simply generates:
+
+ FADD B
+
+ The new top of stack entry is a 0, since the result is in
+ the AC.
+
+ 7) The store operation works in a similar manner using a special
+ skeleton table to determine whether the value to be stored is
+ already in the AC and whether it must be converted from one
+ type to another. In this case, no conversion need be
+ performed and the code generated is:
+
+ FSTA A
+
+ 8) The end of statement has been reached and any necessary
+ bookkeeping is performed.
+
+
+
+ PASS2 SYMBOL TABLE
+
+ PASS2 modifies the symbol table entries corresponding to variables
+ by replacing the first word of the entry with the first character of
+ the name, this character being derived from the list in which the name
+ is located.
+
+
+
+ PASS2 ERROR LIST
+
+ PASS2 creates a list (in field 1) of error codes and line numbers
+ corresponding to the errors printed on the Teletype during PASS2.
+ This list works downward starting just below the skeleton table area,
+ working towards the symbol table area. PASS3 uses this list to
+ write out extended error messages on the listing.
+
+
+
+ PASS2 SKELETON TABLES
+
+ All binary operators have associated with them a skeleton table
+ having 24 entries arranged in 8 rows and 3 columns. The rows
+ correspond to the following eight possibilities:
+
+ 1) Both operands integer or real.
+ 2) Both operands complex.
+ 3) Both operands double precision.
+ 4) First operand integer or real, second complex.
+ 5) First operand integer or real, second double precision.
+
+ 1-14
+\f
+
+
+ 6) First operand complex, second integer or real.
+ 7) First operand double precision, second integer or real.
+ 8) Both operands logical.
+
+ The columns correspond to the following three possibilities:
+
+ 1) First operand in memory, second in AC.
+ 2) Both operands in memory.
+ 3) First operand in the AC, second in memory.
+
+ Each entry of the skeleton tables is either zero (illegal operator-
+ type combination) or points to a code skeleton (minus one). Code
+ skeletons are composed of combinations of the following types of
+ elements:
+
+ 1) OPCODES - If an element has a non-negative value, it is taken
+ as the address of a text string for the desired opcode. This
+ works since all such text strings are stored below location
+ 4000 (in field 0). In this case, the next word of the
+ skeleton is taken as a designator for the address field, the
+ possibilities are:
+
+ a. A non-negative values means the address field is a
+ literal text string, with the value being the address of
+ the string. (Same restriction as for opcode text
+ strings.)
+
+ b. A zero indicates that this instruction should have no
+ address field.
+
+ c. A minus one indicates that the address field is the
+ operand defined by the three variables ARG1, TYPE1, and
+ BASE1.
+
+ d. A minus two indicates that the address field is the
+ operand defined by the three variables ARG2, TYPE2, and
+ BASE2.
+
+ 2) MODE CHANGE - An element value of minus one means generate a
+ STARTF if currently in extended mode. A value of minus two
+ means generate a STARTE if currently in single mode.
+
+ 3) MACRO - Any other negative value is taken as the address
+ (minus 3) of a sub-skeleton. This sub-skeleton may contain
+ anything except another sub-skeleton reference. When the
+ end of the sub-skeleton is encountered, the main skeleton is
+ re-entered.
+
+ 4) END-OF-SKELETON - A zero indicates the end of the skeleton.
+
+
+
+
+
+
+ 1-15
+\f
+
+
+ PASS2 SUBROUTINES
+
+ The following is a list of the major PASS 2 subroutines together with
+ a brief functional description.
+
+ ERMSG Output a 2-character error code together with the
+ line number on the Teletypes; also put the code and
+ line number into the error list for PASS3.
+
+ UCODE Generate the code for unary operators, given the
+ skeleton table address.
+
+ CODE Generate code for binary operators, given the
+ skeleton table address.
+
+ INWORD Read a word from the PASS1 output file.
+
+ FATAL Output a fatal error message and exit to OS/8.
+
+ ONUMBER Output the AC as a 4-digit octal number.
+
+ SAVEAC Generate an FSTA #TMP+XXXX if necessary.
+
+ GENCOD Generate the code specified by the given code
+ skeleton.
+
+ OPCOD Output a TAB followed by the specified opcode
+ field.
+
+ OPCODE Same as OPCOD, except output a second TAB after
+ the opcode field.
+
+ OADDR Generate the address field specified by the
+ argument.
+
+ GENSTF Generate STARTF if in E mode.
+
+ GENSTE Generate STARTE if in F mode.
+
+ OSNUM Output a statement number preceded by a "#".
+
+ CRLF Output a carriage return/line feed.
+
+ OTAB Output a TAB.
+
+ OUTSYM Output a text string.
+
+ GARG Pop the top entry of the stack into ARG1, TYPE1,
+ and BASE1.
+
+ GARGS Pop the top two stack entries into ARG1, TYPE1,
+ BASE1 and ARG2, TYPE2, BASE2.
+
+ OUTNAM Output a variable name.
+
+ 1-16
+\f
+
+
+ OLABEL Output a generated label.
+
+ GETSS Find the address of the dimension information
+ block given the symbol table address.
+
+ SKPIRL Skip if integer, real, or logical.
+
+ GENCAL Generate the code for a subroutine call from
+ the information contained on the stack.
+
+ MUL12 Do a 12-bit unsigned multiply.
+
+ OINS Output a literal opcode and address field.
+
+ OCHAR Output a character
+
+ NUMBRO Output a 5-digit octal number.
+
+
+
+ PASS3 OPERATION
+
+ PASS3 first initializes the listing header line with the version
+ number, date, and page number. It then processes lines, much like
+ PASS1, handling continuations and comments and outputs their image
+ to the listing file together with the line number. A constant check
+ is made on the error message list for line numbers that correspond
+ to the current line number, When such a correspondence occurs, the
+ error code is used to find the associated detailed error message,
+ which is then printed out.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ 1-17
+\f
+
+
+ CHAPTER 2
+
+ THE RALF ASSEMBLER
+
+
+ RALF and FLAP are essentially the same program, with differences con-
+ trolled by the conditional assembly parameter RALF, which must be
+ nonzero to assemble RALF, or zero to assemble FLAP. The source may be
+ assembled by either PAL8 or FLAP; although FLAP flags one error (a US
+ on a FIELD statement), this may safely be ignored. The remainder of
+ this chapter applies to RALF only. The following definitions are pre-
+ requisite to discussion of the operation of this assembler.
+
+ MODULE The relocatable binary output of an assembly. A module
+ is physically an OS/8 file or sub-file in a library,
+ and is made up of an external symbol dictionary and
+ related text. Logically, it consists of one or more
+ program sections and COMMON sections.
+
+ LIBRARY An OS/8 file on a directory device containing a catalog
+ and one or more modules as sub-files. Used solely by
+ the loader, as a source of modules with which to
+ satisfy unresolved symbols in a program being loaded.
+
+ CATALOG A list of entry points defined in modules contained in
+ a library, with an indication of the locations of the
+ modules which define them.
+
+ EXTERNAL A list of the global symbols defined in and/or used by
+ SYMBOL a module. Usually called ESD table.
+ DICTIONARY
+
+ TEXT That part of the assembler's binary output which
+ contains the binary data to be loaded into memory,
+ along with sufficient information for the loader to
+ associate the output with specific memory locations
+ through references to the ESD table.
+
+ SECTION A unit of binary data output by the assembler as part
+ of a module to be loaded into a contiguous area of
+ memory. COMMON sections are a special case in that
+ they may be defined with the same name in each of many
+ modules. In this case, all the definitions are combined
+ to create a single section in memory whose size is that
+ of the largest COMMON section with the given name.
+ Program sections, the only other type of section, must
+ have unique names. Sections are listed in the ESD
+ table by name, type and size.
+
+ ENTRY POINT An address within a section which is named and defined
+ to be global, so that it may be used for the resolution
+ of external references in other sections. Entry points
+ are listed in the ESD table by name, type and address
+ within the section in which they occur.
+
+ 2-1
+\f
+
+
+ EXTERNAL A symbol which is specified at assembly time to be
+ SYMBOL defined in another module as an entry point. External
+ symbols are listed in the ESD table by name and type.
+ A complete program must include entry point names
+ equivalent to every external symbol defined in every
+ module in the program. There need not, however, be an
+ external symbol for every entry point, nor is there any
+ limit on the number of modules which may contain
+ external symbols referencing one entry point. From a
+ functional viewpoint, entry points correspond to tags
+ within a program and external symbols correspond to
+ references to those tags. Every section is considered
+ to have an entry point at location zero of the section.
+ The name of this entry point is the section name.
+
+ When RALF is called from the monitor, execution begins at the tag
+ BEGIN. Unless entry is via CHAIN, the OS/8 command decoder is called
+ to obtain input and output file designations. If entry is by way of
+ CHAIN, it is assumed that the command decoder area has already been
+ set up by the caller. In either case, it is always assumed that the
+ USR is already in core. A check is made to determine that the first
+ output file is a directory device file and, if no first output file
+ was specified, the default file SYS:FORTRN.RL is set up.
+
+ Default output file extensions are defined if none were specified to
+ the command decoder, using .RL for the first output file and .LS for
+ the second output file. The first output file is then opened, and the
+ handler for the first input file is FETCHed. If /L or /G was
+ specified, the loader is looked up on SYS so that chaining will be
+ possible. The symbol table, which is loaded above 12000 in order to
+ preserve the USR, is now moved down to 10000. Finally, the system
+ date word is converted to character form and stored in the title
+ buffer. This completes the initialization procedure, and control is
+ passed to NEWLIN to collect the first line in the buffer.
+
+ At NEXTST, teats are made to determine whether the line just assembled
+ needs to be listed, and whether there are any remaining significant
+ characters in the line which have not been assembled. If a semicolon
+ terminated the statement, the character pointers are bumped to skip
+ over it, and control passes to ASMBL to process the next statement on
+ the line. If the assembler is currently in a REPEAT line and the
+ count is not exhausted, the current line is re-assembled. Otherwise,
+ a new line is obtained in the line buffer by collecting input
+ characters until a carriage return is found. If the line is longer
+ than 128 characters, all characters after the 128th are ignored and
+ the LT message is printed. The line length is calculated and saved.
+
+ At ASMBL, ASMOF is tested to determine whether the assembly is
+ currently inside a conditional. If so, the line is scanned for angle
+ brackets but not assembled. If not, and the first character is not a
+ slash, leading blanks are thrown away and control passes to LUNAME.
+ If there is a name, it is collected. If it is followed by a comma,
+ the symbol is looked up in the user symbol table. If the symbol is
+ undefined, it is defined as a label. If it was already defined, the
+
+ 2-2
+\f
+
+
+ current location counter is compared with it to check for a possible
+ MD error. Control then returns to ASMBL.
+
+ If the symbol found by LUNAME was followed by an equal sign, it is
+ looked up and defined according to the expression to the right of the
+ equal sign. If it was followed by a space, either of the characters
+ ' or #, or the character % and then a space, it is looked up in the
+ op-code table. If it is found, control passes to the appropriate
+ op-code handler. Otherwise, control is dispatched to GETEXP which
+ restores the character pointers saved by LUNAME, processes the rest of
+ the line as a single-word expression, and returns to NEXTST for the
+ next statement.
+
+ Expressions are processed on a strict left-to-right basis by the
+ routine EXPR. A symbol is looked up, and its value is stored in WORD1
+ and WORD2. It is then combined with the accumulated expressions in
+ EXPVAL according to the operator in LASTOP. A new operator (if any)
+ is then located, and the loop begins again. When no operator is found
+ after some symbol, the expression is considered complete and control
+ returns to the calling routine. Undefined symbols appearing in an
+ expression cause output of a US message, and the value zero is used
+ in their place. COMMON and section names in the symbol table have
+ special values (namely their lengths), but they always refer to the
+ starting location of the sections they define, and their values are
+ taken to be zero of the section so named. If GETNAM is not able to
+ find a symbol in the expression, three possibilities are checked
+ before flagging the expression as invalid:
+
+ 1. It may be a number, rather than a symbol.
+
+ 2. It may be one of the characters period (representing the
+ current value of the location counter) or double quote
+ (representing the binary value of the next ASCII character).
+
+ 3. The last operator may have been a plus sign in an indexed FPP
+ instruction.
+
+ At the end of expression evaluation, the console keyboard flag is
+ checked to ensure that the user has not typed CTRL/C to stop the
+ assembly.
+
+ There are six expression operator routines, one each for the
+ operations add, subtract, AND, OR, multiply and divide. Except for
+ add and subtract, these routines must operate on absolute addresses
+ because the loader does not have facilities for non-additive
+ resolution of address constants.
+
+ The symbol table is the sole occupant of field 1, except for the OS/8
+ field 1 resident. The symbol table is loaded at location 12000 to
+ prevent an unnecessary swap of the USR, but moved down, to start at
+ location 10000, during initialization. Subsequent calls to the USR do
+ require a swap. The symbol table is a set of linked lists, or, more
+ properly, two sets; one for user-defined symbols and one for op-codes
+ and pseudo-ops. Each set contains a list corresponding to every
+
+ 2-3
+\f
+
+
+ letter of the alphabet, and each list consists of the symbols which
+ start with that same letter. Every time a symbol is encountered in
+ the source, the list corresponding to its first letter is searched
+ until a match is found, or until the end of the list or a symbol of
+ higher alphabetical order is found. In the latter cases, the new
+ symbol is inserted into the user symbol table by changing the list
+ pointers so that the new symbol appears in the list in correct
+ alphabetical order. The pre-defined symbol table is never changed,
+ because the user is not permitted to define op-codes or pseudo-ops.
+
+ A RALF output file of relocatable binary data consists of two parts;
+ the ESD table and the text. The ESD table contains all information
+ required by LIBRA or the loader, and is generated between the first
+ and second passes of assembly. It serves as a partial symbol table
+ for the loader (the full symbol table is built up from the ESD tables
+ of all the modules in a program) and provides the name, attributes,
+ and value of every global symbol used by any module, as well as an ESD
+ code by which the symbol may be referred to within the text. Every
+ entry in the ESD table is six words long. The first three words are
+ the symbol itself, packed in stripped ASCII, with two characters per
+ word. The next word contains type information in the following
+ format:
+
+ A VALUE OF INDICATES
+
+ 0 Last entry in the ESD table.
+
+ 1 The symbol is defined as external to this module. The
+ value of the symbol must be resolved by a symbol of the
+ same name appearing in the ESD table of another module.
+ The ESD code which follows the type code is the code by
+ which references to this symbol will be identified in the
+ text.
+
+ 2 The symbol is defined as an entry point in this module.
+ It is therefore suitable for the resolution of external
+ references in other modules. The ESD code which follows
+ the type word identifies the program section in which
+ this entry point appears, and the value of the symbol is
+ relative to that section.
+
+ 3 The symbol is defined as a COMMON section whose size is
+ at least as large as specified by the value of the
+ symbol. If several modules contain ESD entries referring
+ to COMMON sections with the same name, a single COMMON
+ block having the size of the largest symbol is allocated
+ for all of them. A name consisting of blanks is treated
+ in the same manner as any other name.
+
+ 4 The symbol is defined as a section of location
+ independent (that is, fully word-relocatable) code of a
+ size equal to the value of the symbol. The ESD code for
+ this section allows text from the module to be included
+ in this section, and relocated with respect to it.
+
+ 2-4
+\f
+
+
+ 5-17 Undefined
+
+ The text portion of a relocatable binary file consists of the binary
+ data to be loaded into memory, along with information directing the
+ loader on how to modify that data to correct the addresses for program
+ relocation. The first word of text is a control word, which is made
+ up of a 4-bit type code and an 8-bit indicator. Following the control
+ word, and depending on the type code, are a number of data words to be
+ loaded as directed by the type code and the indicator. The control
+ word type codes are:
+
+ CODE FUNCTION
+
+ 0 End of text, if the indicator is zero, or no operation
+ otherwise.
+
+ 1 Copy the number of words given by the indicator from text
+ directly into memory without modification.
+
+ 2 Re-origin to the section identified by the indicator,
+ with a relative location defined by bits 9-23 of the
+ following doubleword. Thus, the next two words define a
+ new origin for the following text, in the program section
+ identified by the indicator.
+
+ 3 Relocate the following doubleword bits 9-23 by the value
+ of the symbol whose ESD code is identified by the
+ indicator. The following doubleword is usually a two-
+ word FPP instruction, the low-order 15 bits of which are
+ to be relocated by the value of the symbol identified by
+ the indicator.
+
+
+
+ WRITING PDP-8 CODE UNDER OS/8 FORTRAN IV
+
+
+ RALF contains the normal set of PDP-8 instructions (TAD, DCA, CDF,
+ KSF, etc.), however RALF does not allow literals, the PAGE pseudo-op,
+ or the use of I to specify indirect addressing. PDP-8 code generated
+ by RALF is not relocatable; therefore, operations such as the
+ following are illegal:
+
+ EXTERN SWAP /Illegal
+ TAD (SWAP /Under
+ CDF SWAP /RALF
+
+ The character % appended to the end of a memory reference instruction
+ indicates indirect addressing, and the character Z indicates a page 0
+ reference:
+
+
+
+
+
+ 2-5
+\f
+
+
+ CURRENT PAGE PAGE ZERO
+ DIRECT INDIRECT DIRECT INDIRECT
+
+ TAD A TAD% A TADZ A TADZ% A
+ DCA B DCA% B DCAZ B DCAZ% B
+
+ Spaces are not allowed between memory reference instructions and
+ either the Z or the % characters. The Z must precede the % when both
+ are used. I.e., do not write "DCA%Z".
+
+ Three pseudo-ops have been added to RALF: SECT8, COMMZ, and FIELD1.
+ All three define sections of code and are handled in the same manner
+ as SECT; however, these new sections have special meaning for the
+ loader. The address pseudo-op (ADDR) which generates a two word re-
+ locatable 15 bit address (i.e., JA TAG without use of JA) might prove
+ useful in 8-mode routines. The following example demonstrates a way
+ in which an 8-mode routine in one RALF module calls an 8-mode routine
+ in another module:
+
+ EXTERN SUB
+ .
+ .
+ RIF /Set DF to current
+ TAD ACDF /IF for return
+ DCA .+1
+ 0 /CDF X
+ TAD KSUB /Make a CIF from
+ RTL CLL /Field bits
+ RAL
+ TAD ACIF
+ DCA .+1
+ 0 /CIF to field
+ /Containing SUB
+ JMS% KSUB+1
+
+ KSUB, ADDR SUB /Psuedo-op to
+ /Generate 15 bit
+ /ADDR of subroutine
+ /SUB
+ ACDF, CDF
+ ACIF, CIF
+
+ In general the address pseudo-op can be used to supply an 8-mode
+ section with an argument or pointer external to the section.
+
+ FPP and 8-mode code may be intermixed in any RALF section. PDP-8 mode
+ routines must be called in FPP mode by either:
+
+ TRAP3 SUB
+
+ or TRAP4 SUB
+
+ A TRAP3 SUB causes FRTS to generate a JMP SUB with interrupts on and
+ the FPP hardware (if any) halted. TRAP4 generates a JMS SUB under the
+
+ 2-6
+\f
+
+
+ same conditions. The return from TRAP4 is:
+
+ CDF CIF 0
+ JMP% SUB
+
+ The return from TRAP3 is:
+
+ CDF CIF 0
+ JMP% RETURN+1
+ EXTERN #RETRN
+ RETURN, ADDR #RETRN
+
+
+ Communication between FPP and 8-mode routines is best done at the FPP
+ level because of greater flexibility in both addressing and relocation
+ in FPP mode. The following routine demonstrates how to pass an argu-
+ ment to, and retrieve an argument from, an 8-mode routine:
+
+ EXTERN SUB
+ EXTERN SUBIN
+ EXTERN SUBOUT
+ .
+ .
+ .
+ FLDA X /Arg for SUB
+ FSTA SUBIN
+ TRAP4 SUB /Call SUB
+ FLDA SUBOUT /Get result
+ FSTA Y
+
+ If the 8-mode routine SUB were in the same module as the FPP routine,
+ the externs would not be necessary. In practice it is common for FPP
+ and 8-mode routines that communicate with one another to be in the
+ same section. A number of techniques can be used to pass arguments.
+ For example, an FPP routine could move the index registers to an
+ 8-mode section and pass single precision arguments via ATX.
+
+ Because 8-mode routines are commonly used in conjunction with FPP code
+ (generated by the compiler), the 8-mode programmer should be familiar
+ with OS/8 FORTRAN IV subroutine calling conventions. The general code
+ for a subroutine call is a JSR, followed by a JA around a list of
+ arguments, followed by a list of pointers to the arguments. The FPP
+ code for the statement:
+
+ CALL SUB (X,Y,Z)
+
+ would be
+
+ EXTERN SUB
+ JSR SUB
+ JA BYARG
+ JA X
+ JA Y
+ JA Z
+
+ 2-7
+\f
+
+
+ BYARG, .
+ .
+ .
+ .
+
+ The general format of every subroutine obeys the following scheme:
+
+ SECT SUB
+ JA #ST /Jump to start of
+ /Routine
+ TEXT +SUB+ /Needed for
+ /Trace back
+ RTN, SETX XSUB /Reset SUB's index
+ SETB BSUB /And base page
+ BSUB, FNOP /Start of base page
+ JA .
+ .
+ .
+ ORG BSUB+30 /Restart for SUB
+ FNOP:JA RTN
+ GOBAK, FNOP:JA . /Return to
+ /Calling program
+
+ Location 00000 of the calling routine's base page points to the list
+ of arguments, if any, and may be used by the called subroutine
+ provided that it is not modified. Location 0003 of the calling
+ routine's base page is free for use by the called subroutine.
+
+ Location 0030 of the calling routine's base page contains the address
+ where execution is to continue upon exit from the subroutine, so that
+ a subroutine should not return from a JSR call via location 0 of the
+ calling routine:
+
+ CORRECT INCORRECT
+
+ FLDA 30 FLDA 0
+ JAC JAC
+
+ The "non-standard" return allows the calling routine to reset its own
+ index registers and base page before continuing in-line execution.
+ General initialization code for a subroutine would be:
+
+ SECT SUB
+ JA #ST
+ .
+ .
+ .
+ BASE 0
+
+ #ST, STARTD /So only 2 words
+ /Will be picked up
+ FLDA 30 /Get return JA
+ FSTA GOBAK /Save it
+ FLDA 0 /Get pointer to list
+
+ 2-8
+\f
+
+
+ SETX XSUB /Set SUB's XR
+ SETB BSUB /Set SUB's Base
+ BASE BSUB
+ INDEX XSUB
+ FSTA BSUBX /Store pointer
+ /Somewhere on Base
+ .
+ .
+ .
+ STARTF /Set F mode before
+ JA GOBAK /Return
+
+ The above code can be optimized for routines that do not require full
+ generality. The JA #ST around the base page code is a convenience
+ which may be omitted. The three words of text are necessary only for
+ error traceback and may also be omitted. If the subroutine is not
+ going to call any general subroutines, the SETX and SETB instructions
+ at location RTN and the JA RTN at location 0030 are not necessary. If
+ the subroutine does not require a base page, the SETB instruction is
+ not necessary in subroutine initialization; similar remarks apply to
+ index registers. If neither base page nor index registers are
+ modified by the subroutine, the return sequence:
+
+ FLDA 0
+ JAC
+
+ is also legal. In a subroutine call, the JA around the list of argu-
+ ments is unnecessary when there are no arguments. A RALF listing of
+ a FORTRAN source will provide a good reference of general FPP coding
+ conventions.
+
+ In order to generate good 8-mode code, one must be aware of the manner
+ in which the loader links and relocates RALF code. The loader handles
+ three 8-mode section types: COMMZ, FIELD1, and SECT8. All three
+ types of section are forced to begin and end on page boundaries and to
+ be a part of level MAIN; 8-mode sections never reside in overlays.
+ COMMZ and FIELD1 sections are forced to reside in field 1; SECT
+ sections may be in any field. The first COMMZ section encountered is
+ forced to begin at location 10000, thus enabling a page 0 in field 1.
+ COMMZ sections of the same name are handled like COMMON sections of
+ the same name (i.e., they are combined into one common section). This
+ feature allows 8-mode code in different modules to share page 0, pro-
+ vided that the modules do not destroy each other's page 0 allocations.
+ Suppose two modules were to share page 0, with the first using
+ location 0-17 and the second using locations 20-37:
+
+ /Module A
+ COMMZ SHARE
+ P1, 1
+ P2, 2
+ KSUBA1, SUBA1
+ KSUBA2, SUBA2
+ .
+ .
+
+ 2-9
+\f
+
+
+ . /Should not go over
+ LASTA, -1 /20 locations
+
+ FIELD1 A
+
+ TADZ P1
+ JMSZ% KSUBA1
+ .
+ .
+ . /Module B
+ COMMZ SHARE
+ ORG .+20 /ORG past module A's
+ /Page 0
+ P3, 3
+ P4, 4
+ KSUBB, SUBB
+ .
+ .
+ .
+ LASTB -2
+ FIELD1 B
+ TADZ P3
+ .
+ .
+ .
+
+ The two COMMZ sections will be put on top of one another, however,
+ because of the ORG .+20 in module B, they will effectively reside back
+ to back. When the image is loaded, the COMMZ sections will look as
+ follows:
+
+ LOC CONTENTS
+
+ 1 0000 1
+ 0001 2
+ 2 SUBA1
+ 3 SUBA2
+ .
+ .
+ .
+ 1 0017 -1 /LASTA
+ 1 0020 3
+ 21 4
+ 22 SUBB
+ .
+ .
+ .
+ 37 -2 /LASTB
+
+ If module A is to reference module B's page 0, the procedure is:
+
+ P3=20
+ TADZ P3
+
+
+ 2-10
+\f
+
+
+ Alternately, a duplicate of the source code for COMMZ SHARE may be
+ included in module B. Modules that are using the same COMMZ section
+ must be aware of how it is divided up. Although COMMZ SHARE takes only
+ 40 locations, the loader allocates a full 200 locations to it. All
+ 8-mode section core allocations are always rounded up so that they
+ terminate on a page boundary. If COMMZ sections of different names
+ exist, they are accepted by the loader and inserted into field 1, but
+ only one COMMZ is the real page 0. In general, it is unwise to have
+ more than 1 COMMZ section name.
+
+ FIELD1 sections are identical to COMMZ sections in most respects.
+ Memory allocation for FIELD1 sections is assigned after COMMZ sections,
+ however, and FIELD1 sections are combined with FORTRAN COMMON sections
+ of the same name as well as other FIELD1 sections of the same name.
+ The first difference ensures that COMMZ will be allocated page 0
+ storage even in the presence of FIELD1 sections. The second allows
+ PDP-8 code to be loaded into COMMON, making it possible to load
+ initialization code into data buffers. Two FIELD1 sections with the
+ same name may be combined in the same manner as two COMMZ, sections.
+
+ The primary purpose of COMMZ is to provide a PDP-8 page 0; the primary
+ purpose of FIELD1 is to ensure that 8-mode code will be loaded into
+ field 1 and that generating CIF CDF instructions in-line is not neces-
+ sary. SECT8 sections may not be combined in the manner of a COMMON
+ and are not ensured of being placed into field 1.
+
+ An 8-mode section does not have to be less than a page in length;
+ however, the programmer should be aware that a SECT8 section which
+ exceeds one page may be loaded across a field boundary and could
+ thereby produce disastrous results at execution time. For this
+ reason, it is generally unwise to cross pages in SECT8 code. This
+ situation will never occur on an 8K configuration. If the total
+ amount of COMMZ and FIELD1 code exceeds 4K, the loader generates an
+ OVER CORE message. The loader generates an MS error for any of the
+ following:
+
+ 1. A COMMZ section name is identical to some entry point or some
+ non-COMMZ section name.
+
+ 2. A FIELD1 section name is identical to some entry point or a
+ SECT, SECT8 or COMMZ section name.
+
+ 3. A SECT8 section name is identical to an entry point or some
+ other section name.
+
+ COMMZ sections, like FORTRAN COMMONS, are never entered in the library
+ catalog.
+
+ For users who intend to write 8-mode code that will execute in
+ conjunction with certain 8-mode library routines, the layout of PDP-8
+ FIELD1 #PAGE 0 is:
+
+
+
+
+ 2-11
+\f
+
+
+ LOCATION USE
+
+ 0-1 Temps for any non-interrupt time routine.
+ 2-13 User locations.
+ 14-157 System locations.
+ 160-177 User locations.
+
+ 1. Do not define any COMMZ sections other than the system COMMZ
+ which is #PAGE0.
+
+ 2. If the system page 0 is desired, it will be pulled in from
+ the library if EXTERN #DISP appears in the code.
+
+ 3. Do not use any part of page 0 reserved for the system.
+
+ Special purpose PDP-8 mode subroutines may be written to perform idle
+ jobs (refreshing a scope, checking sense lines) or to handle specific
+ interrupts not serviced by FRTS.
+
+ The run-time system enters idle loops while waiting for the FPP to
+ complete a task or for an I/O job to complete. It is possible to
+ effect a JMS to a user routine during the idle loop.
+
+ RTS contains a set of instructions such as:
+
+ #IDLE, JMP .+4
+ 0
+ CDF CIF
+ JMS I .-2
+
+ This sequence of instructions must be revised if an IDLE routine is to
+ be called.
+
+ The location #IDLE must be changed to a SKP (7410). #IDLE+1 must be
+ set to the address of the routine to be called. #IDLE+2 must be set
+ to a CDF CIF to the field of the routine. This setup can be done in a
+ routine that is called at the beginning of MAIN. For example:
+
+ CALL SETIDL
+
+ where SETIDL is a routine such as:
+
+ SECT8 SETIDL /Must be an 8-mode section
+ JA #RET
+ TEXT +SETIDL+ /Traceback information
+ SXR, SETX XR
+ SETB BP
+ BP, 0.0
+ XR, 0.0
+ .
+ .
+ .
+
+
+
+ 2-12
+\f
+
+
+ ORG 10*3+BP
+ FNOP /For trace back
+ JA SXR
+ .
+ 0
+ RET, JA . /Return address
+ .
+ .
+ .
+ #RET, STARTD /Set up
+ FLDA 10*3 /Return address
+ FSTA RET
+ SETB BP /Just for traceback
+ TRAP4 SET8 /Go to the 8 mode
+ /Routine set 8
+ STARTF
+ JA RET /Return to main
+ SET8, 0
+ TAD IDLAD /Field of idle
+ CLL RTL
+ RAL /Move to
+ /Bits 6-8
+ TAD SCDF /CDF to #IDLE
+ DCA .+3
+ TAD IDLAD+1 /Address of #IDLE
+ DCA IDPTR
+ 0 /CDF goes here
+ TAD S7410 /SKP
+ DCA% IDPTR /Store at #IDLE
+ TAD JOB+1 /Address of IDLE top routine
+ ISZ IDPTR
+ DCA IDPTR /Store a #IDLE+1
+ TAD JOB /Field of routine
+ CLL RTL
+ RAL /Position
+ TAD SFIELD
+ ISZ IDPTR
+ DCA% IDPTR /Store at #IDLE+2
+ CDF CIF /Set to field 0
+ JMP% SET8 /Return to instruction
+ /Following "TRAP4 SET8"
+ EXTERN #IDLE
+ IDLAD, ADDR #IDLE /15 bit address of IDLE
+ JOB, ADDR DOIT /15 bit address of IDLE
+ /Routine "DOIT"
+ SCDF, 6201 /CDF
+ SFIEL, 6203 /CDF CIF
+ IDPTR, 0
+ S7410, 7410 /Skip
+
+ /The following routine performs the
+ /IDLE task
+ /Executed during IDLE loops
+
+
+ 2-13
+\f
+
+
+ DOIT, 0
+ .
+ .
+ . /Perform task
+ .
+ CDF CIF 0 /Back to field 0
+ JMP% DOIT /And back
+
+ If the subroutine is checking for an illegal argument, an argument
+ error message with traceback can be included in the subroutine by
+ adding two lines somewhere on the base pages
+
+ EXTERN #ARGER
+ EXAMER, TRAP4 #ARGER
+
+ When the error is detected in the program, effect a jump to the TRAP4
+ instruction. For example,
+
+ FLDA% EXTMP1
+ JEQ EXAMER /A value of 0 is illegal
+ or
+
+ FLDA EXTMP1
+ FNEG
+ FADD EXTMP2
+ JLT EXAMER /The value in EXTMP1 must be
+ /greater than that in EXTMP2
+
+ Some points to note in the above example
+
+ 1. Using a # as the first character in the name of the start of the
+ program assumes that the name is not called from the FORTRAN level.
+ This is because # is an illegal FORTRAN keyboard character.
+
+ 2. If index registers 3-5 are not used by the subroutine, the space
+ from XR3 to the ORG statement can be used for temporary storage,
+ if needed.
+
+ 3. The arguments passed from the FORTRAN level do not have to be
+ picked up all at once at the start of the calculation (3-word)
+ portion of the program. They can be picked up as required during
+ the program, can be saved in temporary space, or accessed
+ indirectly each time required, as best suits the subroutine.
+
+ If a call to this routine such as Z=EXAMPL(A,B,C,D) were encountered
+ by the compiler, it would generate the following call to the routine:
+
+ JSR EXAMPL /go to the routine
+ JA .+10 /jump around arguments
+ JA A /pointer to lst argument
+ JA B /pointer to 2nd argument
+ JA C /pointer to 3rd argument
+ JA D /pointer to 4th argument
+
+
+ 2-14
+\f
+
+
+ The AMOD routine is listed below to illustrate an application of the
+ formal calling sequence. It also includes an error condition check
+ and picks up two arguments. When called from FORTRAN, the code is
+ AMOD(X,Y).
+
+ /
+ /
+ /
+ / A M O D
+ / - - - -
+ /
+ /SUBROUTINE AMOD(X,Y)
+ SECT AMOD /SECTION NAME(REAL NUMBERS)
+ ENTRY MOD /ENTRY POINT NAME(INTEGERS)
+ JA #AMOD /JUMP TO START OF ROUTINE
+ TEXT +AMOD + /FOR ERROR TRACE BACK
+ AMODXR, SETX XRAMOD /SET INDEX REGISTERS
+ SETB BPAMOD /ASSIGN BASE PAGE
+ BPAMOD, F 0.0 /BASE PAGE
+ XRAMOD, F 0.0 /INDEX REGS.
+ AMODX, F 0.0 /TEMP STORAGE
+ ORG 10*3+BPAMOD /RETURN SEQUENCE
+ FNOP
+ JA AMODXR
+ 0
+ AMDRTN, JA . /EXIT
+ EXTERN #ARGER
+ AMODER, TRAP4 #ARGER /PRINT AN ERROR MESSAGE
+ FCLA /EXIT WITH FAC=0
+ JA AMDRTN
+ BASE 0 /STAY ON CALLER'S BASE PG
+ /LONG ENOUGH TO GET RETURN ADDRESS
+ MOD, /START OF INTEGER ROUTINE SAME AS
+ #AMOD, STARTD /START OF REAL NUM. ROUTINE
+ FLDA 10*3 /GET RETURN JUMP
+ FSTA AMDRTN /SAVE IN THIS PROGRAM
+ FLDA 0 /GET POINTER TO PASSED ARG
+ SETX XRAMOD /ASSIGN MOD'S INDEX REGS
+ SETB BPAMOD /AND ITS BASE PAGE
+ BASE BPAMOD
+ LDX 1,1
+ FSTA BPAMOD
+ FLDA% BPAMOD,1 /ADDR OF X
+ FSTA AMODX
+ FLDA% BPAMOD,1+ /ADDR OF Y
+ FSTA BPAMOD
+ STARTF
+ FLDA% BPAMOD /GET Y
+ JEQ AMODER /Y=0 IS ERROR
+ JGT .+3
+ FNEG /ABS VALUE
+ FSTA BPAMOD
+ FLDA% AMODX /GET X
+ JGT .+5
+
+ 2-15
+\f
+
+
+ FNEG /ABS VALUE
+ LDX 0,1 /NOTE SIGN
+ FSTA AMODX /SAVE IN A TEMPORARY
+ FDIV BPAMOD /DIVIDE BY Y
+ JAL AMODER /TOO BIG.
+ ALN 0 /FIX IT UP NOW.
+ FNORM
+ FMUL BPAMOD /MULTIPLY IT.
+ FNEG /NEGATE IT.
+ FADD AMODX /AND ADD IN X.
+ JXN AM,1 /CHECK SIGN
+ FNEG
+ AM, JA AMDRTN /DONE
+
+ RTS has its own interrupt skip chain in which all on-line device flags
+ are checked and serviced. This chain may be extended to handle
+ special interrupts. The external tag #INT marks the first of three
+ locations on RTS which have to be modified to effect a JMS to the
+ user's special interrupt handler. The three locations must be set up
+ in exactly the same manner as that used to set up #IDLE, #IDLE1,
+ #IDLE2 as described above. All the same conventions hold. Refer also
+ to the library subroutines ONQI and ONQB.
+
+ Three pseudo-ops have been added to RALF to help the loader determine
+ core allocation. Each is a more definitive case of the SECT pseudo-op
+ and defines a chunk of code, thereby providing more control for the
+ user. They are:
+
+ SECT8 - section starts at a page boundary
+ FIELD1 - section starts at a page boundary and is in field 1
+ COMMZ - section starts at page 0 of field 1
+
+ If there is more than one SECT8 section in a module, those sections
+ are not necessarily loaded in contiguous core. The loader considers
+ core to be in two chunks - one block in field 0, and all of field 1
+ and above.
+
+ If there is more than one COMMZ pseudo-op in a module, they are
+ stacked one behind the other, but there is no way of specifying which
+ one starts at absolute location 0 of field 1. COMMZ sections are
+ allocated by the loader before FIELD1 sections.
+
+ Modules can share a COMMZ section in the same way that FORTRAN COMMON
+ sections can be shared. FIELD1 sections can also be shared by using
+ the same FIELD1 section name in each module.
+
+ The first occurrence of a section name defines that section. For
+ example,
+
+ SECT8 PARTA
+ .
+ .
+ .
+ SECT8 PARTB
+
+ 2-16
+\f
+
+
+ .
+ .
+ .
+ SECT8 PARTA
+
+ The second mention of PARTA in the same module continues the source
+ where the first mention of PARTA ended at execution time. (There is
+ a location counter for each section.)
+
+ To save core, a RALF FIELD1 section and FORTRAN COMMON section of the
+ same name are mapped on top of each other, being allocated the length
+ of the longer and the same absolute address by the loader. This
+ feature is useful for initialization (once-only) code, which can
+ later be overlayed by a data area. Thus, the occurrence of FIELD1
+ AREA1 in the RALF module and COMMON AREA1 in the FORTRAN program
+ causes AREA1 to start the same location (in field 1) and have a length
+ of at least 200 locations (depending on the length of the RALF FIELD1
+ section or of the COMMON section in the FORTRAN).
+
+ If the subroutine is longer than one page and values are to be passed
+ across page boundaries, the address pseudo-op, ADDR, is required.
+ The format is:
+
+ AVAR1, ADDR VAR1
+
+ This generates a two-word reference to the proper location on another
+ page, here VAR1. For example, to pass a value to VAR1, possible code
+ is:
+
+ 00124 1244 TAD VAR2 /Value on this page
+ 00125 3757 DCA% AVAR1+1 /Pass through 12-bit
+ . /location
+ 00156 0000 AVAR1,ADDR VAR1 /Field and
+ 00157 0322 /location of VAR1
+
+ Any reference to an absolute address can be effected by the ADDR
+ pseudo-op.
+
+ If it is doubtful that the effective address is in the current data
+ field, it is necessary to create a CDF instruction to the proper field.
+ In the above example, suitable code to add to specify the data field
+ is:
+
+ TAD AVAR1 /Get field bits
+ RTL /Rotate to bits 6-8
+ RAL
+ TAD (6201 /Add a CDF
+ DCA .+1 /Deposit in line
+ 0 /Execute CDFn
+
+ If the subroutine includes an off-page reference to another RALF
+ module (e.g., in FORLIB), it can be addressed by using an EXTERN
+ with an ADDR pseudo-op. For example, in the display program, a ref-
+ erence to the non-interrupt task subroutine ONQB is coded as
+
+ 2-17
+\f
+
+
+ EXTERN ONQB
+ ONQBX, ADDR ONQB
+
+ and is called by
+
+ JMS% ONQBX+1
+
+ The next instruction in the program is ADDR DISPLY so that DISPLY will
+ be added to the background list. Execution from ONQB returns after
+ the ADDR pseudo-op.
+
+ It may be desirable to salvage the first (field) word allocated by
+ ADDR pseudo-ops. If the address requires only twelve bite for proper
+ execution, code such as
+
+ TMP, TMP,ADDR X
+ ARG,ADDR X or ARG= .-1
+
+ permits TMP to be used for temporary storage because ARG+1 in the left
+ hand example or just ARG in the right hand example defines the 12-bit
+ address.
+
+ RALF does not recognize LINC instruction or PDP-8 laboratory device
+ instructions. Such instructions can be included in the subroutine by
+ defining them by equate statements in the program.
+
+ For example, adding the statements:
+
+ PDP = 2
+ LINC = 6141
+ DIS = 140
+
+ takes care of all instructions for coding the PDP-12 display
+ subroutine.
+
+ When writing a routine that is going to be longer than a page, it can
+ be useful to have a non-fixed origin in order not to waste core and to
+ facilitate modification of the code. A statement such as
+
+ IFPOS .-SECNAM&177-K<ORG .-SECNAM&7600+200+SECNAM>
+
+ will start a new page only if the value [current location less section
+ name] is greater than some K (start of section has a relative value of
+ 0) where K<=177 and is the relative location on the current page
+ before which a new page should be started. The ORG statement includes
+ an AND mask of 7600 to preserve the current page. When added to 200
+ for the next page and the section name, the new origin is set.
+
+ When calculating directly in a module, the following rules apply to
+ relative and absolute values.
+
+
+
+
+
+ 2-18
+\f
+
+
+ relative - relative = absolute
+ absolute + relative = relative
+ OR (!), AND (&) and ADD (+) of relative symbols
+ generate the RALF error message RE.
+
+ When passing arguments (single precision) from FPP code to PDP code,
+ using the index registers is very efficient. For example,
+
+ .
+ .
+ .
+ FLDA% ARG1 /Get argument in FPP mode
+ SETX MODE8 /Change index registers so XR0 is
+ /At MODE8
+ ATX MODE8 /Save argument
+ .
+ .
+ .
+ TRAP4 SUB8 /Go to PDP-8 routine
+ .
+ .
+ .
+ SUB8, 0 /PDP-8 routine
+ .
+ .
+ .
+ TAD MODE8 /Get argument
+ .
+ .
+ .
+ MODE8, 0 /Index registers set here
+ .
+ .
+ .
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ 2-19
+\f
+
+
+ CHAPTER 3
+
+ THE FORTRAN IV LOADER
+
+
+ The FORTRAN IV loader accepts a set of (up to 128) RALF modules as
+ input, and links the modules, along with any necessary library
+ components, to form a loader image file that may be read into memory
+ and executed by the run-time system. The main task accomplished by the
+ loader is program relocation, achieved by replacing the relative
+ starting address of every section with an absolute core address.
+ Absolute addresses are also assigned to all entry points, all
+ relocatable binary text, and the externs.
+
+ The loader executes in three passes. Pass 0 begins by determining how
+ much memory is available on the running hardware configuration, and
+ then constructs tables from the OS/8 command decoder input for use by
+ pass 1 and pass 2.
+
+ Pass 1 reads the relocatable binary input and creates the loader
+ symbol table. The length of each input module is computed and stored,
+ along with the relative values of entry points defined within the
+ input modules. When an undefined symbol is encountered, pass 1
+ searches the catalog of the FORTRAN IV library specified to pass 0,
+ or FORLIB.RL if no other library was explicitly specified, and loads
+ the library routine corresponding to the undefined symbol.
+
+ Pass 1 also allocates absolute core addresses to all modules and,
+ through them, to all symbols. Pass 1 execution concludes by computing
+ the lengths of all overlay levels defined for the current FORTRAN IV
+ job. Trap vectors are also set up at this time, and the tables
+ required for pass 2 loading are initialized.
+
+ Pass 2 concludes loader execution by creating a loader image file from
+ the relocated binary input and symbol values processed by pass 1.
+ Pass 2 also produces the loader symbol map, if requested, and chains
+ to the run-time system if /G was specified.
+
+ Pass 0 contains very few subroutines. The routine CORDSW checks for
+ the presence of /U, /C or /O option specifications, as supplied to the
+ command decoder, and processes these options if necessary. A routine
+ called UPDMOD is called when input to each overlay has been concluded,
+ to update the module counts in the module count table.
+
+ CORMOV is a general core-moving subroutine, called by the instruction
+ sequence:
+
+ JMS CORMOV
+ CDF FROMFIELD
+ FROMADDR - 1
+ CDF TOFIELD
+ TOADDR - 1
+ - COUNT
+
+
+ 3-1
+\f
+
+
+ LOADER PASS 0 (FILE COLLECTION)
+ ------------------------------
+ 00000 | OS/8 Command Decoder | FIELD 0
+ | |
+ | |
+ |----------------------------|
+ 02000 | Loader Pass 1 and |
+ | Pass 2 |
+ | |
+ |----------------------------|
+ 04600 | Core measuring routine |
+ | and scratch area to |
+ | save 00000-02000 |
+ | during CD calls |
+ |----------------------------|
+ 06600 | |
+ | Unused |
+ | |
+ |----------------------------|
+ 07600 | OS/8 Field 0 resident |
+ |----------------------------|
+ 10000 | OS/8 User Service Routine | FIELD 1
+ | |
+ | |
+ |----------------------------|
+ 12000 | Symbol table, loader map |
+ | titles |
+ 12400 | |
+ |----------------------------|
+ 13200 | Pass 0 code |
+ |----------------------------|
+ 14000 | Pass 1 initialization |
+ | |
+ | |
+ |----------------------------|
+ 16000 | Module count and |
+ | module tables |
+ |----------------------------|
+ 17000 | Library catalog header |
+ | read into this block |
+ |----------------------------|
+ 17600 | OS/8 Field 1 resident |
+ ------------------------------
+
+ while ERROR is the local error processing routine, called with a
+ pointer to the appropriate error message in the accumulator.
+
+ The major pass 1 and pass 2 subroutines, described below, operate on
+ the loader internal tables, whose format is presented later in this
+ chapter. The subroutines are presented in approximately the order
+ that they occur in the source listing.
+
+
+
+
+ 3-2
+\f
+
+
+ LOADER PASS 1 (SYMBOL RESOLUTION)
+ ------------------------------
+ 00000 | Pass 1 and Pass 2 | FIELD 0
+ | utility routines |
+ |----------------------------|
+ 01400 | Symbol map printer |
+ |----------------------------|
+ 02000 | Pass 2 |
+ |----------------------------|
+ 03200 | Pass 1 symbol collection |
+ |----------------------------|
+ 04000 | Inter-pass code allocates |
+ | storage, builds and writes |
+ | Loader Image Header Block. |
+ |----------------------------|
+ 04600 | Library catalog loads |
+ | here in 8K. Unused in |
+ | 12K or more. |
+ |----------------------------|
+ 07200 | Input device handlers |
+ |----------------------------|
+ 07600 | OS/8 Field 0 resident |
+ |----------------------------|
+ 10000 | ESD table | FIELD 1
+ | |
+ 11400 | |
+ |----------------------------|
+ 12000 | Symbol table |
+ |----------------------------|
+ 15400 | Overlay length table |
+ |----------------------------|
+ 16000 | Module count and module |
+ | tables (MCTTBL, MODTBL) |
+ |----------------------------|
+ 17200 | Loader header |
+ |----------------------------|
+ 17400 | ESD reference page |
+ |----------------------------|
+ 17600 | OS/8 Field 1 resident |
+ |----------------------------|
+ 20000 | Library catalog loads here | FIELD 2
+ | in 12K or more. |
+ |----------------------------|
+ 25000 | OS/8 BATCH processor if |
+ | 12K or more and BATCH |
+ | is running |
+ ------------------------------
+
+
+
+
+
+
+
+
+ 3-3
+\f
+
+
+ LOADER PASS 2 (LOADER IMAGE BUILDER)
+ -----------------------------------
+ 00000 | Utility routines: Symbol table | FIELD 0
+ | look-up, TTY message handler, |
+ | OS/8 block I/O, MCTTBL |
+ | processor. |
+ |---------------------------------|
+ 01400 | Routine to print symbol map. |
+ |---------------------------------|
+ 02000 | Pass 2 |
+ |---------------------------------|
+ 03200 | Binary buffer #1 |
+ | |
+ |---------------------------------|
+ 05200 | Binary buffer #2 |
+ | |
+ |---------------------------------|
+ 07200 | I/O device handlers |
+ |---------------------------------|
+ 07600 | OS/8 Field 0 resident |
+ |---------------------------------|
+ 10000 | RALF module text loads | FIELD 1
+ | here if 8K. |
+ |---------------------------------|
+ 12000 | Symbol table |
+ | |
+ |---------------------------------|
+ 15400 | Overlay length table |
+ |---------------------------------|
+ 16000 | MCTTBL and MODTBL | -
+ |---------------------------------| |
+ 17200 | Binary section table and | > symbol map
+ | binary buffer (LDBUFS) table | | output buffer
+ |---------------------------------| |
+ 17400 | ESD reference page | -
+ |---------------------------------|
+ 17600 | OS/8 Field 1 resident |
+ |---------------------------------|
+ 20000 | Binary buffer #3, if >8K | FIELD 2
+ |---------------------------------|
+ 22000 | Binary buffer #4, if >8K |
+ |---------------------------------|
+ 24000 | Binary buffer #5, if >12K |
+ |---------------------------------|
+ 26000 | Unused |
+ |---------------------------------|
+ 30000 | RALF module text loads | FIELD 3
+ | here if >12K |
+ -----------------------------------
+
+
+
+
+
+
+ 3-4
+\f
+
+
+ SETBPT Sets words BPTR and BPT2 to contain AC and AC+1,
+ respectively.
+
+ TTYHAN Subroutine to unpack and print a TEXT message on the
+ console terminal. TTYHAN is called by:
+
+ CDF CURRENT
+ CIF 0
+ JMS TTYHAN
+ CDF MSGFIELD
+ MSG
+
+ RTNOS8 Prints a fatal error message and then returns to the
+ OS/8 monitor. A pointer to the message must follow
+ the JMS RTNOS8.
+
+ IOHAN Used to execute all I/O under OS/8. The calling
+ sequence is:
+
+ TAD (ACARG /Optional
+ CDF CURRENT
+ CIF 0
+ JMS IOHAN
+ ADDR
+ ARG1
+ ARG2
+ ARG3
+
+ where ARG1, ARG2 and ARG3 are standard OS/8 device
+ handler arguments and ADDR points to a three-word block
+ in field 1 which contains the OS/8 unit number in word
+ 1, the file length in word 2, and the starting block
+ number in word 3.
+
+ If ACARG is zero, the indicated I/O operation is
+ executed after the handler has been FETCHed, if
+ necessary. If ACARG=n (greater than zero), the handler
+ for OS/8 unit n is FETCHed, no I/O is done, and the
+ four arguments that conclude the calling sequence are
+ not needed.
+
+ ADVOVR Called to initialize the loader to accept a new input
+ module. ADVOVR determines whether a new overlay or
+ level is being started by accessing the module count
+ table. If so, it sets various pointers and internal
+ counters accordingly, rounds the previous overlay to
+ terminate on a 200 word boundary, and updates the
+ length of the previous level, if necessary, as the
+ maximum of its constituent overlay lengths.
+
+ NXTOVR Called by ADVOVR when the next input module will be the
+ first module in a new overlay.
+
+
+
+ 3-5
+\f
+
+
+ SETCNT Initializes the pointers and counters used by ADVOVR.
+ SETCNT is called once at the beginning of each pass.
+
+ LOOK Executes a symbol look-up in the loader symbol table.
+ LOOK is called by:
+
+ TAD (Pointer to symbol name in
+ RALF ESD format
+ JMS LOOK
+ RETURN here if not found
+ RETURN here if found
+ GPTR points to word following entry name
+
+ If the symbol is not found, it is inserted into the
+ loader symbol table and GPTR is set to point to the
+ word following the symbol name.
+
+ SYMMAP Produces the symbol map.
+
+ PUTSYM Enters an ESD symbol in the loader symbol table. PUTSYM
+ calls LOOK to determine whether the symbol is already
+ present in the symbol table and, if so, verifies that
+ the symbol is not multiply defined. Otherwise, it
+ copies the ESD data words into the symbol table entry,
+ updates the length of the current overlay by the length
+ associated with the symbol, and links the symbol to its
+ parent symbol, if any.
+
+ FIT Fits a section into core by subtracting its length from
+ the amount of core still available and substituting its
+ load address for its length in the symbol table.
+
+ DO8S, FIT8S Fits an 8-mode section into core by calling FIT and
+ then checking for field 1 overflow.
+
+ SETREF Extracts data from the ESD table of the current module
+ and initializes the ESD reference page at 17400.
+
+ BLDTV Builds the transfer vector. A transfer vector entry
+ is created for each subroutine in an overlay. This
+ entry provides the information that the run-time system
+ will require in order to load the overlay containing
+ the referenced subroutine.
+
+ NEWORG Called whenever an origin is found in an input module,
+ to map the location referenced by the origin into a
+ block of the loader image file and an address within
+ that block.
+
+ NEWBB Called whenever a new binary buffer is needed during
+ loader image file construction. NEWBB scans a list of
+ available buffers and dumps the content of the least
+ recently accessed buffer to free up space for new data.
+
+
+ 3-6
+\f
+
+
+ MERGE Relocates an input word pair and outputs it to the
+ loader image file.
+
+ GETCTL Gets a control byte from the input module and incre-
+ ments its return address by the content of the control
+ byte.
+
+ PUTBIN Inserts words, sequentially, into the current binary
+ buffer. When the buffer is full, PUTBIN calls NEWBB to
+ execute output to the loader image file and supply a
+ new buffer.
+
+ TXTSCN Called once for each input module. TXTSCN reads and
+ relocates an entire input module, executing calls to
+ MERGE, PUTBIN and NEWORG as needed.
+
+
+
+ SYMBOL TABLE
+
+
+
+ The loader symbol table begins at location 12000 and contains room for
+ 26 (decimal) permanent system symbol entries and 218 (decimal) user
+ entries. Each entry is 7 words long, and provides the name and
+ definition of a symbol. The table is organized in buckets according
+ to the first character of the symbol, which must be A to Z, #, or
+ blank (for blank COMMON). The table of bucket pointers begins at
+ location 12000 with the pointer to bucket A, and consists of one word
+ per bucket. This word contains a value of zero, if there are no
+ symbols in the corresponding bucket, or else the address of the first
+ symbol in the bucket.
+
+ Symbols within a bucket are arranged in alphabetical order, with each
+ symbol entry pointing to the following entry, and the last entry
+ pointing to zero. Thus, the symbol table appears as a set of threaded
+ lists in core. The format of a symbol table entry is:
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ 3-7
+\f
+
+ ------------------------------
+ | Pointer to next symbol in |
+ | bucket (zero if none). | WORD 1
+ |----------------------------|
+ | S | Y | WORD 2
+ |----------------------------|
+ | M | B | WORD 3
+ |----------------------------|
+ | O | L |
+ |----------------------------|
+ | | 3-bit | 4-bit | |
+ | * | level | overlay | ** |
+ | | # | # | |
+ |----------------------------|
+ | 9-bit pointer to | |
+ | parent symbol | |
+ | during pass 1 | |
+ | (zero if none). | Field |
+ | Trap vector | bits |
+ | displacement | |
+ | during pass 2. | |
+ |----------------------------|
+ | ADDRESS |
+ | (Length during pass 1) |
+ ------------------------------
+
+
+ * 1-bit trap vector flag during pass 1. Error flag during pass 2.
+
+ ** 4-bit type code
+ 0- undefined
+ 1- entry point
+ 2- extern
+ 3- common sect
+ 4- program sect
+ 5- multiple entry point
+ 6- multiple sect
+ 7- SECT8 sect
+ 10- COMMZ
+ 11- FIELD1
+ 12 to 17- undefined
+
+ Several special symbols are created by the loader. The symbol #YLVLn,
+ where n is an octal digit, describes overlay level n. This symbol
+ table entry contains the length of level n during pass 1 and the
+ starting address of level n during pass 2.
+
+ The symbol #YTRAP describes the trap vector, a method by which the
+ run-time system controls automatic overlaying of user subroutines.
+ Four words are allocated in the trap vector for each entry point in
+ every overlay except overlay #MAIN. The symbol table entry for #YTRAP
+ contains the accumulated length of the trap vector during pass 1 and
+ the trap vector starting address during pass 2.
+
+
+
+ 3-8
+\f
+
+
+ ESD CORRESPONDENCE TABLE (ESDPG)
+
+
+
+ The ESD correspondence table begins at location 17400 and contains 128
+ (decimal) 1-word entries. This table establishes the correspondence
+ between the local ESD reference numbers used to reference a symbol
+ inside a RALF module, and the address of that symbol in the loader
+ symbol table. The nth entry in the ESD correspondence table points to
+ the address of ESD symbol n.
+
+
+
+ BINARY BUFFER TABLE (LDBUFS)
+
+
+
+ The binary buffer table begins at location 17247 and contains from two
+ to ten entries, depending upon the amount of memory available. Each
+ entry is 4 words in length. The binary buffers function as windows
+ into the loader image file, through which the loaded program is
+ written onto mass storage. Each binary buffer is 8 pages (4 OS/8
+ blocks) in length. The loader tries to minimize the amount of "window
+ turning" necessary to buffer the binary data by keeping a record of
+ the last time each buffer was referenced. In this way, when the
+ content of a binary buffer must be dumped to make room for new data,
+ the loader empties that buffer which was least recently used.
+
+ In addition, program loading is overlay oriented such that only one
+ overlay is loaded at a time and while any specific overlay is being
+ loaded, only origins inside that overlay are legal.
+
+ The format of a binary buffer table entry is:
+
+ ------------------------------------
+ | Pointer to the binary buffer of |
+ | "next earliest reference", i.e., |
+ | the youngest buffer older than | WORD 1
+ | this buffer. Contains zero if |
+ | this buffer is oldest. |
+ |----------------------------------|
+ | Loader image block #. Contains |
+ | zero if buffer has not been used.| WORD 2
+ |----------------------------------|
+ | Blocks left in current overlay |
+ | If <4, only part of buffer will | WORD 3
+ | be dumped. |
+ |----------------------------------|
+ | Page address | Buffer | |
+ | of buffer. | field | Unused | WORD 4
+ | | bits | |
+ ------------------------------------
+
+
+
+ 3-9
+\f
+
+
+ The number of binary buffers used varies with the amount of memory
+ available as follows:
+
+ -------------------------------------------
+ MEMORY | NO. OF
+ AVAIL | BUFFERS
+ -------------------|-----------------------
+ 8K | 2
+ 12K | 4
+ 16K | 5
+ 20K | 7
+ 24K | 10 (decimal)
+ 28K | 10 (decimal)
+ 32K | 10 (decimal)
+ -------------------------------------------
+
+
+
+ BINARY SECTION TABLE
+
+
+
+ The binary section table overlays the loader image header block
+ (described under FRTS) after the latter has been written into the
+ loader image file at the beginning of pass 2. Thus, the binary
+ section table begins at location 17200 and contains eight 4-word
+ entries. Each entry relates the core origin of one of the eight
+ overlay levels to that level's position in the loader image file.
+ The format of a binary section table entry is:
+
+ -----------------------------------
+ | | Field |
+ | Unused | of | WORD 1
+ | | level |
+ |---------------------------------|
+ | Address of level | WORD 2
+ |---------------------------------|
+ | Relative block # | WORD 3
+ |---------------------------------|
+ | Length (in blocks) | WORD 4
+ -----------------------------------
+
+
+ OVERLAY TABLE (OVLTBL)
+
+
+ The overlay table begins at location 15435 and contains room for 113
+ (decimal) 2-word entries. There is one entry for each overlay
+ defined, including overlay MAIN, with each entry designating the
+ length in words, of the corresponding overlay. The format of an
+ overlay table entry is:
+
+
+
+
+ 3-10
+\f
+
+
+ OVLTBL
+ -----------------------
+ | LEVEL MAIN |
+ |---------------------| Negated to indicate
+ | LEVEL 1 OVERLAY 1 | last table entry
+ |--------/\/----------| /
+ . - /
+ . | ------------------- /
+ . | | HIGH-order bits |/
+ |--------/\/----------| | | of length | WORD 1
+ | LEVEL m OVERLAY n-1 |>----< |-----------------|
+ |---------------------| | | LOW-order bits |
+ | LEVEL m OVERLAY n | | | of length | WORD 2
+ |---------------------| | -------------------
+ | OVLTBL format | - individual entry (2 words)
+ -----------------------
+
+
+
+ MODULE DESCRIPTOR TABLE (MODTBL)
+
+
+
+ The module descriptor table begins at location 16172 and contains
+ room for 172 (decimal) 3-word entries. Each entry provides the
+ information needed to locate an input module. The first MODTBL entry
+ corresponds to the library file to be used in building the current
+ loader image. Successive entries correspond to input modules and
+ appear in the order that the modules were specified by the user,
+ (i.e., in ascending order by level, and ascending by overlay within
+ any given level.) At the end of pass 1, entries corresponding to
+ individual library modules are appended to the end of the table, even
+ though the library modules load into level MAIN. The table format is:
+
+
+ MODTBL
+ --------------------------------
+ | FORLIB.RL or user- |
+ | specified library | -
+ |------------------------------| | --------------------------
+ | Level MAIN module #1 | | | OS/8 I/O unit # |
+ |------------------------------| | |------------------------|
+ | Level MAIN module #2 | < | File length (positive) |
+ |------------------------------| | |------------------------|
+ | Level MAIN module #3 | | | Starting block # |
+ |----/\/----------------\/\----| | --------------------------
+ -
+ |----/\/----------------\/\----|
+ | Level MAIN module n | MODTBL format of
+ |------------------------------| individual entry (3 words)
+ | Level 1 Overlay 1 module #1 |
+ |------------------------------|
+ | Level 1 Overlay 1 module #2 |
+ |----/\/----------------\/\----|
+
+ 3-11
+\f
+
+
+ |----/\/----------------\/\----|
+ | Level 1 Overlay 1 module #n |
+ |------------------------------|
+ | Level 1 Overlay 2 module #1 |
+ |----/\/----------------\/\----|
+ .
+ .
+ .
+ |----/\/----------------\/\----|
+ | Level m Overlay n module #p |
+ |------------------------------|
+ | Library module #1 |
+ |------------------------------|
+ | Library module #2 |
+ |----/\/----------------\/\----|
+
+ MODTBL format
+
+
+
+ MODULE COUNT TABLE (MCTTBL)
+
+
+
+ The module count table begins at location 16000 and contains room for
+ 122 (decimal) 1-word entries that give the (two's complement) module
+ count for each overlay level. The table format is:
+
+
+ MCTTBL
+ -------------------------
+ | LEVEL MAIN | 1-word ENTRIES
+ |-----------------------|
+ | 0 |
+ |-----------------------|
+ | LEVEL 1 OVERLAY 1 |
+ |-----------------------|
+ | LEVEL 1 OVERLAY 2 |
+ |-----------------------|
+ | LEVEL 1 OVERLAY 3 |
+ |----/\/---------\/\----|
+
+ |----/\/---------\/\----|
+ | LEVEL 1 OVERLAY n |
+ |-----------------------|
+ | 0 |
+ |-----------------------|
+ | LEVEL 2 OVERLAY 1 |
+ |-----------------------|
+ | LEVEL 2 OVERLAY 2 |
+ |----/\/---------\/\----|
+
+
+
+
+ 3-12
+\f
+
+
+
+ |----/\/---------\/\----|
+ | LEVEL 2 OVERLAY n |
+ |-----------------------|
+ | 0 |
+ |-----------------------|
+ | LEVEL 3 OVERLAY 1 |
+ |----/\/---------\/\----|
+ .
+ .
+ .
+ |----/\/---------\/\----|
+ | LEVEL m OVERLAY n |
+ |-----------------------|
+ | 0 |
+ |-----------------------|
+ | 0 |
+ -------------------------
+
+ If an overlay or level is not defined for a specific program, there is
+ no module count table entry corresponding to that overlay or level.
+
+ The loader image file, produced by the loader and read as input by the
+ run-time system, consists of a header block followed by a binary image
+ of each level defined in the FORTRAN IV job.
+
+ ----------------------------------- -----------
+ | HEADER | LEVEL | LEVEL / / LEVEL |
+ | BLOCK | MAIN | 1 \ \ n |
+ | | | / / |
+ ---------------------------------- ------------
+
+
+ The loader image file header block contains information in the
+ following format:
+
+ LOCATION CONTENTS
+ 0 2 -- Identifies the file as a loader image file.
+ 1-2 Initial SWAP arguments to load level MAIN.
+ 3-4 Highest address used by core load, including overlays
+ but not including OS/8 device handlers.
+ 5 Loader version number.
+ 6 Double-precision flag.
+ 7-46 User overlay information table containing one 4-word
+ entry per overlay level (the level MAIN entry is
+ ignored) in the following format:
+
+
+
+
+
+
+
+
+
+ 3-13
+\f
+
+
+ ---------------------------------------
+ | Unused until SWAP time. Must | WORD 1
+ | be positive or zero. |
+ |-------------------------------------|
+ Load | Page | Bits 4-5 | Field | Bits 9-11 | WORD 2
+ address ---> | bits | unused | bits | unused |
+ |-------------------------------------|
+ | Block number of this level, | WORD 3
+ | relative to header block. |
+ |-------------------------------------|
+ | Length of overlays in this level, | WORD 4
+ | in blocks. |
+ ---------------------------------------
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ 3-14
+\f
+
+
+ CHAPTER 4
+
+ THE FORTRAN IV RUN-TIME SYSTEM
+
+
+ The FORTRAN IV run-time system supervises execution of a FORTRAN job
+ and provides an I/O interface between the running program and the OS/8
+ operating system. FRTS includes its own loader, which should not be
+ confused with LOAD, the system loader. It executes with only one
+ overlay, used to restore the resident monitor and effect program
+ termination. The run-time system was designed to permit convenient
+ modification or enhancement, and it is well documented in the assembly
+ language source, available from the Software Distribution Center,
+ which includes extensive comments.
+
+ One of the most valuable modifications to FRTS provides for the
+ inclusion of background (or idle) jobs. When FORTRAN is waiting for
+ I/O operations or the FPP to complete execution, the PDP-8 or PDP-12
+ processor is sitting in an idle loop. An idle job may be executed by
+ the PDP-8 or PDP-12 CPU during this time, perhaps for the purpose of
+ refreshing a CRT display, for example, or monitoring a controlled
+ process. To indicate such a job, the idle wait loop must be modified
+ to include a reference to the user's PDP-8 routine. The routine #IDLE
+ in FRTS must be changed as part of the user's subroutine from
+
+ #IDLE, JMP .+4 to #IDLE, SKP
+ 0 ADDUSR
+ CDF CIF FLDUSR
+ JMS I .-2 JMS I .-2
+
+ Devices issuing interrupts may be added to the interrupt skip chain so
+ that FORTRAN checks the user's device as well as system devices. The
+ original code is:
+
+ #INT, JMP .+4
+ 0
+ CDF CIF
+ JMS I .-2
+
+
+ and must be changed, as above, to:
+
+ #INT, SKP
+ ADDUSR
+ FLDUSR
+ JMS I .-2
+
+ In both cases, ADDUSR should be the address of the user's routine, and
+ FLDUSR should be the memory field of the user's routine.
+
+ The idle job is initiated by the subroutine HANG in the run-time
+ system. Hang should only be called when the FORTRAN program must wait
+ for an I/O device flag. The calling sequence is:
+
+
+ 4-1
+\f
+
+
+ EXTERN #HANG
+ IOF /Important.
+ CDF n /Where n is current field.
+ CIF 0
+ JMS% HANG+1
+ ADDRSS
+ /Return here with interrupts OFF
+ /When device flag is raised.
+
+ HANG, ADDR #HANG
+
+ The word ADDRSS must point to a location in page 400 of the run-time
+ system which must normally contain a JMP DISMIS. Three such locations
+ have been provided for the user at #DISMS, #DISMS+1, and #DISMS+2. The
+ selected location must be the location via which the interrupt caused
+ by the desired flag is dismissed. No two flag routines should use the
+ same dismiss location. The following program example illustrates
+ these calling conventions. This routine may be used to drive a
+ Teletype terminal via the PT08 option.
+
+ EXTERN #ONQI
+ EXTERN #DISMS
+ FIELD1 GETCH /JMS GETCH GETS A CHAR
+ 0 /GETCH RUNS IN FIELD I ONLY
+ ISZ FIRST
+ JMP NOTFST
+ JMS% ONQI+1
+ KSF1
+ ADDR KSFSUB
+ TAD DISMIS+1 /SET UP TO CALL HANG
+ DCA HNGLOC
+ NOTFST, IOF
+ TAD INCHR
+ SZA CLA
+ JMP GOT1
+ CIF 0
+ JMS% HANG+1 /NO CHAR READY: HANG
+ HNGLOC, 0
+ /HANG RETURNS W/ IOF
+ GOT1, TAD INCHR
+ DCA FIRST
+ DCA INCHR
+ TAD FIRST
+ ION
+ JMP% GETCH
+ /INTERRUPT ROUTINE -
+ KSFSUB, 0 /CALLED AS SUBROUTINE
+ KRB1
+ DCA INCHR
+ CDF CIF 0
+ JMP% DISMIS+1 /RETURN TO SYSTEM LOCATION
+ /CONTAINING "JMP DISMIS"
+ INCHR, 0
+ ONQI, ADDR #ONQI
+
+ 4-2
+\f
+
+
+ HANG, ADDR #HANG
+ DISMIS, ADDR #DISMS
+ FIRST, -1
+
+ In most cases, it is easier to include references to the FORLIB module
+ ONQI for adding a handler to the interrupt skip chain and ONQB for
+ adding a job to the idle chain, instead of trying to modify #IDLE and
+ #INT. ONQB provides slots for up to 9 idle jobs to be executed
+ round-robin, and ONQI provides for up to 9 user flags to be tested on
+ program interrupts.
+
+ FRTS entry points are listed, along with the core map, on the
+ following pages. The FRTS calling sequence must be observed in any
+ user subroutine. The formal calling sequence is illustrated below. In
+ general, it can be used exactly as illustrated, changing only the
+ section, entry, base page, index register and return location names.
+
+
+
+ FRTS CALLING SEQUENCE
+
+
+
+ SECT EXAMPL /Section name. Your module may
+ /require another section pseudo-op
+ /such as FIELD1 or SECT8.
+ JA #EXSRT /Jump to start of subroutine
+ /Use # for first character
+ TEXT +EXAMPL+ /6 character section name for
+ /error traceback (optional)
+ EXAMXR, SETX XREXAM /Set up index registers
+ /for this subroutine
+ SETB BPEXAM /and its base page.
+ BPEXAM, F 0.0 /Base page
+ XREXAM, F 0.0 /Index registers 0-2
+ F 0.0 /Index registers 3-5 (optional)
+ EXTMP1, F 0.0 /Space between index registers
+ EXTMP2, F 0.0 /and the ORG for temporary
+ EXTMP3, F 0.0 /storage (optional)
+ ORG 10*3+BPEXAM /Location 30 of base page
+ FNOP /Force a two-word instruction
+ JA EXAMXR /Jump to base page for
+ /return to calling program
+ 0 /Force a two-word instruction
+ EXMRTN, JA . /Will be replaced by return jump
+ BASE 0 /Caller's base page
+ #EXSRT, STARTD /Start of subroutine
+ FLDA 10*3 /Get return jump from caller's
+ /base page
+ FSTA EXMRTN /Save in return location for
+ /this routine
+ FLDA 0 /Location 0 of caller's routine
+ /is a pointer to the argument list
+ SETX XREXAM /Change to EXAMPL's index registers
+
+ 4-3
+\f
+
+
+ SETB BPEXAM /Change to EXAMPL's base page
+ BASE BPEXAM
+ FSTA BPEXAM /Save the pointer
+ LDX 1,1 /Set up index register 1
+ FLDA% BPEXAM, 1 /Get address of argument list
+ FSTA EXTMP1 /Save the addresses
+ FLDA% BPEXAM, 1+ /of all passed arguments
+ FSTA EXTMP2
+ FLDA% BPEXAM, 1+
+ FSTA EXTMP3 /Continue for all arguments
+ . /to be picked up
+ .
+ .
+ STARTF /Start three-word instructions
+ FLDA% EXTMP1
+ .
+ .
+ .
+ FLDA% EXTMP2
+ .
+ .
+ . /Continue to get arguments
+ . /as required in routine
+ JA EXMRTN /Exit when done
+
+
+
+ RTS ENTRY POINT USEAGE AND COMMENTS
+
+ #UE TRAP3 #UE /Produces USER ERROR error message.
+
+ #ARGER or TRAP4 #ARGER /Produces BAD ARG error message.
+ #ARGERR
+
+ #READO TRAP3 #READO /Initializes
+ JA UNITNO /formatted
+ JA FORMAT /read operation.
+
+ #WRITO TRAP3 #WRITO /Initializes
+ JA UNITNO /formatted
+ JA FORMAT /write operation.
+
+ #RUO TRAP3 #RUO /Initializes unformatted
+ JA UNITNO /read operation.
+
+ #WUO TRAP3 #WUO /Initializes unformatted
+ JA UNITNO /write operation.
+
+ #RDAO TRAP3 #RDAO /Initializes
+ JA UNITNO /direct access
+ JA RECNO /read operation.
+
+
+
+
+ 4-4
+\f
+
+
+ #WDAO TRAP3 #WDAO /Initializes
+ JA UNITNO /direct access
+ JA RECNO /write operation.
+
+ #RFSV TRAP3 #RFSV /Passes a variable to or from the read/
+ /write processors via the floating AC.
+
+ #RENDO TRAP3 #RENDO /Terminates a read/write operation.
+
+ #ENDF FLDA UNITNO /Executes an
+ TRAP3 #ENDF /end file,
+ #REW or TRAP3 #REW /rewind,
+ #BAK or TRAP3 #BAK /backspace (depending upon the entry used)
+ /on the referenced I/O unit.
+
+ #DEF TRAP3 #DEF /Opens a file
+ JA UNITNO /for direct access I/O.
+ JA RECORDS
+ JA FPNPR /(FPP numbers per record)
+ JA VARIABLE /Refer to DEFINE FILE statement
+
+ #EXIT JSR #EXIT /Terminates current FORTRAN IV job.
+
+ #SWAP TRAP3 #SWAP /Reads overlay OVLY into level LVL and
+ ADDR /jumps to ADR. ADDR is given by:
+ /ADDR=4000000*OVLY+100000*LVL+ADR
+
+ #8OR12 /=00000001 if the CPU is a PDP-12.
+
+ #IDLE Address of background job, used by ONQB. Contains:
+
+ JMP I (NULJOB /Replace by SKP
+ 0 /Replace by addr of background job
+ CDF CIF 0 /Replace by field of background job
+ JMS I .-2
+ JMP .-4
+
+
+
+ CORE LAYOUT OF FRTS
+
+ NON-FPP FPP (Same as non-FPP
+ unless indicated)
+ -----------------------------------
+ 0000 | Page zero (0120-0134 free) |
+ |---------------------------------|
+ 0200 | Most entry points, character |
+ | I/O handlers, interrupt |
+ | service, and HANG routine |
+ |---------------------------------|
+ 0600 | Format decoder; A, H, and ' |
+ | format processors, and EXIT |
+ |------\/\---------------/\/------|
+
+
+ 4-5
+\f
+
+
+ |------\/\---------------/\/------|
+ 1400 | REWIND, ENDFILE, BACKSPACE and |
+ | general unit initialization |
+ | DATABL table (3wds/unit) |
+ |---------------------------------|
+ 2000 | I, E, F and G output |
+ |---------------------------------|
+ 2400 | I, E, F and G input |
+ |---------------------------------|
+ 2600 | X, L and T formats and |
+ | GETHND routine |
+ |---------------------------------|
+ 3000 | Char in and char out routines |
+ | including OS/8 packing, editing |
+ | and forms control |
+ |---------------------------------|
+ 3400 | Binary and D. A. I/O, and |
+ | DEFINE FILE processor |
+ |---------------------------------|
+ 3600 | Overlay loader |
+ |---------------------------------|
+ 4000 | Input line buffer, overlay |
+ | and DSRN tables, FORMAT |
+ | parenth pushdown list, /P |
+ | processor and init flag clear |
+ |---------------------------------|
+ 4400 | Floating-point utilities (shift,|
+ | add, etc.) used even w/FPP |
+ |---------------------------------|
+ 4600 | Error routine and messages |
+ |---------------------------------|
+ 5200 | OS/8 handler area and part of |
+ | FRTS loader initialization |
+ |---------------------------------|-----------------------------
+ 5600 | FPP simulator | FPP start-up and trap |
+ | | routines |
+ | |----------------------------|
+ 6000 | | B and D format I/O |
+ |---------------------------------|----------------------------|
+ 6600 | Floating-point package and | Floating-point package |
+ | part of LPT ring buffer | (never used) and part of |
+ | | LPT ring buffer |
+ |---------------------------------|-----------------------------
+ 7400 | Most of LPT ring buffer |
+ |---------------------------------|
+ 7600 | OS/8 handler and field |
+ | 0 resident |
+ |---------------------------------|
+ 10000 | OS/8 User Service Routine |
+ |---------------------------------|
+ 12000 | FRTS loader tables, IONTBL | Locations 12000 to 17400 are
+ | | overlayed at execution time
+ |------\/\---------------/\/------|
+
+
+ 4-6
+\f
+
+
+ |------\/\---------------/\/------|
+ 12200 | FRTS loader: main flow |
+ |---------------------------------|
+ 12400 | program start-up (1) |
+ |---------------------------------|
+ 12600 | initialize and |
+ | configure system |
+ |---------------------------------|
+ 13000 | Load OS/8 handlers and assign |
+ | unit numbers to OS/8 files |
+ |---------------------------------|
+ 13400 | Utility and error routines, |
+ | error messages |
+ 14000 | |
+ |---------------------------------|
+ 15600 | FPP start-up and trap routines | Locations 14000 to 16777 are
+ |---------------------------------| used to save lower field 0
+ 16000 | B and D format I/O | during loading of device
+ |---------------------------------| handlers and file
+ 16600 | EAE Floating-point package | specifications
+ |---------------------------------|
+ 17400 | Termination routine | Locations 17400 to 17777 are
+ |---------------------------------| written on SYS block 37
+ 17600 | OS/8 field 1 resident | before program load and
+ |---------------------------------| restored on termination
+
+
+
+
+
+ #INT /Address of user interrupt location, used by ONQI:
+
+ JMP .+4 /Replace with SKP
+ 0 /Replace with address of interrupt
+ processor
+ CDF CIF 0 /Replace with field of interrupt
+ processor
+ JMS I .-2
+
+ #DISMS /Addresses first of three JMP DISMIS instructions
+ for use by specialized I/O routines.
+
+ #HANG /Addresses I/O dismiss routine.
+
+ #RETRN /Provides return from TRAP3.
+
+
+
+
+ ------------------------
+ (1) Program start-up moves OS/8 handler to top of core, writes field
+ 1 resident onto SYS, and termination routine goes to FRTS to load
+ program.
+
+
+ 4-7
+\f
+
+
+ DSRN TABLE
+
+
+
+ The DSRN table controls files and I/O devices used under OS/8 FORTRAN
+ IV ASCII, binary and direct access I/O operations, including
+ BACKSPACE, REWIND, and END FILE operations. The exact meaning of the
+ initials DSRN is one of the great, unanswered questions of FORTRAN IV
+ development and, as such, has considerable historical interest. The
+ DSRN table provides room for 9 entries; each entry is 9 words in
+ length, and contains the following data:
+
+ WORD 1: (HAND) Handler entry point. If this value is positive, the
+ I/O device handler is a FORTRAN internal (character-oriented)
+ handler, and the remainder of the DSRN table entry is
+ ignored. If the value is negative, the handler is an OS/8
+ device handler whose entry point is the two's complement of
+ the value. Entry points always fall in the range [7607,
+ 7777] for resident handlers or [5200, 5377] for non-resident
+ handlers. Space for non-resident handlers is allocated
+ downward from the top of memory, and the handlers are moved
+ into locations 5200 to 5577 before being called.
+
+ WORD 2: (HCODEW) Handler code word. Bits 0-4 of this word specify
+ the page into which the device handler was loaded, while bits
+ 6-8 specify the memory field. If all of bits 0-8 are zero,
+ the handler is permanently resident. When any of these bits
+ are non-zero, the data is used to determine which handler, if
+ any, currently occupies locations 5200-5577. This eliminates
+ unnecessarily moving the content of memory. Bit 10 is set if
+ forms control has been inhibited on the I/O unit. Bit 11 is
+ set if the device handler can execute with the interrupt
+ system enabled. The data in bits 10 and 11 is obtained from
+ the IOWTBL table in the FRTS loader.
+
+ WORD 3: (BADFLD) Buffer address and field. Bits 0-4 address the
+ memory page at which the I/O buffer for this unit begins,
+ while bits 6-8 specify the memory field. Unlike the FORTRAN
+ internal I/O unit buffers, OS/8 device handler buffers always
+ occupy two full pages of memory. Buffer space is allocated
+ upward from the top of the FORTRAN program.
+
+ WORD 4: (CHRPTR) Character pointer.
+
+ WORD 5: (CHRCTR) Character counter. Words 4 and 5 of each DSRN table
+ entry define the current character/position in the I/O buffer
+ as follows:
+
+
+
+
+
+
+
+
+ 4-8
+\f
+
+
+ Value of Character Next value Next value Special
+ CHRCTR position of CHRCTR of CHRPTR Conditions
+ ----------------------------------------------------------------------
+ | Bits 4-11 of word | | | Refresh buffer if
+ -3 | addressed by | -2 | CHRPTR + 1 | input operation and
+ | CHRPTR | | | CHRPTR mod 256=0
+ | | | |
+ -2 | " | -1 | " | none
+ | | | |
+ -1 | Bits 0-3 of words | | |
+ | addressed by | | | Dump buffer if
+ | CHRPTR-2 and | -3 | CHRPTR | output operation
+ | CHRPTR-1 | | | and CHRPTR mod
+ | | | | 256=0
+ | | | |
+ ----------------------------------------------------------------------
+
+
+ WORD 6: (STBLK) Starting block of file.
+
+ WORD 7: (RELBLIC) Current relative block of file. That is, block to
+ be accessed next.
+
+ WORD 8: (TOTBLK) Length of file in blocks.
+
+ WORD 9: (FFLAGS) Status flags:
+
+ Bit 0 - Has been written flag. Set to 1 if unit has
+ received output since last REWIND.
+
+ Bit 1 - Formatted I/O flag. Set to 1 if an ASCII I/O
+ operation has occurred since last REWIND.
+
+ Bit 2 - Unformatted I/O flag. Set to 1 if a binary or
+ direct access I/O operation has occurred since last
+ REWIND. Bits 1 and 2 are never set simultaneously.
+
+ Bit 11- END FILEd flag. Set to 1 if unit has been END
+ FILEd. Bit 11 is not cleared by a REWIND.
+
+ When any active unit is selected for an I/O operation, the DSRN table
+ entry for that unit is moved into 9 words on page 0. These 9 words
+ are tagged with the labels cited above. Upon completion of the I/O
+ operation, the 9 words are moved from page 0 back into the DSRN table.
+
+
+
+
+
+
+
+
+
+
+
+ 4-9
+\f
+
+
+ /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 3
+
+ /PAGE ZERO FOR FORTRAN IV RTS
+
+ 0000 *0 /INTERRUPT STUFF
+ 00000 0000 0
+ 00001 5402 JMP I .+1
+ 00002 0400 INTRPT
+ 00003 5165 LPGET, LPBUFR /LINE PRINTER RING BUFFER FETCH
+ 00004 0000 TOCHR, 0 /TELETYPE STATUS WORD
+ 00005 0000 KBDCHR, 0 /KEYBOARD INPUT CHARACTER
+ 00006 0000 POCHR, 0 /P.T. PUNCH COMPLETION FLAG
+ 00007 0000 RDRCHR, 0 /P.T. READER STATUS
+ 00010 0000 FMTPXR, 0 /XR USED TO INDEX FORMAT PARENTH
+ 00011 3777 INXR, INBUFR-1 /XR USED TO GET CHARS FROM INPUT
+ 00012 0000 XR, 0
+ 00013 0000 XR1, 0
+
+ 0016 *16
+ 00016 0000 VEOFSW, 0 /USED BY "EOFCHK" TO STORE VARIABLE ADDRESS
+ 00017 0000 0 /*K* MUST BE IN AUTO - XR
+ 00020 0000 T, 0 /TEMPORARY
+ 00021 0000 DFLG, 0 /0 = F.P., 1 = D.P.
+ 00022 0000 INST, 0 /CURRENT INSTRUCTION WORD
+
+ /IOH PAGE ZERO LOCATIONS
+
+ 00023 0000 RWFLAG, 0 /READ/WRITE FLAG
+ 00024 0000 FMTTYP, 0 /TYPE OF CONVERSION BEING DONE
+ 00025 0000 EOLSW, 0 /EOL SW ON INPUT - CHAR POS ON OUT
+ 00026 0000 N, 0 /REPEAT FACTOR
+ 00027 0000 W, 0 /FIELD WIDTH
+ 00030 0000 D, 0 /NUMBER OF PLACES AFTER DECIMAL
+ 00031 0300 DATCDF, 0 /SUBROUTINE TO CHANGE DATA FIELD
+ 00032 0000 DATAF, 0 /CONTAINS VARIOUS CDF'S
+ 00033 5431 JMP I DATCDF /RETURN
+ 00034 5013 ERR, ERROR /POINTER TO ERROR ROUTINE
+ 00035 0000 FATAL, 0 /FATAL ERROR FLAG - 0=FATAL
+ 00036 5000 MCDF, MAKCDF
+
+ /FPP PARAMETER TABLE LOCATIONS:
+
+ 00037 0000 APT, 0 /VARIOUS FIELD BITS FOR FPP
+ 00040 5313 PC, DPTEST /FPP PROGRAM COUNTER
+ 00041 0000 XRBASE, 0 /FPP INDEX REGISTER ARRAY ADDRESS
+ 00042 0000 BASADR, 0 /FPP BASE PAGE ADDRESS
+ 00043 0000 ADR, 0 /ADDRESS TEMPORARY
+ 00044 0000 ACX, 0
+ 00045 0000 ACH, 0 /*** FLOATING ACCUMULATOR ***
+ 00046 0000 ACL, 0
+ 00047 0000 EAC1, 0
+ 00050 0000 EAC2, 0 /** FOR EXTENDED PRECISION OPTION **
+ 00051 0003 EAC3, 0
+
+
+ 4-10
+\f
+
+
+ /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 4
+
+ /FLOATING POINT PACKAGE LOCATIONS
+
+ 00052 0000 AC0, 0
+ 00053 0000 AC1, 0 /FLOATING AC OVERFLOW WORD
+ 00054 0000 AC2, 0 /OPERAND OVFLOW WORD
+ 00055 0000 OPX, 0
+ 00056 0000 OPH, 0 /*** FLOATING OPERAND REGISTER ***
+ 00057 0000 OPL, 0
+
+ /RTS I/O SYSTEM LOCATIONS
+
+ 00060 0000 FMTBYT, 0 /FORMAT BYTE POINTER
+ 00061 0000 IFLG, 0 /I FORMAT FLAG
+ 00062 0000 GFLG, 0 /G FORMAT FLAG
+ 00063 0000 EFLG, 0 /E FORMAT FLAG - SOMETIMES ON FOR
+ 00064 0000 OD, 0
+ 00065 0000 SCALE, 0
+ 00066 0000 PFACT, 0 /P-SCALE FACTOR
+ 00067 0000 PFACTX, 0 /TEMP FOR PFACT
+ 00070 0000 INESW, 0 /EXPONENT SWITCH
+ 00071 0000 CHCH, 0
+ 00072 0000 FMTNUM, 0 /CONTAINS ACCUMULATED NUMERIC VALUE
+ 00073 0000 CTCINH, 0 /^C INHIBIT FLAG
+ 00074 0320 PTTY, TTY /POINTER TO TTY HANDLER - USED BY
+ 00075 0000 0 / SO FORMS CONTROL WILL WORK ON
+ 00076 6001 FPNXT, ICYCLE /USED AS INTERPRETER ADDRESS IF
+
+ /DSRN IMAGE
+
+ 00077 0000 HAND, 0 /HANDLER ENTRY POINT
+ 00100 0000 HCODEW, 0 /HANDLER LOAD ADDR & FIELD + IOFFL
+ 00101 0000 BADFLD, 0 /BUFFER ADDRESS AND FIELD
+ 00102 0000 CHRPTR, 0 /ACTUALLY A WORD POINTER
+ 00103 0000 CHRCTR, 0 /COUNTER - RANGES FROM -3 TO -1
+ 00104 0000 STBLK, 0 /STARTING BLOCK OF FILE
+ 00105 0000 RELBLK, 0 /CURRENT RELATIVE BLOCK NUMBER
+ 00106 0000 TOTBLK, 0 /LENGTH OF FILE
+ 00107 0000 FFLAGS, 0 /FILE FLAGS:
+ /BIT 0 - "HAS BEEN WRITTEN" FLAG
+ /BITS 1-2 - FORMATTED/UNFORMATTED
+ /BIT 11 - "END-FILED" FLAG
+ 00110 0000 BUFFLD, 0 /ROUTINE TO SET DF TO BUFFER FIELD
+ 00111 7402 BUFCDF, HLT
+ 00112 5510 JMP I BUFFLD
+ 00113 0000 FGPBF, 0 /THESE THREE WORDS ARE USED
+ 00114 0000 BIOPTR, 0 /TO FETCH AND STORE FLOATING POINT
+ 00115 0000 FEXIT /FROM RANDOM MEMORY
+ 0200 PAGE
+
+
+
+
+
+ 4-11
+\f
+
+
+ /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 5
+
+ /STARTUP CODE
+
+ 00200 2203 FTEMP2, ISZ .+3 /ALSO USED AS I/O F.P. TEMPORARY
+ 00201 6213 CDF CIF 10
+ 00202 5603 JMP I .+1
+ 00203 2200 VDATE, RTSLDR /USED TO STORE OS/8 DATE
+
+ /RTS ENTRY POINTS - "VERSION INDEPENDENT"
+
+ 00204 5777 VUERR, JMP I (USRERR /USER ERROR
+ /** LOADER MUST DEFINE #ARGER AS
+ 00205 4434 VARGER, JMS I ERR /LIBRARY ARGUMENT ERROR
+ 00206 2023 VRENDO, ISZ RWFLAG /END OF I/O LIST
+ 00207 5634 VRFSV, JMP I GETLMN /I/O LIST ARG ENTRY - COROUTINE
+ 00210 5776 VBAK, JMP I (BKSPC /"BACKSPACE" ROUTINE
+ 00211 5775 VENDF, JMP I (ENDFL /"END FILE" ROUTINE
+ 00212 5774 VREW, JMP I (RWIND /"REWIND" ROUTINE
+ 00213 5773 VDEF, JMP I (DFINE /"DEFINE FILE" ROUTINE
+ 00214 7330 VWUO, AC4000 /UNFORMATTED WRITE
+ 00215 5772 VRUO, JMP I (RWUNF /UNFORMATTED READ
+ 00216 7330 VWDAO, AC4000 /DIRECT ACCESS WRITE
+ 00217 5771 VRDAO, JMP I (RWDACC /DIRECT ACCESS READ
+ 00220 7330 VWRITO, AC4000 /FORMATTED (ASCII) WRITE
+ 00221 5770 VREADO, JMP I (RWASCI /FORMATTED (ASCII) READ
+ 00222 5767 VSWAP, JMP I (SWAP /OVERLAY PROCESSOR
+ 00223 3000 VEXIT, TRAP3; CALXIT /"STOP" ROUTINE - ENTERED IN FPP
+ 00224 1317
+ 00225 0000 V8OR12, 0;0 /0;1 IF CPU IS A PDP-12
+ 00226 0000
+ 00227 5766 VBACKG, JMP I (NULLJB /BACKGROUND JOB DISPATCHER
+ 00230 0000 0
+ 00231 6203 CDF CIF 0 /USED BY ROUTINE "ONQB" IN LIBRARY
+ 00232 4630 JMS I .-2
+ 00233 5227 JMP VBACKG
+
+ /IOH GET VARIABLE ROUTINE.
+ /THIS ROUTINE MAKES THE FORMATTED I/O PROCESSOR AND THE
+ /PROGRAM CO-ROUTINES (DEF(COROUTINE): 2 ROUTINES EACH
+ / IS A SUBROUTINE). ON ENTRY FAC=INPUT NUMBER
+ /IF I/O IS A READ, ON RETURN FAC=OUTPUT NUMBER IF I/O
+
+ 00234 0000 GETLMN, 0
+ 00235 5577 VRETRN, JMP I [RETURN
+
+
+
+
+
+
+
+
+
+
+ 4-12
+\f
+
+
+ All FORTRAN IV mass storage I/O is performed in terms of OS/8 blocks,
+ including direct access I/O. Hence, all FORTRAN IV files conform to
+ OS/8 standard ASCII file format. When a formatted READ or WRITE is
+ requested, the data is converted to or from 8-bit binary representa-
+ tion according to the FORMAT statement associated with the READ or
+ WRITE. Standard OS/8 file format packs three 8-bit characters into
+ two 12-bit words as follows:
+
+ MASS STORAGE CORE
+ ----------------------------- ------------------
+ | WORD 3 | | | WORD 1 |
+ | bits 0-3 | WORD 1 | |----------------|
+ |---------------------------- | WORD 2 |
+ | WORD 3 | | |----------------|
+ | bits 4-7 | WORD 2 | | WORD 3 |
+ ----------------------------- ------------------
+
+ Unformatted (i.e. direct access) READ and WRITE operations also
+ operate on standard OS/8 format files, with each statement causing one
+ FORTRAN IV record to be read or written. A FORTRAN IV record must
+ contain at least one OS/8 block, and always contains an integral
+ number of blocks. The number of variables contained in a 1-block
+ record depends upon the content and format of the I/O list, as
+ follows:
+
+ Number of 12-bit Number of
+ Format type Words/Variable Variables/Block
+ ___________ ________________ _______________
+
+ Integer 3 85
+ Real 3 85
+ Double precision 6 42 1/2
+ Complex 6 42 1/2
+
+ It is possible to mix any types of data in an I/O list; however, no
+ more than 85 variables may be stored in one OS/8 block. The number of
+ blocks required for a FORTRAN IV record depends, therefore, upon the
+ number of variables in the I/O list, and may be minimized by supplying
+ every direct access WRITE with sufficient data to nearly fill an
+ integral number of blocks without overflowing the last block.
+
+ The last word in every file block contains a block count sequence
+ number and is not available for data storage. FRTS assigns block
+ count numbers sequentially, beginning with 1, whenever a file is
+ written. Block count numbers must be maintained by the user when
+ FORTRAN IV files are created outside of an OS/8 FORTRAN IV
+ environment. While reading a binary file, FRTS checks the block count
+ sequence numbers on input blocks and ignores any block whose sequence
+ number is larger than expected. Sequence number checking is disabled
+ during direct access READ operations.
+
+ When FRTS is loaded and started, the initialization routines deter-
+ mine what optional hardware, such as FPP-12 Floating Point Processor
+ or KE8E Extended Arithmetic Element, is present in the running
+ hardware configuration. The initialization routines then modify FRTS
+
+ 4-13
+\f
+
+
+ to use the optional hardware, if available. When an FPP is present in
+ the system and it becomes desirable to disable the FPP under FRTS,
+ this may be accomplished by changing the content of location 12621
+ from 6555 to 7200. The extended arithmetic element may be disabled in
+ the same manner by changing the content of FRTS location 12623 from
+ 7413 to 7200. These changes must be made before FRTS is started. The
+ OS/8 monitor GET and ODT commands provide an excellent mechanism for
+ changes of this type.
+
+ The FRTS internal line printer handler uses a linked ring buffer for
+ maximum I/O buffering efficiency. The buffer consists of several
+ contiguous sections of memory, linked together by pointers. All of
+ these buffer segments are located above 04000, so that the pointers
+ are readily distinguishable from buffered characters. The entire
+ 07400 page is included in the line printer ring buffer. If it becomes
+ desirable to modify FRTS by patching or reassembly, most of the 07400
+ page may be reclaimed from the buffer by changing the content of
+ location 07402 from 7577 to 5164. This frees up locations 07403 to
+ 07577 for new code and still leaves about eighty character positions
+ in the LPT ring buffer.
+
+ Because FRTS executes with the processor interrupt system enabled, it
+ may hang up on hardware configurations that include equipment capable
+ of generating spurious program interrupts. In addition, any OS/8 I/O
+ device handler that exits without clearing all device flags may cause
+ troublesome interrupts when it is assigned as a FORTRAN I/O unit under
+ FRTS. To counteract these potential problems, FRTS provides certain
+ areas that are reserved for inclusion of user-generated code designed
+ to clear device flags and/or inhibit spurious interrupts.
+
+ A string of NOP instructions beginning at location 04020 is executed
+ during FRTS initialization, just before the interrupt system is
+ enabled. When the /H option is specified to FRTS, the system halts
+ after these NOPs have been executed and the interrupt system has been
+ enabled. Another string of NOPs occupying the eight locations from
+ 03746 to 03755 is executed after every call to an OS/8 device handler.
+ Any of these NOP instructions may be replaced by flag-handling or
+ interrupt-servicing code. If additional memory locations are
+ required, they may be obtained by replacing some of the code from
+ locations 04007 to 04017 with flag-handling code. Locations 04007-17
+ are used to clear flags associated with LAB-8/E peripheral devices.
+
+ Due to memory limitations, it is not possible to add internal I/O
+ device handlers to the four internal handlers supplied with the
+ system. However, FORTRAN I/O unit 0, which is not defined by the ANSI
+ standard, may be specified for terminal I/O via the internal console
+ terminal handler. I/O unit 0 is not re-assignable.
+
+ The FRTS /P option provides a mechanism whereby the core image gener-
+ ated from a FORTRAN program may be punched onto paper tape in binary
+ loader format. This permits the loader image to be executed on a
+ hardware configuration that does not include mass-storage devices. To
+ use the /P option, specify /P to FRTS and assign a device or file as
+ FORTRAN I/O unit 9. Assigning the paper tape punch as unit 9 causes
+
+ 4-14
+\f
+
+
+ /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 6
+
+ /INTERRUPT DRIVEN I/O HANDLERS
+
+ 00236 0000 LPT, 0 /RING-BUFFERED - LP08 OR LS8E
+ 00237 0176 AND [377 /JUST IN CASE
+ 00240 7450 LPTSNA, SNA
+ 00241 5765 JMP I (IOERR /CANNOT BE USED FOR INPUT
+ 00242 6002 IOF
+ 00243 3667 DCA I LPPUT
+ 00244 1003 TAD LPGET
+ 00245 7041 CIA
+ 00246 1267 TAD LPPUT
+ 00247 7640 SZA CLA /IS LPT QUIET?
+ 00250 5253 JMP .+3 /NO
+ 00251 1667 TAD I LPPUT
+ 00252 6666 LLS /YES - START 'ER UP
+ 00253 7201 CLA IAC
+ 00254 6665 LIE /ENABLE LPT INTERRUPTS
+ 00255 1267 TAD LPPUT /1 IN AC, REMEMBER?
+ 00256 3267 DCA LPPUT
+ 00257 1667 TAD I LPPUT
+ 00260 7510 SPA
+ 00261 5256 JMP .-3 /NEGATIVE NUMBERS ARE BUFFER LINKS
+ 00262 7640 SZA CLA /ANY ROOM LEFT IN BUFFER?
+ 00263 4764 JMS I (HANG
+ 00264 0436 LPUHNG /WAIT FOR LINE PRINTER
+ 00265 6001 ION /TURN INTERRUPTS BACK ON
+ 00266 5636 JMP I LPT /RETURN
+
+ 00267 5165 LPPUT, LPBUFR
+
+ 00270 0000 PTP, 0 /PAPER TAPE PUNCH HANDLER
+ 00271 7450 SNA
+ 00272 5765 JMP I (IOERR /INPUT IS ERROR
+ 00273 3236 DCA LPT /SAVE CHAR
+ 00274 6002 IOF
+ 00275 1006 TAD POCHR /IF PUNCH IS NOT IDLE,
+ 00276 7640 SZA CLA /WE DISMISS JOB
+ 00277 4764 JMS I (HANG
+ 00300 0502 PPUHNG /WAIT FOR PUNCH INTERRUPT
+ 00301 1236 TAD LPT
+ 00302 6026 PLS /OUTPUT CHAR
+ 00303 3006 DCA POCHR /SET FLAG NON-ZERO
+ 00304 6001 ION
+ 00305 5670 JMP I PTP
+
+ /*K* THE FOLLOWING ADDRESSES GET FALLEN INTO & MUST BE SMALL
+
+ IFNZRO PPUHNG&7000 <--ERROR-->
+ IFNZRO TTUHNG&7000 <--ERROR-->
+ IFNZRO KBUHNG&7000 <--ERROR-->
+ IFNZRO RDUHNG&7000 <--ERROR-->
+ IFNZRO LPUHNG&7000 <--ERROR-->
+
+ 4-15
+\f
+
+
+ /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 7
+
+ /INTERRUPT-DRIVEN PTR AND TELETYPE HANDLER
+
+ 00306 0000 PTR, 0 /CRUDE READER HANDLER
+ 00307 7640 SZA CLA
+ 00310 5765 JMP I (IOERR /OUTPUT ILLEGAL TO PTR
+ 00311 6002 IOF
+ 00312 6014 RFC /START READER
+ 00313 4764 JMS I (HANG
+ 00314 0510 RDUHNG /HANG UNTIL COMPLETE
+ 00315 1007 TAD RDRCHR /GET CHARACTER
+ 00316 6001 ION
+ 00317 5706 JMP I PTR /RETURN
+ 00320 0000 TTY, 0 /BUFFERS 2 CHARS ON OUTPUT, 1 ON
+ 00321 6002 IOF /DELICATE CODE AHEAD
+ 00322 7450 SNA /INPUT OR OUTPUT?
+ 00323 5342 JMP KBD /INPUT
+ 00324 3236 DCA LPT /OUTPUT - SAVE CHAR
+ 00325 1004 TAD TOCHR /GET TTY STATUS
+ 00326 7740 SMA SZA CLA /G.T. 0 MEANS A CHAR IS BACKED UP
+ 00327 4764 JMS I (HANG
+ 00330 0451 TTUHNG /WAIT FOR LOG JAM TO CLEAR
+ 00331 1004 TAD TOCHR /NO CHAR BACKED UP - SEE IF TTY
+ 00332 7104 CLL RAL /"BUSY" FLAG IN LINK - INTERRUPTS
+ 00333 7230 CLA CML RAR /COMPLEMENT OF BUSY IN SIGN
+ 00334 1236 TAD LPT /GET CHAR
+ 00335 7510 SPA /IF TTY NOT BUSY,
+ 00336 6046 TLS /OUTPUT CHAR
+ 00337 3004 DCA TOCHR /STORE POS OR NEG, BACKED UP
+ 00340 6001 TTYRET, ION /TURN INTERRUPTS BACK ON
+ 00341 5720 JMP I TTY /AND LEAVE
+
+
+ /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 8
+
+ 00342 1005 KBD, TAD KBDCHR /HAS A CHARACTER BEEN INPUT?
+ 00343 7650 SNA CLA
+ 00344 4764 JMS I (HANG
+ 00345 0465 KBUHNG /NO - RUN BACKGROUND UNTIL ONE IS
+ 00346 1005 TAD KBDCHR /GET CHARACTER
+ 00347 3236 DCA LPT
+ 00350 3005 DCA KBDCHR /CHEAR CHARACTER BUFFER
+ 00351 1236 TAD LPT
+ 00352 5340 JMP TTYRET /RETURN WITH INTERRUPTS ON
+
+ 00353 6554 KILFPP, FPHLT /BRING FPP TO A SCREECHING HALT
+ 00354 2353 ISZ .-1
+ 00355 5354 JMP .-1 /WAIT FOR IT TO STOP
+ 00356 6552 FPICL /CLEAN UP MESS HALT HAS MADE IN FPP
+ 00357 7430 SZL /^C OR ^B?
+ 00360 5763 JMP I (7600 /^C - HIYO SILVER, AWAY!
+ 00361 6032 KCC /CLEAR KBD FLAG ON ^B
+ 00362 4434 CTLBER, JMS I ERR /*** THIS MAY BE DANGEROUS! **
+
+ 4-16
+\f
+
+
+ /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 9
+
+ /INTERRUPT SERVICE ROUTINES
+
+ 00400 3322 INTRPT, DCA INTAC
+ 00401 7010 RAR
+ 00402 3323 DCA INTLNK
+ 00403 5207 VINT, JMP .+4 /** MUST BE AT 403 **
+ IFNZRO VINT-403 <--- CHANGE LOADER!!!>
+ 00404 0000 0
+ 00405 6203 CDF CIF 0 /USER INTERRUPT ROUTINE GOES HERE
+ 00406 4604 JMS I .-2
+
+ 00407 6551 FPINT /CHECK FOR FPP DONE
+ 00410 5215 JMP LPTEST
+ 00411 5314 FPUHNG, JMP DISMIS /ALWAYS GOES TO RESTRT
+
+ 00412 5314 VDISMS, JMP DISMIS /FOR USE BY USERS
+ 00413 5314 JMP DISMIS
+ 00414 5314 JMP DISMIS
+ 00415 6661 LPTEST, LSF
+ 00416 5240 JMP NOTLPT
+ 00417 6662 LPTLCF, LCF /CLEAR FLAG
+ 00420 1403 TAD I LPGET
+ 00421 7650 SNA CLA /CHECK FOR SPURIOUS INTERRUPT
+ 00422 5314 JMPDIS, JMP DISMIS /GO AWAY IF SO
+ 00423 3403 DCA I LPGET /ZERO CHAR JUST OUTPUT
+ 00424 2003 ISZ LPGET
+ 00425 1403 TAD I LPGET
+ 00426 7510 SPA
+ 00427 3003 DCA LPGET /TAKE CARE OF BUFFER LINKS
+ 00430 7450 SNA
+ 00431 1403 TAD I LPGET /HAKE SURE CHAR IS IN AC
+ 00432 7440 SZA /IS THERE A CHARACTER?
+ 00433 6666 LLS /YES - PRINT IT
+ 00434 7200 CLA
+ 00435 6661 LSF /CHECK FOR IMMEDIATE FLAG
+ 00436 5314 LPUHNG, JMP DISMIS /NO - MAYBE RESTART PROGRAM
+ 00437 5217 JMP LPTLCF /YES - LOOP
+
+ 00440 6041 NOTLPT, TSF /CHECK TTY
+ 00441 5252 JMP NOTTTY
+ 00442 6042 TCF /CLEAR FLAG
+ 00443 1004 TAD TOCHR /GET TTY STATUS
+ 00444 7540 SMA SZA /IF THERE IS A CHARACTER WAITING,
+ 00445 6046 TLS /OUTPUT IT.
+ 00446 7740 SMA SZA CLA /CHANGE "WAITING" TO "BUSY",
+ 00447 7130 STL RAR /"BUSY" TO "IDLE".
+ 00450 3004 DCA TOCHR
+ 00451 5314 TTUHNG, JMP DISMIS
+
+
+
+
+
+ 4-17
+\f
+
+
+ /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 10
+
+ /KBD AND PTP INTERRUPTS
+
+ 00452 6031 NOTTTY, KSF
+ 00453 5276 JMP NOTKBD
+ 00454 1175 TAD [200
+ 00455 6034 KRS /USE KRS TO FORCE PARITY BIT
+ 00456 3005 DCA KBDCHR /AND ALSO SO THAT ^C WILL STILL
+ 00457 1005 TAD KBDCHR
+ 03460 1377 TAD (-202 /CHECK FOR ^C OR ^B
+ 00461 7110 CLL RAR
+ 00462 7650 SNA CLA
+ 00463 5266 JMP CTCCTB /YUP - TAKE SOME DRASTIC ACTION
+ 00464 6032 KCC /DATA CHARACTER - CLEAR FLAG
+ 00465 5314 KBUHNG, JMP DISMIS
+
+ 00466 1073 CTCCTB, TAD CTCINH
+ 00467 7650 SNA CLA /ARE WE IN A HANDLER?
+ 00470 5366 JMP NOTINH /NO
+ 00471 1323 TAD INTLNK
+ 00472 7104 CLL RAL /YES - RETURN WITH INTERRUPTS OFF
+ 00473 1322 TAD INTAC /TRUST IN GOD AND RTS
+ 00474 6244 RMF
+ 00475 5400 JMP I 0
+
+ 00476 6021 NOTKBD, PSF
+ 00477 5303 JMP NOTPTP
+ 00500 6022 PCF /P.T. PUNCH INTERRUPT - CLEAR FLAG
+ 00501 3006 DCA POCHR /CLEAR SOFTWARE FLAG
+ 00502 5314 PPUHNG, JMP DISMIS
+
+ 00503 6011 NOTPTP, RSF
+ 00504 5311 JMP LPTERR
+ 00505 1175 TAD [200
+ 00506 6012 RRB /GET RDR CHAR
+ 00507 3007 DCA RDRCHR
+ 00510 5314 RDUHNG, JMP DISMIS
+
+ 00511 6663 LPTERR, LSE /TEST FOR LP08 ERROR FLAG
+ 00512 7410 SKP
+ 00513 6667 LIF /DISABLE LP08 INTERRUPTS IF ERROR
+ 00514 1323 DISMIS, TAD INTLNK
+ 00515 7104 CLL RAL
+ 00516 1322 TAD INTAC /RESTORE AC AND LINK
+ 00517 6244 RMF
+ 00520 6001 ION
+ 00521 5400 JMP I 0 /RETURN FROM THE INTERRUPT
+
+ 00522 0000 INTAC, 0
+ 00523 0000 INTLNK, 0
+
+
+
+
+ 4-18
+\f
+
+
+ /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 11
+
+ /BACKGROUND INITIATE/TERMINATE ROUTINE
+
+ 00524 0000 HANG, 0 /ALWAYS CALLED WITH INTERRUPTS OFF!
+ 00525 1724 TAD I HANG /GET POINTER TO UNHANGING LOCATION
+ 00526 3371 DCA UNHANG
+ 00527 6214 RDF /GET FIELD CALLED FROM
+ 00530 1332 TAD HCIDF0
+ 00531 3364 DCA HNGCDF /SAVE FOR RETURN
+ 00532 6203 HCIDF0, CDF CIF 0
+ 00533 1376 TAD (JMP RESTRT /CHANGE THE "JMP DISMIS"
+ 00534 3771 DCA I UNHANG /TO A "JMP RESTRT"
+ 00535 1373 TAD BACKLK
+ 00536 7104 CLL RAL
+ 00537 1372 TAD BACKAC /SET UP BACKGROUND AC AND LINK
+ 00540 6202 BAKCIF, CIF 0
+ 00541 6201 BAKCDF, CDF 0
+ 00542 6001 ION
+ 00543 5774 JMP I BACKPC /INITIATE BACKGROUND
+
+ / COME HERE WHEN THE HANG CONDITION HAS GONE AWAY
+
+ 00544 1222 RESTRT, TAD JMPDIS /RESTORE THE UNHANG LOCATION
+ 00545 3771 DCA I UNHANG
+ 00546 1322 TAD INTAC /SUSPEND THE BACKGROUND
+ 00547 3372 DCA BACKAC
+ 00550 1323 TAD INTLNK
+ 00551 3373 DCA BACKLK
+ 00552 1000 TAD 0
+ 00553 3374 DCA BACKPC
+ 00554 6234 RIB
+ 00555 0174 AND [70
+ 00556 1332 TAD HCIDF0
+ 00557 3340 DCA BAKCIF
+ 00560 6234 RIB
+ 00561 4436 JMS I MCDF /*K* OK SINCE BACKGROUND DOESN'T
+ 00562 3341 DCA BAKCDF
+ 00563 2324 ISZ HANG
+ 00564 7402 HNGCDF, HLT
+ 00565 5724 JMP I HANG /INTERRUPTS ARE OFF - RETURN
+ 00566 1222 NOTINH, TAD JMPDIS /IN CASE WE WERE HUNG, WE DON'T
+ 00567 3771 DCA I UNHANG /TO GET "UNHUNG" OUT OF THE ERROR
+ 00570 5775 JMP I (KILFPP /KILL FPP AND GO TO EXIT OR ERROR
+
+ 00571 0000 UNHANG, 0
+ 00572 0000 BACKAC, 0
+ 00573 0000 BACKLK, 0
+ 00574 0227 BACKPC, VBACKG
+ 0524 VHANG= HANG
+ IFNZRO VHANG-0524 <--CHANGE LOADER!>
+ 00575 0353
+ 00576 5344
+ 00577 7576
+ 0600 PAGE
+ 4-19
+\f
+
+
+ the image to be punched out directly; however, it may be desirable to
+ direct the binary output to an intermediate file for later transfer to
+ paper tape via OS/8 PIP. In any event, FRTS returns to the monitor
+ once the core image has been transferred.
+
+ The output file is a binary image of memory locations 00000 to 07577
+ and 10000 up to the highest location used by the FORTRAN load. The
+ content of each field is punched separately with its own checksum and
+ leader/trailer.
+
+ With the BIN loader resident in field 0, load the binary tape produced
+ under the /P option by reading each segment separately and verifying
+ the checksum as each memory field is loaded. When all segments have
+ been read into memory, start execution at location 00200. The
+ following restrictions apply:
+
+ 1. OS/8 device handlers which have been assigned FORTRAN I/O
+ unit numbers are not necessarily punched out. For this
+ reason, I/O unit assignments other than in the form /n=m
+ should be avoided.
+
+ 2. With respect to the presence of an FPP and/or EAE, the con-
+ figuration on which the image is punched must be identical to
+ the configuration on which it is to be run. If the punching
+ configuration contains hardware that is absent from the
+ target configuration, this hardware must be disabled under
+ FRTS. If the target configuration contains hardware that is
+ absent from the punching configuration, the extraneous
+ hardware will not be used.
+
+ 3. The statements STOP and CALL EXIT cause a core load produced
+ under the /P option to halt. Any fatal error flagged during
+ punching or execution causes error traceback followed by a
+ halt. Do not press CONTinue in response to either of these
+ machine halts.
+
+ A FORTRAN IV program is terminated in one of three ways:
+
+ 1. A fatal error condition is flagged (CTRL/B) is processed as a
+ fatal error.
+
+ 2. CTRL/C is recognized, or the CPU is halted and re-started in
+ 07600.
+
+ 3. A STOP, CALL EXIT, or (under RALF) JSR #EXIT statement is
+ executed.
+
+ The sequence of events that results in program termination proceeds as
+ follows:
+
+
+
+
+
+
+ 4-20
+\f
+
+
+ Fatal Error STOP
+ (1) (CTRL/B) (2) CTRL/C CALL EXIT (3)
+ | | JSR #EXIT |
+ ------------- --------------- ---------------
+ | BRANCH TO | | | | SIMULATE |
+ | ERROR | | EXECUTE IOF | | END FILE ON |
+ | ROUTINE | | | | ANY OPEN |
+ ------------- --------------- | FILES |
+ | | ---------------
+ | | |<-------
+ ------------- --------------- / \ |
+ | | | LET I/O DE- | / TTY, \ |
+ | PRINT | | VICE HANDLER| /LPT BUFFERS\_|
+ | TRACEBACK | | PROCESS ^C | \ CLEAR / NO
+ ------------- --------------- \ ? /
+ | | \ /
+ | | | YES
+ | | |
+ | ------------- | ---------------
+ | | | | | SET NORMAL |
+ ----->| JMP 07605 |<------ | TERMINATION |
+ | | | FLAG |
+ ------------- ---------------
+ | |
+ | Location 07605 traps back to FRTS |
+ -------------------------------------|
+ (A)
+
+
+
+ At point A, FRTS executes the following operations.
+
+ 1. Read termination routine into memory.
+
+ 2. Read OS/8 field 0 resident from block 37 of SYS.
+
+ 3. Jump into termination routine at location 17400.
+
+ 4. restore normal content of locations 07600 and 07605 (in OS/8
+ resident).
+
+ 5. If configuration is an in-core TD8E DECtape system, restore
+ second part of TD8E handler from n7600 to 27600.
+
+ 6. Wait for TTY to finish all pending I/O. If BATCH is running,
+ print LF on TTY and LPT.
+
+ 7. If normal termination flag is set, close any output files
+ that were opened by the FRTS loader.
+
+ 8. Return to OS/8 monitor via location 07605.
+
+
+
+
+ 4-21
+\f
+
+
+ /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 78
+
+ 6600 FPPKG= . /FOR EAE OVERLAY
+
+ /23-BIT FLOATING PT INTERPRETER
+ /W.J. CLOGHER, MODIFIED BY R.LARY FOR FORTRAN
+
+ 06600 0000 LPBUF2, ZBLOCK 16
+ 06616 7160 LPBUF3
+
+ 06617 0000 AL1BMP, 0 /*K* UTILITY SUBROUTINE
+ 06620 7240 STA
+ 06621 1044 TAD ACX
+ 06622 3044 DCA ACX
+ 06623 4542 JMS I [AL1
+ 06624 5617 JMP I AL1BMP
+
+ /FLOATING MULTIPLY-DOES 2 24X12 BIT MULTIPLIES
+ 06625 4777 DDMPY, JMS I (DARGET
+ 06626 7410 SKP
+ 06627 4776 FFMPY, JMS I (ARGET /GET OPERAND
+ 06630 4304 JMS MDSET /SET UP FOR MPY-OPX IN AC ON RETN.
+ 06631 1044 TAD ACX /DO EXPONENT ADDITION
+ 06632 3044 DCA ACX /STORE FINAL EXPONENT
+ 06633 3304 DCA MDSET /ZERO TEM STORAGE FOR MPY ROUTINE
+ 06634 3054 DCA AC2
+ 06635 1045 TAD ACH /IS FAC=0?
+ 06636 7650 SNA CLA
+ 06637 3044 DCA ACX /YES-ZERO EXPONENT
+ 06640 4334 JMS MP24 /NO-MULTIPLY FAC BY LOW ORDER OPR.
+ 06641 1056 TAD OPH /NOW MULTIPLY FAC BY HI ORDER MULT
+ 06642 3057 DCA OPL
+ 06643 4334 JMS MP24
+ 06644 1054 TAD AC2 /STORE RESULT BACK IN FAC
+ 06645 3046 DCA ACL /LOW ORDER
+ 06646 1304 TAD MDSET /HIGH ORDER
+ 06647 3045 DCA ACH
+ 06650 1045 TAD ACH /DO WE NEED TO NORMALIZE?
+ 06651 7004 RAL
+ 06652 7710 SPA CLA
+ 06653 4217 JMS AL1BMP /YES-DO IT FAST
+ 06654 1053 TAD AC1
+ 06655 7710 SPA CLA /CHECK OVERFLOW WORD
+ 06656 2046 ISZ ACL /HIGH BIT ON - ROUND RESULT
+ 06657 5265 JMP MDONE
+ 06660 2045 ISZ ACH /LOW ORDER OVERFLOWED - INCREMENT
+ 06661 1045 TAD ACH
+ 06662 7510 SPA /CHECK FOR OVERFLOW TO 4000 0000
+ 06663 5775 JMP I (SHR1 /WE HANDLE A SIMILIAR CASE IN
+ 06664 7200 CLA
+
+
+
+
+
+ 4-22
+\f
+
+
+ /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 79
+
+ 06665 3053 MDONE, DCA AC1 /ZERO OVERFLOW WD(DO I NEED THIS???
+ 06666 2333 ISZ MSIGN /SHOULD RESULT BE NEGATIVE?
+ 06667 7410 SKP /NO
+ 06670 4543 JMS I [FFNEG /YES-NEGATE IT
+ 06671 1045 TAD ACH
+ 06672 7650 SNA CLA /A ZERO AC MEANS A ZERO EXPONENT
+ 06673 3044 DCA ACX
+ 06674 1021 TAD DFLG
+ 06675 7740 SMA SZA CLA /D.P. INTEGER MODE?
+ 06676 1044 TAD ACX /WITH ACX LESS THAN 0?
+ 06677 7450 SNA
+ 06700 5476 JMP I FPNXT /NO - RETURN
+ 06701 7040 CMA
+ 06702 4541 JMS I [ACSR /UN-NORMALIZE RESULT
+ 06703 5476 JMP I FPNXT /RETURN
+
+
+
+
+ /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 80
+
+ /MDSET-SETS UP SIGNS FOR MULTIPLY AND DIVIDE
+ /ALSO SHIFTS OPERAND ONE BIT TO THE LEFT.
+ /EXIT WITH EXPONENT OF OPERAND IN AC FOR EXPONENT
+ /CALCULATION-CALLED WITH ADDRESS OF OPERAND IN AC AND
+ /DATA FIELD SET PROPERLY FOR OPERAND.
+
+ 06704 0000 MDSET, 0
+ 06705 7344 CLA CLL CMA RAL /SET SIGN CHECK TO -2
+ 06706 3333 DCA MSIGN
+ 06707 1056 TAD OPH /IS OPERAND NEGATIVE?
+ 06710 7700 SMA CLA
+ 06711 5314 JMP .+3 /NO
+ 06712 4774 JMS I (OPNEG /YES-NEGATE IT
+ 06713 2333 ISZ MSIGN /BUMP SIGN CHECK
+ 06714 1057 TAD OPL /AND SHIFT OPERAND LEFT ONE BIT
+ 06715 7104 CLL RAL
+ 06716 3057 DCA OPL
+ 06717 1056 TAD OPH
+ 06720 7004 RAL
+ 06721 3056 DCA OPH
+ 06722 3053 DCA AC1 /CLR. OVERFLOW WORD OF FAC
+ 06723 1045 TAD ACH /IS FAC NEGATIVE
+ 06724 7700 SMA CLA
+ 06725 5331 JMP LEV /NO-GO ON
+ 06726 4543 JMS I [FFNEG /YES-NEGATE IT
+ 06727 2333 ISZ MSIGN /BUMP SIGN CHECK
+ 06730 7000 NOP /MAY SKIP
+ 06731 1055 LEV, TAD OPX /EXIT WITH OPERAND EXPONENT IN AC
+ 06732 5704 JMP I MDSET
+ 06733 0000 MSIGN, 0
+
+
+ 4-23
+\f
+
+
+ /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 81
+
+ /24 BIT BY 12 BIT MULTIPLY. MULTIPLIER IS IN OPL
+ /MULTIPLICAND IS IN ACH AND ACL
+ /RESULT LEFT IN MDSET,AC2, AND AC1
+
+ 06734 0000 MP24, 0
+ 06735 1373 TAD (-14 /SET UP 12 BIT COUNTER
+ 06736 3055 DCA OPX
+ 06737 1057 TAD OPL /IS MULTIPLIER=0?
+ 06740 7440 SZA
+ 06741 5345 JMP MPLP1 /NO-GO ON
+ 06742 3053 DCA AC1 /YES-INSURE RESULT=0
+ 06743 5734 JMP I MP24 /RETURN
+ 06744 1057 MPLP, TAD OPL /SHIFT A BIT OUT OF LOW ORDER
+ 06745 7010 MPLP1, RAR /OF MULTIPLIER AND INTO LINK
+ 06746 3057 DCA OPL
+ 06747 7420 SNL /WAS IT A 1?
+ 06750 5356 JMP MPLP2 /NO - 0 - JUST SHIFT PARTIAL PROD
+ 06751 1054 TAD AC2 /YES-ADD MULTIPLICAND TO PARTIAL
+ 06752 1046 TAD ACL /LOW ORDER
+ 06753 3054 DCA AC2
+ 06754 7024 CML RAL /*K* NOTE THE "SNL" 5 WORDS BACK!
+ 06755 1045 TAD ACH /HI ORDER
+ 06756 1304 MPLP2, TAD MDSET
+ 06757 7010 RAR /NOW SHIFT PARTIAL PROD. RIGHT 1
+ 06760 3304 DCA MDSET
+ 06761 1054 TAD AC2
+ 06762 7010 RAR
+ 06763 3054 DCA AC2
+ 06764 1053 TAD AC1
+ 06765 7010 RAR /OVERFLOW TO AC1
+ 06766 3053 DCA AC1
+ 06767 2055 ISZ OPX /DONE ALL 12 MULTIPLIER BITS?
+ 06770 5344 JMP MPLP /NO-GO ON
+ 06771 5734 JMP I MP24 /YES-RETURN
+ 06773 7764
+ 06774 7203
+ 06775 7110
+ 06776 6514
+ 06777 6460
+ 7000 PAGE
+
+
+ /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 82
+
+ /DIVIDE-BY-ZERO ROUTINE - MUST BE AT BEGINNING Of PAGE
+
+ 07000 2035 DBAD, ISZ FATAL /DIVIDE BY 0 NON-FATAL
+ 07001 4434 JMS I ERR /GIVE ERROR MSG
+ 07002 1200 TAD DBAD
+ 07003 3044 DCA ACX /RETURN A VERY LARGE POSITIVE NUM
+ 07004 7332 AC2000
+ 07005 5325 JMP FD
+
+ 4-24
+\f
+
+
+ /FLOATING DIVIDE - USES DIVIDE-AND-CORRECT METHOD
+
+ 07006 4777 DDDIV, JMS I (DARGET
+ 07007 7410 SKP
+ 07010 4776 FFDIV, JMS I (ARGET /GET OPERAND
+ 07011 4775 JMS I (MDSET /GO SET UP FOR DIVIDE-OPX IN AC
+ 07012 7041 CMA IAC /NEGATE EXP. OF OPERAND
+ 07013 1044 TAD ACX /ADD EXP OF FAC
+ 07014 3044 DCA ACX /STORE AS FINAL EXPONENT
+ 07015 1056 TAD OPH /NEGATE HI ORDER OP. FOR USE
+ 07016 7141 CLL CMA IAC /AS DIVISOR
+ 07017 3056 DCA OPH
+ 07020 4231 JMS DV24 /CALL DIV.--(ACH+ACL)/OPH
+ 07021 1046 TAD ACL /SAVE QUOT. FOR LATER
+ 07022 3053 DCA AC1
+ 07023 1057 TAD OPL
+ 07024 7650 SNA CLA
+ 07025 5327 JMP DVL2 /AVOID MULTIPLYING BY 0
+ 07026 1374 TAD (-15 /SET COUNTER FOR 12 BIT MULTIPLY
+ 07027 3231 DCA DV24 /TO MULTIPLY QUOT. OF DIV. BY
+ 07030 5267 JMP DVLP1 /LOW ORDER OF OPERAND (OPL)
+
+ /DIVIDE ROUTINE - (ACH,ACL)/OPH = ACL REMAINDER REM
+
+ 07031 0000 DV24, 0
+ 07032 1045 TAD ACH /CHECK THAI DIVISOR IS .GT.
+ 07033 1056 TAD OPH /DIVISOR IN OPH (NEGATIVE)
+ 07034 7630 SZL CLA /IS IT?
+ 07035 5200 JMP DBAD /NO-DIVIDE OVERFLOW
+ 07036 1374 TAD (-15 /YES-SET UP 12 BIT LOOP
+ 07037 3054 DCA AC2
+ 07040 5251 JMP DV1 /GO BEGIN DIVIDE
+ 07041 1045 DV2, TAD ACH /CONTINUE SHIFT OF FAC LEFT
+ 07042 7004 RAL
+ 07043 3045 DCA ACH /RESTORE HI ORDER
+ 07044 1045 TAD ACH /NOW SUBTRACT DIVISOR FROM HI ORDER
+ 07045 1056 TAD OPH /DIVIDEND
+ 07046 7430 SZL /GOOD SUBTRACT?
+ 07047 3045 DCA ACH /YES-RESTORE HI DIVIDEND
+ 07050 7200 CLA /NO-DON'T RESTORE--OPH.GT.ACH
+ 07051 1046 DV1, TAD ACL /SHIFT FAC LEFT 1 BIT-ALSO SHIFT
+ 07052 7004 RAL /1 BIT OF QUOT. INTO LOW ORD OF ACL
+ 07053 3046 DCA ACL
+ 07054 2054 ISZ AC2 /DONE 12 BITS OF QUOT?
+ 07055 5241 JMP DV2 /NO-GO ON
+ 07056 5631 JMP I DV24 /YES-RETN W/AC2=0
+
+
+
+
+
+
+
+
+
+ 4-25
+\f
+
+
+ /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 83
+
+ /DIVIDE ROUTINE CONTINUED
+
+ 07057 3057 MP12L, DCA OPL /STORE BACK MULTIPLIET
+ 07060 1054 TAD AC2 /GET PRODUCT SO FAR
+ 07061 7420 SNL /WAS MULTIPLIER BIT A 1?
+ 07062 5265 JMP .+3 /NO-JUST SHIFT THE PARTIAL PRODUCT
+ 07063 7100 CLL /YES-CLEAR LINK AND ADD MULTIPLICAND
+ 07064 1046 TAD ACL /TO PARTIAL PRODUCT
+ 07065 7010 RAR /SHIFT PARTIAL PRODUCT-THIS IS HI
+ 07066 3054 DCA AC2 /RESULT-STORE BACK
+ 07067 1057 DVLP1, TAD OPL /SHIFT A BIT OUT OF MULTIPLIER
+ 07070 7010 RAR /AND A BIT OR RESLT. INTO IT (LO
+ 07071 2231 ISZ DV24 /DONE ALL BITS?
+ 07072 5257 JMP MP12L /NO-LOOP BACK
+ 07073 7141 CLL CIA /YES-LOW ORDER PROD. OF QUOT. X
+ 07074 3046 DCA ACL /NEGATE AND STORE
+ 07075 7024 CML RAL /PROPAGATE CARRY
+ 07076 1054 TAD AC2 /NEGATE HI ORDER PRODUCT
+ 07077 7161 STL CIA
+ 07100 1045 TAD ACH /COMPARE WITH REMAINDER OF FIRST
+ 07101 7430 SZL /WELL?
+ 07102 5331 JMP DVOPS /GREATER THAN REM. - ADJUST QUOT OF
+ 07103 3045 DCA ACH /OK - DO (REM - (Q*OPL)) / OPH
+ 07104 4231 DVL3, JMS DV24 /DIVIDE BY OPH (HI ORDER OPERAND)
+ 07105 1053 DVL1, TAD AC1 /GET QUOT. OF FIRST DIV.
+ 07106 7500 SMA /IF HI ORDER BIT SET-MUST SHIFT 1
+ 07107 5325 JMP FD /NO-ITS NORMALIZED-DONE
+ 07110 7100 SHR1, CLL
+ 07111 2046 ISZ ACL /ROUND AND SHIFT RIGHT ONE
+ 07112 7410 SKP
+ 07113 7001 IAC /DOUBLE PRECISION INCREMENT
+ 07114 7010 RAR
+ 07115 3045 DCA ACH /STORE IN FAC
+ 07116 1046 TAD ACL /SHIFT LOW ORDER RIGHT
+ 07117 7010 RAR
+ 07120 3046 DCA ACL /STORE BACK
+ 07121 2044 ISZ ACX /BUMP EXPONENT
+ 07122 7000 NOP
+ 07123 1045 TAD ACH
+ 07124 5306 JMP DVL1+1 /IF FRACT WAS 77777777 WE MUST
+ 07125 3045 FD, DCA ACH /STORE HIGH ORDER RESULT
+ 07126 5773 JMP I (MDONE /GO LEAVE DIVIDE
+
+ 07127 3046 DVL2, DCA ACL /COME HERE IF LOW-ORDER QUO=0
+ 07130 5304 JMP DVL3 /SAVE SOME TIME
+
+
+
+
+
+
+
+
+ 4-26
+\f
+
+
+ /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 84
+
+ /ROUTINE TO ADJUST QUOTIENT OF FIRST DIVIDE (MAYBE) WHEN
+ /REMAINDER OF THE FIRST DIVIDE IS LESS THAN QUOT*OPL
+
+ 07131 7041 DVOPS, CMA IAC /NEGATE AND STORE REVISED REMAINDER
+ 07132 3045 DCA ACH
+ 07133 7100 CLL
+ 07134 1056 TAD OPH
+ 07135 1045 TAD ACH /WATCH FOR OVERFLOW
+ 07136 7420 SNL
+ 07137 5344 JMP DVOP1 /OVERFLOW-DON'T ADJUST QUOT. OF 1
+ 07140 3045 DCA ACH /NO OVERFLOW-STORE NEW REM.
+ 07141 7040 CMA /SUBTRACT 1 FROM QUOT OF
+ 07142 1053 TAD AC1 /FIRST DIVIDE
+ 07143 3053 DCA AC1
+ 07144 7300 DVOP1, CLA CLL
+ 07145 1045 TAD ACH /GET HI ORD OF REMAINDER
+ 07146 7450 SNA /IS IT ZERO?
+ 07147 3046 DVOP2, DCA ACL /YES-MAKE WHOLE THING ZERO
+ 07150 3045 DCA ACH
+ 07151 4231 JMS DV24 /DIVIDE EXTENDED REM. BY HI DIVISOR
+ 07152 1046 TAD ACL /NEGATE THE RESULT
+ 07153 7141 CLL CMA IAC
+ 07154 3046 DCA ACL
+ 07155 7420 SNL /IF QUOT. IS NON-ZERO, SUBTRACT
+ 07156 7040 CMA /ONE FROM HIGH ORDER QUOT.
+ 07157 5305 JMP DVL1 /GO TO IT
+
+ 07160 0000 LPBUF3, ZBLOCK 12
+ 07172 7316 LPBUF4
+ 07173 6665
+ 07174 7763
+ 07175 6704
+ 07176 6514
+ 07177 6460
+ 7200 PAGE
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ 4-27
+\f
+
+
+ /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 85
+
+ /"NRMFAC" AND "OPNEG" MUST BE AT 0 AND 3 ON PAGE
+
+ 07200 3053 NRMFAC, DCA AC1 /KILL OVERFLOW BIT
+ 07201 4271 JMS FFNOR
+ 07202 5476 JMP I FPNXT
+
+ 07203 0000 OPNEG, 0 /ROUTINE TO NEGATE OPERAND
+ 07204 1057 TAD OPL /GET LOW ORDER
+ 07205 7141 CLL CMA IAC /NEGATE AND STORE BACK
+ 07206 3057 DCA OPL
+ 07207 7024 CML RAL /PROPAGATE CARRY
+ 07210 1056 TAD OPH /GET HI ORDER
+ 07211 7141 CLL CMA IAC /NEGATE AND STORE BACK
+ 07212 3056 DCA OPH
+ 07213 5603 JMP I OPNEG
+ /
+ /FLOATING SUBTRACT AND ADD
+ /
+ 07214 4777 FFSUB, JMS I (ARGET /PICK UP THE OP.
+ 07215 4203 JMS OPNEG /NEGATE OPERAND
+ 07216 7410 SKP
+ 07217 4777 FFADD, JMS I (ARGET /PICK UP OPERAND
+ 07220 1056 TAD OPH /IS OPERAND = 0
+ 07221 7650 SNA CLA
+ 07222 5476 JMP I FPNXT /YES-DONE
+ 07223 1045 TAD ACH /NO-IS FAC=0?
+ 07224 7650 SNA CLA
+ 07225 5236 JMP DOADD /YES-DO ADD
+ 07226 1044 TAD ACX /NO-DO EXPONENT CALCULATION
+ 07227 7141 CLL CMA IAC
+ 07230 1055 TAD OPX
+ 07231 7540 SMA SZA /WHICH EXP. GREATER?
+ 07232 5243 JMP FACR /OPERANDS-SHIFT FAC
+ 07233 7041 CMA IAC /FAC'S-SHIFT OPERAND=DIFFRNCE+1
+ 07234 4246 JMS OPSR
+ 07235 4541 JMS I [ACSR /SHIFT FAC ONE PLACE RIGHT
+ 07236 1055 DOADD, TAD OPX /SET EXPONENT OF RESULT
+ 07237 3044 DCA ACX
+ 07240 4537 JMS I [OADD /DO THE ADDITION
+ 07241 4271 JMS FFNOR /NORMALIZE RESULT
+ 07242 5476 JMP I FPNXT /RETURN
+ 07243 4541 FACR, JMS I [ACSR /SHIFT FAC = DIFF.+1
+ 07244 4246 JMS OPSR /SHIFT OPR. 1 PLACE
+ 07245 5236 JMP DOADD /DO ADDITION
+
+
+
+
+
+
+
+
+
+ 4-28
+\f
+
+
+ /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 86
+
+ /OPERAND SHIFT RIGHT-ENTER WITH POSITIVE COUNT-1 IN AC
+
+ 07246 0000 OPSR, 0
+ 07247 7040 CMA /- (COUNT+1) TO SHIFT COUNTER
+ 07250 3052 DCA AC0
+ 07251 1056 LOP2, TAD OPH /GET SIGN BIT
+ 07252 7100 CLL /TO LINK
+ 07253 7510 SPA
+ 07254 7020 CML /WITH HI MANTISSA IN AC
+ 07255 7010 RAR /SHIFT IT RIGHT, PROPAGATING SIGN
+ 07256 3056 DCA OPH /STORE BACK
+ 07257 1057 TAD OPL
+ 07260 7010 RAR
+ 07261 3057 DCA OPL /STORE LO ORDER BACK
+ 07262 2055 ISZ OPX /INCREMENT EXPONENT
+ 07263 7000 NOP
+ 07264 2052 ISZ AC0 /DONE ALL SHIFTS?
+ 07265 5251 JMP LOP2 /NO-LOOP
+ 07266 7010 RAR /SAVE 1 BIT OF OVERFLOW
+ 07267 3054 DCA AC2 /IN AC2
+ 07270 5646 JMP I OPSR /YES-RETN.
+
+ 07271 0000 FFNOR, 0 /ROUTINE TO NORMALIZE THE FAC
+ 07272 1045 TAD ACH /GET THE HI ORDER MANTISSA
+ 07273 7450 SNA /ZERO?
+ 07274 1046 TAD ACL /YES-HOW ABOUT LOW?
+ 07275 7450 SNA
+ 07276 1053 TAD AC1 /LOW=0, IS OVRFLO BIT ON?
+ 07277 7650 SNA CLA
+ 07300 5313 JMP ZEXP /#=0-ZERO EXPONENT
+ 07301 7332 NORMLP, CLA CLL CML RTR /NOT 0-MAKE A 2000 IN AC
+ 07302 1045 TAD ACH /ADD HI ORDER MANTISSA
+ 07303 7440 SZA /HI ORDER = 6000
+ 07304 5307 JMP .+3 /NO-CHECK LEFT MOST DIGIT
+ 07305 1046 TAD ACL /YES-6000 OK IF LOW=O
+ 07306 7640 SZA CLA
+ 07307 7710 SPA CLA /2,3,4,5,ARE LEGAL LEFT MOST DIGS.
+ 07310 5314 JMP FFNORR /FOR NORMALIZED #-(+2000=4,5,6,7)
+ 07311 4534 JMS I (AL1BMP /SHIFT AC LEFT AND BUMP ACX DOWN
+ 07312 5301 JMP NORMLP /GO BACK AND SEE IF NORMALIZED
+ 07313 3044 ZEXP, DCA ACX
+ 07314 3053 FFNORR, DCA AC1 /DONE W/NORMALIZE - CLEAR AC1
+ 07315 5671 JMP I FFNOR /RETURN
+
+ 07316 0000 LPBUF4, ZBLOCK 60
+ 07376 7400 LPBUFE
+ 07377 6514
+ 7400 PAGE
+
+
+
+
+
+ 4-29
+\f
+
+
+ CHAPTER 5
+
+ LIBRA AND FORLIB
+
+
+ The binary output of an assembly under RALF is called a RALF module.
+ Every RALF module consists of an External Symbol Dictionary (or ESD)
+ and associated text. The ESD lists all global symbols defined in the
+ assembly, while the text contains the actual binary output along with
+ relocation data.
+
+ There are three major classes of global symbols. Entry points are
+ global symbols defined in a module and referenced by code in other
+ modules. Thus, entry points include the names of all modules and the
+ names of all globally callable subroutines within modules. Externs are
+ global symbols that are referenced in a module but not defined in that
+ module. For example, the entry point of module A would appear as an
+ extern if referenced in module B. The COMMON area comprises a third
+ class of global symbols including all global symbols which define
+ COMMON.
+
+ A FORTRAN IV library is a specially formatted file, created with
+ LIBRA, consisting of a library catalog (which lists section names and
+ entry points of library modules) and a set of RALF modules, perhaps
+ interspersed with empty subfiles. The loader uses one such library,
+ specified by the user, to resolve externs while building a loader
+ image file. The general structure of a FORTRAN IV library is:
+
+ ----------------------------------------------------------------
+ | CATALOG | MODULE | FREE | MODULE | MODULE | \
+ | | | AREA | | | etc. /
+ | | | | | | \
+ -----------------------------------------------------------------
+
+ LIBRA is a very simple program, basically a file-to-file copy inside
+ several nested loops. The outer loop begins at START, and calls the
+ command decoder for specification of the library and input files. If
+ no library is specified, the previous library name is used (initially
+ this is SYS:FORLIB.RL). If a new name is given, but no extension is
+ specified, .RL is forced. A check is made to verify that the
+ specified library is on a file-structured device, and the handler is
+ FETCHed.
+
+ At ZTEST, the /Z switch is tested. If it was set, control passes to
+ NEWLIB to create a new library. Otherwise, an attempt is made to find
+ an old library of the specified name on the device. If it fails,
+ control passes to NEWLIB. Otherwise, the catalog of the old library
+ is read and scanned to determine the starting block of available
+ space. This is stored at LAVAIL. Control then passes to GETINF to
+ begin reading input files.
+
+ If /Z was set, or the specified library isn't found, a new library is
+ entered at NEWLIB, and an empty catalog is written. Control passes to
+ GETINF. There, a check is made to determine whether input is
+
+ 5-1
+\f
+
+
+ presently coming from another library. If it is, control passes to
+ INLIB to obtain the next module from the library. Otherwise, the next
+ input file is obtained from the command decoder area in field 1, and
+ if one exists, control passes to FTCHIN to load the handler. If there
+ is none, the /C switch is tested. If it is not set, control is passed
+ to LCLOSE to close the library. If it is set, however, the command
+ decoder is recalled to obtain a continuation of the preceding input
+ line, and control returns to NXTINF to look in the command decoder
+ area.
+
+ At FTCHIN, the unit, starting block, and length of the next input file
+ are obtained from the command decoder area, the appropriate device
+ handler is fetched, and at LUKMOD, the input file is read to ensure
+ that it is either a module or a library. If a library, control passes
+ to GOTLIB, which sets INLSW and goes to INLIB to obtain the first
+ module from the library. Otherwise, the length is checked against the
+ available length in the library, to ensure that this module can be fit
+ in, and control goes to NXTEBK to read the ESD.
+
+ At INLIB, the catalog of the library being input is read, and scanned
+ until a module is found with a starting block greater than the
+ starting block of the last input module (in the case of the first
+ module in a library, MODBLK, which normally contains the starting
+ block of a module, contains the starting block of the library, so this
+ scan yields the starting block of the first module in the library).
+ When the next module has been found, control returns to LUKMOD to
+ check the length of the module against the available length in the
+ library.
+
+ At NXTEBK, the end of the input module is scanned for entry point and
+ section names. Whenever one is found, the catalog of the output
+ library is scanned for a matching name. If a match is found, control
+ passes to GOTMAT, which prints the duplicated name, and if the /I
+ switch is set, asks the operator which name to keep. If he types N,
+ for new, control passes to DLETO to delete the old name. Otherwise,
+ control is passed to ESDLND to find the next entry point or section
+ name in the input. If /I is not set, /R is tested. If it is not set,
+ control is passed to ESDLND. If it is, control flows into DELTO,
+ where the old name is cleared, and the rest of the catalog is scanned
+ to find the first available name slot. Control then passes to INSERT.
+
+ If no match was found, the /I switch is tested. If it was set, the
+ operator is asked whether to include the name. If he types, N, for
+ no, control is passed to ESDLND. Otherwise, or if /I was not set, a
+ pointer is set up for the new name, and control passes to INSERT,
+ where the new name is added to the catalog.
+
+ When the entire ESD has been scanned, INCLUD is tested to determine
+ whether any name has been included in the catalog, and assuming at
+ least one has, the module is copied into the library, and LAVAIL is
+ updated to indicate the next available block in the library. Control
+ returns to GETINF for another module.
+
+
+
+ 5-2
+\f
+
+
+ LCLOSE receives control whenever the end of the input file string is
+ reached and /C is not set. Here, any remaining changes in the library
+ catalog are written, and if a new library was entered, it is closed.
+ Control passes to CATLST, to create a catalog listing. The second
+ output file, if any was specified, is opened, a title is output to it,
+ and at PRCAT, the entire contents of the catalog are listed. When
+ this process is complete, the output file is closed, and control
+ returns to start for more command decoder input.
+
+ User-coded modules may be added to the system library or incorporated
+ in a new library provided that entry points, variable storage
+ allocations, calling sequences, error conditions and the like are
+ handled with care.
+
+ Every library module must have a unique section (and entry) name(s).
+ The library supplied by DEC uses the character # before names where
+ duplication in the FORTRAN program may be possible. Note that this
+ character is acceptable to RALF, but is illegal in a FORTRAN source.
+ If more than one entry is required to the routine, they should be
+ listed as such using the pseudo-op ENTRY before they are encountered
+ as tags in the code. Thus, if a double precision tangent routine is
+ being written, it may be helpful to have an entry for a double
+ precision co-tangent calculation also. Appropriate code would be:
+
+ SECT DTAN
+ JA #DTAN
+ ENTRY DCOT
+ JA #DCOT
+ .
+ .
+ .
+ #DCOT,
+ .
+ .
+ .
+ #DTAN,
+
+ When routines will handle double precision or complex values, allocate
+ six words for their storage. Such routines can switch between the
+ STARTF (3 word format) and STARTE (6 word format) pseudo-ops as
+ required, being careful to define variables of the proper length to
+ keep track of temporary locations.
+
+ All user-written library routines are called by a JSR in STARTF mode.
+ Depending on the type of function, the routine must be coded to exit
+ as follows in order to return the result to the program:
+
+ Single precision Answer in AC in STARTF mode
+ (integer, real and logical)
+
+ FLDA ANSWER /In STARTF mode
+ JA RETURN /3 word result
+
+
+
+ 5-3
+\f
+
+
+ Double precision: Answer in AC in STARTE mode
+
+ FLDA ANSWER /In STARTE mode
+ JA RETURN /6 word result
+
+ Complex: Answer in location #CAC in
+ STARTE mode
+
+ EXTERN #CAC /Real part in first 3 words
+ STARTE /Imaginary in last 3 words
+ FLDA ANSWER /Exit in STARTE mode
+ FSTA #CAC /6 word result
+ JA RETURN
+
+ Routines should conform to the FPP FORTRAN calling sequence. An
+ example of that sequence follows:
+
+ SECT DTAN /Sector name
+ JA #DTAN /Jump to Start of Function
+ TEXT +DTAN + /6 characters for trace
+ /back feature must be
+ /immediately before index
+ /register assignment.
+ DTANXR, SETX XRDTAN /This tag referenced when
+ /returning to reset base
+ /page and index registers
+ SETB BPDTAN /if this routine called.
+
+ BPDTAN, F 0.0 /3 words each
+ XRDTAN, F 0.0 /These locations may be
+ /used for temporary storage or
+ ORG 10*3+BPDTAN /If this routine is called,
+ /will set up return to it.
+ FNOP
+ JA DTANXR
+ 0
+ DTNRTN, JA . /Return to calling program
+ BASE 0 /Still on caller's base page
+ #DTAN, STARTD /Start of subroutine
+ FLDA 10*3 /Get jump to caller's return jump
+ FSTA DTNRTN /Save for return from this routine
+ FLDA 0 /Get next location in caller's
+ /routine (pointer to argument list)
+ SETX XRDTAN /Change index registers to this
+ /routine's
+ SETB BPDTAN /Change base page to this routine's
+ BASE BPDTAN /Change base page to this routine's
+ FSTA TEMP /Save pointer
+ LDX 1,1 /Set up XRL
+ FLDA% TEMP,1 /Get address of argument list
+ FSTA TEMP /Save it
+ STARTE /A double precision routine
+ FLDA% TEMP /Get variable
+ FSTA TEMP /Save variable
+
+ 5-4
+\f
+
+
+ .
+ .
+ . /Calculate result
+ .
+ .
+ .
+ FLDA ANSWER /Load answer
+ JA DTNRTN /Exit
+
+ The following conventions must be observed to return to the calling
+ program at the correct location, to permit the error trace back
+ feature to function properly, and to preserve index registers and base
+ page integrity.
+
+ Locations 0 and 30 of the called (user-coded) program are determined
+ by a statement in the form ORG 10*3+BPAGE which must be followed by a
+ two-word jump to the index register and base page assignment
+ instructions JA BPXR. In the above example, the code is:
+
+ ORG 10*3+BPDATN
+ FNOP
+ JA DTANXR
+
+ By saving the contents of location 30 of the calling program (FLDA
+ 10*3,FSTA RETURN) for the return exit, the called program executes
+ (when control is returned to it) a JA BPXR to its base page and index
+ register assignment statement. In the calling program this resets the
+ index registers and base page and then returns to execute the
+ instruction in the calling program. In the tangent example above, the
+ code is:
+
+ FLDA 10*3
+ FSTA DTNRTN
+
+ which creates the instruction
+
+ JA xxx
+
+ at the tag DTNRTN, where xxx is the location in the calling routine
+ whose function corresponds to DTANXR in DTAN.
+
+ When called, the routine must assign its own base page and index
+ registers (SETX XROWN, SETB BPOWN). If arguments are to be passed to
+ the called routine, a scheme such as illustrated above permits any
+ number of arguments to be passed from the calling program and saved on
+ the base page of the called program, in this case just two arguments.
+
+ The corresponding code for the calling program (as created by the
+ compiler) is:
+
+
+
+
+
+
+ 5-5
+\f
+
+
+ EXTERN DTAN
+ JSR DTAN
+ JA .+4 /Jump past all arguments
+ JA A /Argument
+ .
+ .
+ .
+ FSTA Q /Save result in some variable
+
+ The FORTRAN for such code is:
+
+ Q = DTAN (A)
+
+ The calling sequence is also discussed in Chapter 2.
+
+ To permit the error trace back feature to function properly, a TEXT
+ statement followed by a six alphanumeric character name is required
+ immediately before the index register and base page assignment
+ statements. Thus, if the cotangent routine includes a JSR TAN and an
+ unacceptable argument is passed to the tangent function, the trace
+ back indicates the location of the problem by a sequence such as:
+
+ DIV0 MAIN
+ ARGUMENT
+ 7777 SIN
+ 0000 TAN
+ 0000 COT
+ 0007 MAIN
+
+ (Line numbers are not relevant in RALF modules such as TAN and SIN:
+ they are meaningful only in FORTRAN source programs.)
+
+ A new library routine may call other new or existing library routines
+ as part of its function, as well as the error handling function of the
+ run-time system. To invoke the error message program, code such as
+ the following is required:
+
+ EXTERN #ARGER
+ MERROR, TRAP4 #ARGER
+
+ Then any condition encountered in the program that is an error should
+ jump to MERROR. For example, if an argument of <=0 is illegal, it
+ could be examined and handled as follows:
+
+ FLDA% ARG2
+ JLE MERROR /<0 error
+ FSTA NEXT / Save non-zero value
+
+ In this case, the TRAP4 #ARGER at MERROR will produce the message BAD
+ ARG DTAN nnnn followed by traceback and program termination. If a new
+ library routine would like to use an existing library routine, a JSR
+ to that routine is required. The sequence for passing arguments is:
+
+
+
+ 5-6
+\f
+
+
+ EXTERN ATAN2
+ JSR ATAN2
+ JA .+6 /Execute upon exit from
+ JA A /1st arg
+ JA B /2nd arg
+ FSTA ANSWER /Save answer
+
+ The arguments must be referenced in the order expected by the called
+ routine and must agree in number and type. The following routines can
+ can be used in this manner:
+
+ ROUTINE ARGUMENTS PASSED\r _______ ________________
+
+ AMOD Address of X then Y
+ SQRT Address of X
+ ALOG10 Address of X
+ EXP Address of X
+ SIN Address of X
+ COS Address of X
+ TAN Address of X
+ SIND Address of X
+ COSD Address of X
+ TAND Address of X
+ ASIN Address of X
+ ACOS Address of X
+ ATAN Address of X
+ ATAN2 Address of X then Y
+ SINH Address of X
+ COSH Address of X
+ TANH Address of X
+ DMOD Address of X then Y
+ DSIGN Address of X then Y
+ DSIN Address of X
+ DLOG Address of X
+ DSQRT Address of X
+ DCOS Address of X
+ DLOG10 Address of X
+ DATAN2 Address of X then Y
+ DATAN Address of X
+ DEXP Address of X
+ CMPLX Address of X
+ CSIN Address of X
+ CCOS Address of X
+ REAL Address of X
+ AIMAG Address of X
+ CONJG Address of X
+ CEXP Address of X
+ CLOG Address of X
+ CABS Address of X
+ CSQRT Address of X
+
+ For real and double precision routines, the result is returned via the
+ FAC (3 or 6 words, respectively). For complex routines, the result is
+ returned in #CAC (6 words).
+
+ 5-7
+\f
+
+
+ The TAN function from FORLIB is included here as an example of the
+ requirements just discussed. The TAN function calls two external
+ functions, has the standard calling sequence, and contains an error
+ condition exit.
+
+ / T A N
+ / - - -
+ /
+ /SUBROUTINE TAN(X)
+ SECT TAN /SECTION NAME
+ JA #TAN /JUMP AROUND BASE PAGE
+
+ EXTERN #ARGER
+ TANER, TRAP4 #ARGER /EXIT TO ERROR MESSAGE HANDLER
+ TEXT +TAN + /FOR ERROR TRACE BACK
+ TANXR, SETX XRTAN /START OF FORMAL CALLING SEQUENCE
+ SETB BPTAN
+ BTAN, FNOP /START OF BASE PAGE
+ 0
+ 0
+ XRTAN, F 0.0 /INDEX REGISTERS
+ TAN1, F 0.0 /LOCATIONS 21-42 OCTAL AVAILABLE
+ /FOR USER STORAGE
+ TAN2, F 0.0
+ ORG 10*3+BPTAN /SET UP FOR A RETURN
+ /TO THIS ROUTINE
+ FNOP
+ JA TANXR /JUMP TO XR + RP ASSIGNMENT
+ 0
+ TANRTN, JA .
+ BASE 0
+ #TAN, STARTD
+ FLDA 10*3 /SAVE RETURN JUMP
+ FSTA TANRTN
+ FLDA 0 /GET NEXT LOCATION
+ /IN CALLING PROGRAM
+ SETX XRTAN /SET UP FOR TAN'S INDEX REGS
+ SETB BPTAN /SET UP FOR TAN'S BP
+ BASE BPTAN
+ LDX 1,1
+ FSTA BPTAN
+ FLDA% BPTAN,1 /GET ADDRESS OF X
+ FSTA BPTAN
+ STARTF
+ FLDA% BPTAN /GET X
+ JEQ TANRTN /IF 0 RETURN NOW
+ FSTA TAN1 /SAVE FOR A SECOND
+ EXTERN COS
+ JSR COS /TAKE COS(X)
+ JA .+4 /JUMP AROUND ARGUMENT LIST
+ JA TAN1 /REFERENCE TO PASSED ARGUMENT
+ JEQ TANER /COS=0. A NO-NO
+ FSTA TAN2 /SAVE IT
+ EXTERN SIN
+
+ 5-8
+\f
+
+
+ JSR SIN /NOW TAKE SIN(X)
+ JA .+4 /JUMP AROUND ARGUMENT LIST
+ JA TAN1 /REFERENCE TO ARGUMENT
+ FDIV TAN2 /DIV BY COS(X)
+ JA TANRTN /EXIT
+
+ The library routine ONQI illustrates many of the same conventions.
+ This listing may also prove valuable as a guide to interfacing with
+ the run-time system.
+
+ FIELD1 ONQI /ROUTINE TO ADD A
+ /HANDLER TO INTERRUPT SKIP CHAIN
+ /PUT THIS CODE IN FIELD 1
+ 0
+ JMP SETINT /SET UP INT INITIALLY
+ ISZ ONQI /BUMP ARGUMENT POINTER
+ ISZ INTQ+1 /BUMP INTERRUPT Q POINTER
+ DCA% INTQ+1 /STICK IOT ONTO INT Q
+ TAD XSKP /FOLLOWED BY A SKIP
+ ISZ INTQ+1
+ DCA% INTQ+1 /ONTO INT Q
+ ISZ ONQI /SKIP FIRST WORD OF ADDR
+ ISZ INTQ+1
+ ONQISW, TAD% ONQI /GET INT HANDLER ADDRESS
+ ISZ ONQI
+ DCA% INTADR+1 /ONTO ADDRESS STACK
+ TAD INTADR+1 /NOW MAKE JMS%
+ AND L177
+ TAD L4600
+ DCA% INTQ+1 /ONTO INT Q
+ ISZ INTADR+1
+ ISZ IQSIZE /ROOM FOR MORE?
+ JMP% ONQI /YES
+ TAD .-1 /NO, CLOSE OUT THE SUBR
+ DCA ONQI+1
+ JMP% ONQI
+ SETINT, TAD ONQISW /DO THIS PART ONLY ONCE
+ DCA ONQI+1
+ CDF
+ TAD XSKP /FIX UP #INT
+ DCA% XINT+1 /PUT SKIP INST. FIRST
+ ISZ XINT+1
+ TAD INTQ+1
+ DCA% XINT+1 /GET ADDR. OF USER'S ROUTINE
+ ISZ XINT+1 /ADD TO INTERRUPT CALL
+ TAD CIFCDF /GET FIELD INSTRUCTION
+ /FIELD1 SECTION INSURES ITS IN FIELD 1
+ DCA% XINT+1
+ CIFCDF, CDF CIF 10
+ JMP ONQI+1 /BACK TO ONQI
+ EXTERN #INT
+ XINT, ADDR #INT /POINTS TO INT RTN IN COMMON
+ INTQ, ADDR IHANDL /MUST USE 15 BIT ADDRESS
+
+
+ 5-9
+\f
+
+
+ INTADR, ADDR IHADRS / "
+
+ IQSIZE, -5
+ XSKP, SKP
+ L177, 177
+ L4600, 4600
+ CDF CIF
+ JMP% IHANDL
+ IHANDL, 0
+ REPEAT 16
+ JMP IHANDL-2
+ IHADRS, 0;0;0;0;0 /CAN SET UP 1-5 DEVICES
+
+
+ ENTRY ONQB /USE "ENTRY" TO PERMIT
+ /ACCESS FROM OUTSIDE OF SECTION
+ /ROUTINE TO SET UP AN IDLE JOB
+ ONQB, 0
+ JMP SETBAK /SETUP #IDLE
+ TAD% ONQB /GET ADDRESS OF IDLE JOB
+ ONQBSW, ISZ ONQB
+ DCA% BAKADR+1 /STORE ONTO BACKGROUND JOB Q
+ TAD BAKADR+1 /MAKE A JMS%
+ ISZ BAKADR+1
+ AND L177
+ TAD L4600
+ ISZ BAKQ+1
+ DCA% BAKQ+1
+ ISZ BQSIZE /MORE ROOM?
+ JMP% ONQB /YES
+ TAD .-1 /NO, CLOSE THE DOOR
+ DCA ONQB+1
+ JMP% ONQB
+ SETBAK, TAD ONQBSW /CLOSE OFF #IDLE INITIALIZATION
+ DCA ONQB+1
+ CDF
+ TAD XSKP /FIX UP #IDLE
+ DCA% XIDLE+1 /ADD SKIP TO IDLE CALL
+ TAD BAKQ+1 /GET ADDRESS OF ROUTINE
+ ISZ XIDLE+1
+ DCA% XIDLE+1
+ ISZ XIDLE+1
+ TAD CIFCDF /GET FIELD INSTR.
+ DCA% XIDLE+1
+ CIF CDF 10
+ JMP ONQB+1
+ EXTERN #IDLE /EXTERNAL REFERENCE
+ XIDLE, ADDR #IDLE
+
+ BAKQ, ADDR BAKRND
+
+ BAKADR, ADDR BHADRS
+
+
+
+ 5-10
+\f
+
+
+ BQSIZE, -5
+ CDF CIF
+ JMP# BAKRND
+ BAKRND, 0
+ REPEAT 6
+ JMP BAKRND-2
+ BHADRS, 0;0;0;0;0 /1-5 JOBS
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ 5-11
+\f
+
+
+ APPENDIX A
+
+ RALF Assembler Permanent Symbol Table
+
+
+
+ Mnemonic Code Mnemonic Code\r ________ ____ ________ ____
+
+ FPP Memory Reference Instructions FPP Special Format Instructions
+
+ FADD 1000 ADDX 0110
+ FADDM 5000 ALN 0010
+ FDIV 3000 ATX 0020
+ FLDA 0000 FCLA 0002
+ FMUL 4000 FEXIT 0
+ FMULM 7000 FNEG 0003
+ FSTA 6000 FNOP 0040
+ FSUB 2000 FNORM 0004
+ FPAUSE 0001
+ IOT'S JA 1030
+ JAC 0007
+ FPINT 6551 JAL 1070
+ FPICL 6552 JEQ 1000
+ FPCOM 6553 JGE 1010
+ FPHLT 6554 JGT 1060
+ FPST 6555 JLE 1020
+ FPRST 6556 JLT 1050
+ FPIST 6557 JNE 1040
+ JSA 1120
+ 8-Mode Memory Reference Instructions JSR 1130
+ JXN 2000
+ AND 0000 SETB 1110
+ TAD 1000 SETX 1100
+ ISZ 2000 STARTD 0006
+ DCA 3000 STARTE 0050
+ JMS 4000 STARTF 0005
+ JMP 5000 TRAP3 3000
+ IOT 6000 TRAP4 4000
+ OPR 7000 TRAP5 5000
+ TRAP6 6000
+ TRAP7 7000
+ XTA 0030
+
+
+
+
+
+
+
+
+
+
+
+
+
+ A-1
+\f
+
+
+ Mnemonic\r ________
+
+ Pseudo-Operators
+
+ ADDR
+ BASE
+ COMMON
+ COMMZ
+ DECIMAL
+ DPCHK
+ E
+ END
+ ENTRY
+ EXTERN
+ F
+ FIELD1
+ IFNDEF
+ IFNEG
+ IFNZRO
+ IFPOS
+ IFREF
+ IFZERO
+ INDEX
+ LISTOFF
+ LISTON
+ OCTAL
+ ORG
+ REPEAT
+ SECT
+ SECT8
+ TEXT
+ ZBLOCK
+ IFFLAP
+ IFRALF
+ IFSW
+ IFNSW
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ A-2
+\f
+
+
+
+ APPENDIX B
+
+ ASSEMBLY INSTRUCTIONS for OS/8
+
+
+ The following sequence of commands may be used to assemble the OS/8
+ FORTRAN IV system programs. It is assumed that all PAL language
+ sources reside on DSK. In this example, DTA1 is shown as the target
+ device, however any other device could be used via the appropriate
+ ASSIGN command. Note that PASS2O.SV is produced by conditional
+ assembly of PASS2.PA and that the "O" in PASS2O is an oh, not a zero.
+ The initial dot and asterisk characters on every command line shown
+ are printed by the monitor. All other characters (except carriage
+ return, in some cases) are typed by the user. Type CTRL/Z after each
+ of the three system pauses at point (1), to continue assembly of
+ PASS2O. Type ALT MODE to produce the "$" character.
+
+ .ASSIGN DTA1 DEV
+ .R PAL8
+ *F4.BN,LIST.LS<F4$
+ .R ABSLDR
+ *F4$
+ .SAVE DEV F4=0;12200$
+ .R PAL8
+ *PASS2.BN,LIST.LS<PASS2$
+ .R ABSLDR
+ *PASS2$
+ .SAVE DEV PASS2=0;5000$
+ .R PAL8
+ *PASS2O.BN,LIST.LS<TTY:,DSK:PASS2$OVERLY=1 (1)
+ .R ABSLDR
+ .PASS2O$
+ .SAVE DEV PASS2O=0;7605$
+ .R PAL8
+ *PASS3.BN,LIST.LS<PASS3$
+ .R ABSLDR
+ *PASS3$
+ .SAVE DEV PASS3=0;400$
+ .R PAL8
+ *RALF.BN,LIST.LS<RALF$
+ .R ABSLDR
+ *RALF$
+ .SAVE DEV RALF=0;200$
+ .R PAL8
+ *LOAD.BN,LIST.LS<LOAD$
+ .R ABSLDR
+ *LOAD$
+ .SAVE DEV LOAD=0;200$
+ .R PAL8
+ *FRTS.BN,LIST.LS<RTS,RTL$
+ .R ABSLDR
+ *FRTS$
+ .SAVE DEV FRTS=0;200$
+
+ B-1
+\f
+
+
+ .R PAL8
+ *LIBRA.BN,LIST.LS<LIBRA$
+ .R ABSLDR
+ *LIBRA$
+ .SAVE DEV LIBRA=0;200$
+ .
+
+
+
+ ASSEMBLY INSTRUCTIONS for OS/278 and OS/78
+
+
+ The following BATCH file lists the sequence of commands that may be
+ used to assemble the OS/278 FORTRAN IV system programs. All the PAL
+ language sources reside on the device assigned to SRCE, and all output
+ files go to the device assigned to TARG. The SYS device is used to
+ store the binary files until the programs are SAved. Note that
+ PASS2O.SV is produced by conditional assembly of PASS2.PA and that the
+ "O" in PASS2O is an oh, not a zero.
+
+ If these commands are typed in, the initial "}" and asterisk (*)
+ characters on every command line shown are printed by the monitor.
+ All other characters (except carriage return, in some cases) are typed
+ by the user.
+
+ To use these commands with OS/78, replace the "}" with a ".".
+
+
+ $JOB (FORGEN.BI) ASSEMBLE FORTRAN IV FOR OS278
+
+ /}ASSIGN XXX SRCE where XXX is the device containing the source files
+ /}ASSIGN YYY TARG where YYY is the output device for the .SV files
+
+ }PAL F4<SRCE:F4
+ }LOAD F4
+ }SAVE TARG:F4.SV;12200=100
+ }DELETE F4.BN
+
+ }PAL PASS2<SRCE:PASS2
+ }LOAD PASS2
+ }SAVE TARG:PASS2.SV;5000=100
+ }DELETE PASS2.BN
+
+ }PAL PASS2O<SRCE:PASS2O,PASS2
+ }LOAD PASS2O
+ }SAVE TARG:PASS2O.SV;7605=100
+ }DELETE PASS2O.BN
+
+ }PAL PASS3<SRCE:PASS3
+ }LOAD PASS3
+ }SAVE TARG:PASS3.SV;400=100
+ }DELETE PASS3.BN
+
+
+
+ B-2
+\f
+
+
+ }PAL LOAD<SRCE:LOAD
+ }LOAD LOAD
+ }SAVE TARG:LOAD.SV;200=100
+ }DELETE LOAD.BN
+
+ }PAL FRTS<SRCE:RTS,RTL /W/K
+ }LOAD FRTS
+ }SAVE TARG:FRTS.SV;200=100
+ }DELETE FTRS.BN
+
+ }PAL RALF<SRCE:RALF /W
+ }LOAD RALF
+ }SAVE TARG:RALF.SV;200=100
+ }DELETE RALF.BN
+
+ }PAL LIBRA<SRCE:LIBRA
+ }LOAD LIBRA
+ }SAVE TARG:LIBRA.SV;200=100
+ }DELETE LIBRA.BN
+
+ $END
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ B-3
+\f
+
+
+
+ INDEX
+
+
+
+ Argument passing, 2-7 Idle jobs, 4-1
+ Arithmetic expression Indirect addressing, 2-5
+ analyzer, 1-1 Interrupts,
+ Servicing, 4-1, 4-14
+ Spurious, 4-14
+ Background Jobs, 4-1
+ Binary buffer table, 3-9
+ Binary section table, 3-10 Keyword, 1-1
+ Block count sequence number, 4-13
+
+ LIBRA, 5-2
+ COMMON information block, 1-7 Library, 2-1
+ Communication, 2-7 Format, 5-1
+ COMMZ sections, 2-10 Line printer handler, 4-13
+ Compilation, 1-1 Literals, 1-4, 1-5
+ Compiler symbol table, 1-2 Loader, 3-1
+ Core maps, 3-2 to 3-4
+ Image file, 3-13
+ Device handlers, 4-14 Subroutines,
+ Device flag handlers, 4-2 Loader symbol table, 3-1, 3-7
+ Dimension information block, 1-5
+ DSRN table, 4-8
+ Magic number, 1-5
+ Mixing code, 2-6
+ Module, 2-1
+ Entry point, 2-1 Module count table, 3-12
+ EQUIVALENCE information table, Module descriptor table, 3-11
+ 1-6
+ ESD, 2-1, 2-2, 2-4
+ ESD correspondence table, 3-9 Off-page references, 2-17
+ External symbol, 2-2 Optimized code, 2-9
+ External symbol dictionary, 2-1, Output codes, 1-7
+ 2-2, 2-4 Overlay table, 3-10
+
+
+ FIELD1 sections, 2-11 /P option, 4-20
+ Files, 4-9 Page boundaries, 2-11
+ Formatted I/O, 4-9 PASS1, 1-1
+ FRTS Output, 1-7
+ Calling sequence, 4-3 Subroutines, 1-10
+ Core maps, 4-5 to 4-7 PASS2, 1-12
+ Entry points, 4-4 Error list, 1-14
+ Initialization, 4-13 Skeleton tables, 1-14
+ Page zero, 4-10 Symbol table, 1-14
+ Subroutines, 1-16
+ Header block, 3-13 Pass3, 1-17
+
+
+
+
+ X-1
+\f
+
+
+ PDP-8 code, 2-5
+ Program loading, 3-9
+ Program termination, 4-21
+ Pseudo-ops, 2-3 to 2-6,
+ 2-16 to 2-18, 5-3
+
+
+ RALF, 2-1
+ Expressions, 2-3
+ Symbol table, 2-3
+ RALF output file, 2-4
+
+
+ Section, 2-1
+ Section types, 2-9
+ Statement number, 1-3
+ Subroutine calls, 2-7
+ Subroutine return sequence, 2-8
+ Symbol table,
+ Compiler, 1-14
+ Loader, 3-7
+ RALF, 2-4
+
+
+ Termination, program, 4-21
+ Text, 2-1
+ TRAP3 and TRAP4, 2-6
+
+
+ Variable type word, 1-2
+
+
+ 8-mode sections, 2-11
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ X-2
+\f
+
+
+ DEC-S8-LFSSA-A-D
+ OS/8 FORTRAN IV
+ SOFTWARE SUPPORT MANUAL
+
+
+ READER'S COMMENTS
+
+
+ Digital Equipment Corporation maintains a continuous effort to improve
+ the quality and usefulness of its publications. To do this effectively
+ we need user feedback--your critical evaluation of this document.
+
+
+ Did you find errors in this document? If so, please specify by page.
+
+ ______________________________________________________________________
+ ______________________________________________________________________
+ ______________________________________________________________________
+ ______________________________________________________________________
+ ______________________________________________________________________
+
+
+ How can this document be improved?
+
+ ______________________________________________________________________
+ ______________________________________________________________________
+ ______________________________________________________________________
+ ______________________________________________________________________
+ ______________________________________________________________________
+
+
+ How does this document compare with other technical documents you
+ have read?
+
+ ______________________________________________________________________
+ ______________________________________________________________________
+ ______________________________________________________________________
+ ______________________________________________________________________
+ ______________________________________________________________________
+
+
+
+ Job Title_________________________________ Date:______________________
+
+ Name:__________________________ Organization:_________________________
+
+ Street:________________________ Department:___________________________
+
+ City:_________________ State:___________ Zip or Country_______________
+
+
+
+
+
+
+
+\f
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ -------------------------------Fold Here------------------------------
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ -----------------Do Not Tear - Fold Here and Staple-------------------
+
+ +---------------+
+ | FIRST CLASS |
+ | PERMIT NO. 33 |
+ | MAYNARD. MASS.|
+ +---------------+
+ BUSINESS REPLY MAIL ========
+ NO POSTAGE STAMP NECESSARY IF MAILED IN THE UNITED STATES ========
+ ======================================================================
+ Postage will be paid by: ========
+ ========
+ +-+-+-+-+-+-+-+ ========
+ |d|i|g|i|t|a|l| ========
+ +-+-+-+-+-+-+-+ ========
+ Digital Equipment Corporation ========
+ Software Information Service ========
+ Software Engineering and Services ========
+ Maynard, Massachusetts 01754 ========
+
--- /dev/null
+/ SPACE WAR
+/
+/ INTERPLANETARY DEATH AND DESTRUCTION ON YOUR
+/ LAB-8/E - NEEDS EAE!
+/
+/ HACHTI VARIANT FOR LAB-8/E - WITH JOYSTICK SUPPORT.
+/
+/ EVAN SUITS
+/
+/ THIS VERSION WORKS OFF EITHER THE BLUE RIBBON CONNECTOR OR THE
+/ SR. WHEN THE PROGRAM IS STARTED (AT 0200) OR RESTARTED THE
+/ SR WILL BE TESTED AND IF =0000 WILL BE USED FOR THE COMMAND
+/ INPUT. OTHERWISE, THE BLUE RIBBON CONNECTOR (AX08 * C0-C7 *
+/ XR OPTION ONLY) CONTINGENCY INPUTS WILL BE USED.
+/
+/ WHEN THE PROGRAM IS STARTED THE TWO SHIPS SHOULD
+/ APPEAR ON THE SCREEN WITH SHIP 'ONE' ON THE LEFT, SHIP
+/ 'TWO' ON THE RIGHT.
+/
+/ THE COMMAND WORD BIT ASSIGNMENTS ARE:
+/
+/ SR BIT: C: FUNCTION:
+/
+/ 0 0 SHIP ONE ROTATES LEFT
+/
+/ 1 1 SHIP ONE ROTATES RIGHT
+/
+/ 2 2 SHIP ONE ACCELERATES
+/
+/ 3 3 SHIP ONE FIRES
+/
+/
+/
+/ 8 4 SHIP TWO ROTATES LEFT
+/
+/ 9 5 SHIP TWO ROTATES RIGHT
+/
+/ 10 6 SHIP TWO ACCELERATES
+/
+/ 11 7 SHIP TWO FIRES
+/
+/
+/
+/ NOTE THAT TURNING RIGHT AND LEFT SIMULTANEOUSLY THROWS
+/ THE SHIP INTO HYPERSPACE. IN THE CURRENT VERSION THE ODDS
+/ ARE IN FAVOR OF YOUR MAKING IT BACK SAFELY. THE GAME IS OVER
+/ WHEN ONE OR BOTH OF THE SHIPS HAVE BEEN DESTROYED AND THE
+/ WINNER (IF ANY) IS IN NORMAL SPACE. WHEN THE WINNER
+/ HAS BEEN ANNOUNCED, HIT ANY TTY KEY TO RESTART.
+/
+
+
+/****************************************************************
+
+/***************************
+/ EAE CODES
+DVI=7407
+SWBA=7447
+MUY=7405
+
+/***************************
+/ CLOCK OPERATIONS
+
+CLZE=6130 / CLEAR CLOCK ENABLE REGISTER PER AC
+CLSK=6131 / SKIP ON CLOCK FLAG
+CLOE=6132 / SET CLOCK ENABLE REGISTER PER AC
+CLAB=6133 / AC REGISTER TO CLOCK COUNTER REGISTER
+CLEN=6134 / CLOCK ENABLE REGISTER TO AC
+CLSA=6135 / STATUS TO AC
+CLBA=6136 / CLOCK BUFFER REGISTER TO AC
+CLCA=6137 / CLOCK COUNTER REGISTER TO AC
+
+/ BITS IN CLOCK ENABLE REGISTER
+CREXT=0100 / EXTERNAL SOURCE
+CR2=0200 / 10**2 per second
+CR3=0300 / 10**3 per second
+CR4=0400 / 10**4 per second
+CR5=0500 / 10**5 per second
+CR6=0600 / 10**6 per second
+
+COVSTAT=4000
+CMFREE=0000 / 4096 FIXED FREE RUN
+CMPROG=1000 / PROGRAMMED DELAY
+
+CADC=0040 / START ADC ON OVERFLOW
+CINH=0020 / INHIBIT CLOCK
+CION=0010 / INTERRUPT ENABLE
+
+CEV3=0004 / EVENT 3 ENABLED
+CEV2=0002 / EVENT 2 ENABLED
+CEV1=00001 / EVENT 1 ENABLED
+
+/ VC8-E OPCODES
+DIXY=6055 / INTENSIFY
+DILX=6053 / LOAD X
+DILY=6054 / LOAD Y
+DILE=6056 / LOAD ENABLES FROM A
+DISD=6052 / TEST FOR READY
+
+/********************************************************************
+/ JOYSTICK OPERATIONS
+JOR=6421 / OR JOYSTICK TO AC
+JLOAD=6422 / CLEAR AC AND READ JOYSTICK
+
+
+JB1L=0010
+JB1R=0004
+JB1U=0002
+JB1D=0020
+JB1B=0001
+
+JB2L=4000
+JB2R=2000
+JB2U=1000
+JB2D=0200
+JB2B=0400
+
+/****************************************************************
+/ SYMBOL DEFINITIONS FOR PAL8-PAL10
+
+XRIN=NOP / DIGITAL INPUT?
+XRCL=NOP
+
+/DSB=XXXX / SET BRIGHTNESS - MUST BE COMMENTED OUT!!!
+
+DXC=JMS I IVCLDX / X VALUE CONTROL?
+DYC=JMS I IVCLDY / Y VALUE CONTROL?
+
+DXL=0000 / X VALUE LOAD FLAG?
+DYL=0000 / Y VALUE LOAD FLAG?
+DIS=0000 / ANOTHER STRANGE FLAG
+
+
+
+/****************************************************************
+/
+/ THIS PROGRAM RELIES ON THE PROGRAM INTERUPT FACILITY FOR
+/ REAL WORLD TIMING PURPOSES.
+/
+
+ *0
+
+ 0 /EFFECTIVE JMS 0 ON PROGRAM INTERUPT
+ JMP I 2 /EXIT IMMEDIATLY TO SERVICE ROUTINE
+ INTSER
+
+EMPTY, 0 /THESE LOCATIONS ARE RESERVED FOR
+ODT1, 0 /DEBUGGERS, ETC.
+ODT2, 0
+ODT3, 0
+
+/
+/ ALL THE AUTO INDEX REGISTERS ARE NAMED BUT NOT ALL OF
+/ THEM ARE USED. THE STATUS OF ANY GIVEN REGISTER CANNOT
+/ BE DETERMINED AT ANY TIME EXCEPT BY CAREFUL INSPECTION OF
+/ THE CODE.
+/
+
+ *10
+
+AUTO10, 0
+AUTO11, 0
+AUTO12, 0
+AUTO13, 0
+AUTO14, 0
+AUTO15, 0
+AUTO16, 0
+AUTO17, 0
+
+/
+/ THE FOLLOWING ARE THE DATA FILES FOR THE TWO SPACE SHIPS
+/ AS WELL AS CERTAIN OTHER PARAMETERS FOR CALCULATING POSITIONS
+/ AND SO ON. THE ORDER OF THE LOCATIONS MUST BE PRESERVED
+/ ALTHOUGH THE SIZE OF THE TABLES MAY BE VARIED
+/
+
+ *20
+
+ONEOUT, 0 /IF NON-ZERO CONTAINS REAMINING TIME OF EXPLOSION
+ONECNT, 0 /NUMBER OF POINTS IN FIGURE TO BE DISPLAYED
+ONEFLG, 0 /IN OR OUT OF NORMAL SPACE
+ONETHE, 0 /ANGLE OF ORIENTATION ON SCREEN
+ONEVEX, 0 /X COMPONENT OF VELOCITY
+ONEVEY, 0 /Y COMPONENT OF VELOCITY
+ONEPEX, 0 /X POSITION (12 BITS)
+ONEPEY, 0 /Y POSITION (12 BITS)
+ONESIN, 0 /SINE OF ANGLE
+ONECOS, 0 /COSINE OF ANGLE
+ONEFIN, 0 /SET WHEN EXPLOSION DIES OUT
+
+TWOOUT, 0 /SAME CONTENT AND ORDER
+TWOCNT, 0 /AS ABOVE
+TWOFLG, 0
+TWOTHE, 0
+TWOVEX, 0
+TWOVEY, 0
+TWOPEX, 0
+TWOPEY, 0
+TWOSIN, 0
+TWOCOS, 0
+TWOFIN, 0
+
+
+/
+/ THESE LOCATIONS ARE USED BY THE "VECTOR GENERATOR" IN
+/ DISPLAYING THE FIGURES. A FOUR DOT VECTOR WILL BE DRAWN
+/ FROM XONE,YONE TO XTWO,YTWO WITH STEPS OF SIZE DIXTEM,DIYTEM
+/
+
+XONEDS, 0
+YONEDS, 0
+XTWODS, 0
+YTWODS, 0
+DIXTEM, 0
+DIYTEM, 0
+DISCNT, 0
+
+
+/
+/ THE NEXT LOCATIONS ARE USED BY CALPOS TO DO A FAST
+/ MULTIPLY TO HELP CALCULATE THE DISPLAY FILES.
+/
+T10SIN, 0
+T20SIN, 0
+T30SIN, 0
+T10COS, 0
+T20COS, 0
+T30COS, 0
+
+CALSIN, 0
+CALCOS, 0
+
+/
+/ NOW COME THE VARIOUS ODDS AND ENDS ONE USUALLY FINDS ON
+/ PAGE ZERO
+/
+
+SINE, SINEIN
+COSINE, COSINI
+MULT, MULTI
+RSHIFT, SHIFTR
+VECTOR, DISPLY
+CALPOS, POSCAL
+INTWRD, 0
+INTCNT, 0
+/CLOCK, 0
+HYPER, HYPSET
+MESOUT, CHARS
+THEADJ, THEAJI
+VEESCL, VEELIM
+ISHFT, DISHFT
+RESET1, RESE1
+GAMOVR, 0
+ACCFLG, 0
+ACCPER, -30
+MEXP, -400
+
+PROX, 0
+PROY, 0
+PROLIF, -360
+BUFTMP, 0
+ONEFIL, DISBUF
+TWOFIL, DISBUF+40
+
+P5, 5
+P10, 10
+P17, 17
+P20, 20
+P37, 37
+P40, 40
+P100, 100
+P132, 132
+P200, 200
+P400, 400
+P550, 550
+P3777, 3777
+
+M4, -4
+M6, -6
+M10, -10
+M11, -11
+M264, -264
+M200, -200
+M400, -400
+M550, -550
+
+IVCLDX, VCLDX
+IVCLDY, VCLDY
+
+/
+/ THE PROGRAM MAY BE STARTED OR RESTARTED AT ANYTIME AT 0200.
+/ THE DATA FILE ON PAGE ZERO IS CLEARED, ALL FLAGS INITIALIZED,
+/ AND THE SR EXAMINED. IF THE SR=0 THE DISPLAY UPDATE ROUTINES
+/ ARE SET TO PICK UP THE STATUS WORD FROM THE SR. IF THE SR
+/ DOES NOT EQUAL ZERO, THE STATUS WORD IS READ FROM THE EIGHT
+/ CONTINGENCY INPUTS ON THE BLUE RIBBON CONNECTOR OF THE AX08
+/ (XR OPTION ONLY). JUMP IS THEN TO THE DISPLAY
+/ FILE UPDATE TO START OFF THE GAME.
+/
+
+CDI=6201
+
+ *200
+
+ CDI 0 / SET FIELD0
+
+START, CAF /START OR RESTART HERE ANY OLD TIME
+
+ DIXY /TO GET THE VC8-E STARTED ONCE
+ LAS /SR
+/TMP SNA CLA
+ TAD SWRD /USE THE SR
+ TAD XROPT /USE THE BLUE RIBBON CONNECTOR
+ DCA COLDST /AND LEAVE IN THE TRAP LOCATION
+
+RESTRT, CLA CMA
+ XRCL
+ CLA CLL
+
+ TAD P17 /FIRST CLEAR THE POSITION AND DATA
+ DCA AUTO10 /TABLES OF THE TWO SHIPS
+ TAD TABLEN
+ DCA AUTO11
+ DCA I AUTO10
+ ISZ AUTO11
+ JMP .-2
+
+ TAD STRT1 /SET THE STARTING POSITIONS OF THE
+ DCA ONEPEX /TWO SHIPS
+ TAD STRT2
+ DCA TWOPEX
+ TAD P37 /SET TRIG FUNCTIONS JUST IN CASE
+ DCA ONECOS
+ TAD P37
+ DCA TWOCOS /ZERO DEGREES IS POINTING STRAIGHT UP
+ TAD ACCPER /SET COUNT FOR VELOCITY INCREASE
+ DCA ACCFLG
+ DCA ONEFIN /CLEAR ALL GAME END FLAGS
+ DCA TWOFIN
+ DCA GAMOVR
+ JMS I BUFSET /RESET ALL PROJECTILE DISPLAY BUFFERS
+
+ TCF /CLEAR OTHER REMAINING LIKELY FLAGS
+ PCF
+/ RRB
+
+ 6405 / CLEAR INTERRUPT ENABLE OF KERMIT'S SER PORT :-(
+
+ CLA CMA / ALL ONES
+ CLZE / CLEAR CLOCK CONFIG REGISTER
+ CLA
+ TAD CDELY / LOAD NEG DELAY
+ CLAB / LOAD TO CLOCK BUFFER
+ CLA
+ TAD CCNF / LOAD CLOCK CONFIG
+ CLOE / SET CONFIG BITS
+
+ CLA CLL
+ JMP COLDST /AND GO TO IT
+
+CCNF, CR4+CMPROG+CION+COVSTAT / CLOCK CONFIGURATION
+/CDELY, -310 / COUNTER PRESET (200) 50HZ
+CDELY, -246 / COUNTER PRESET (166) 60HZ
+
+/
+/ UPDATE IS REACHED WHENEVER THE PROGRAM IS STARTED OR THE
+/ CLOCK COUNT OVERFLOWS INDICATING TIME TO RECALCULATE THE
+/ THE DISPLAY FILES AND REFRESH THE DISPLAY. THE INTERUPT
+/ COUNT IS RESTORED, THE STATUS WORD IS PICKED UP FROM EITHER
+/ THE SR OR BRC, AND THE RECALCULATION PROCESS BEGUN.
+/
+
+UPDATE, CLA CLL /HERE ON CLOCK COUNT OVERFLOW.
+ /START NEXT SWEEP
+COLDST, 0 /TRAP TO READ SR OR BRC
+ JLOAD /LOAD JOYSTICK
+ DCA INTWRD /STORE TEMPORARILY
+ TAD INTWRD /MASK OUT LEFTMOST 4 BITS
+ RTR /FOR NUMBER ONE
+ RTR
+ AND LFTHAF
+ DCA INTTEM /AND STORE
+ TAD INTWRD /MASK OUT RIGHTMOST BITS FOR NUMBER TWO
+ AND RYTHAF
+ TAD INTTEM /ADD TOGETHER
+ JMP .+3 /AND CONTINUE
+
+CODST, XRIN /HERE FOR BRC - PICK UP AND CLEAR
+ XRCL
+ DCA INTWRD /CONTINUE
+ TAD M550 /RESTORE INTERUPT COUNT BEFORE NEXT
+ DCA INTCNT /UPDATE
+ ION /GET READY FOR THE NEXT CYCLE
+ TAD ACCFLG /ALLOW VELOCITY INCREASE THIS TIME?
+ IAC /ONLY WHEN ACCFLG=0
+ SMA SZA
+ TAD ACCPER /IF ZERO, RESET COUNT
+ DCA ACCFLG
+
+ JMP I .+1 /NOW GET DOWN TO WORK.
+ ONEUP
+
+BUFSET, SETBUF
+TABLEN, AUTO17-CALCOS
+INTTEM, 0
+LFTHAF, 0360
+RYTHAF, 0017
+STRT1, 1000
+STRT2, -1000
+SWRD, 2000-CODST /SWRD+XROPT=7000=NOP!
+XROPT, JMP CODST
+
+
+
+/
+/ THIS IS THE INTERUPT SERVICE ROUTINE. MOST OF THE
+/ INTERUPTS WILL BE FROM THE CRYSTAL CLOCK WHICH WILL BE
+/ COUNTED AND UNLESS THE COUNT OVERFLOWS THE INTERUPT IS
+/ DISMISSED IMMEDIATLY. IF THE COUNT OVER FLOWS, JMP IS TO
+/ UPDATE WITH IOF.
+/
+/ SPECIAL CASE IS KEYBOARD INTERUPT WHEN THE GAMOVR FLAG IS
+/ SET IN WHICH CASE THE GAME IS RESTARTED.
+/
+/ UNEXPECTED INTERUPTS ARE COUNTED AND AFTER ENOUGH OF THEM
+/ HAPPEN THE PROGRAM HALTS. IF THIS HAPPENS RELOAD OR FIND THE
+/ STRANGE FLAG
+/
+
+INTSER, DCA INTACC /HERE RIGHT AFTER INTERUPT - STORE
+ RAR /AC AND LINK
+ DCA INTLNK /FOR POSSIBLE CONTINUATION
+
+ CLSK /WAS IT THE CRYSTAL CLOCK?
+ JMP INTBUS /NO TRY SOMETHING ELSE
+
+ CLA IAC RTR /LOAD 4000
+ CLSA /GET CLOCKSTATUS AND RESET FLAG
+ CLA CLL
+ JMP UPDATE /YES, GO TO IT
+
+INTBUS, /HERE ON NON-CLOCK INTERUPT
+
+ KSF
+ JMP NOKEY /NOT THE KEYBOARD, THAT'S BAD!
+
+KBDIN, KCC /CLEAR KEYBOARD FLAG
+
+ KRB / RESET FLAG, CLEAR AC, READ DATA
+ AND KPAR / MASK OUT PARITY
+ TAD NCTRLC / ADD -3 (CTRL-C)
+ SNA CLA
+ JMP I KBOOT / REBOOT!
+
+ TAD GAMOVR /IS THE GAMEOVER
+ SZA CLA
+ JMP RESTRT /YES, RESTART
+
+ KRB
+ AND KPAR
+ TAD NCTRLD
+ SNA CLA
+ JMP RESTRT
+
+ JMP INTRET
+
+NOKEY, / STILL NOT FOUND INTERRUPT SOURCE :-(
+ TSF / SKIP IF PRINTER FLAG SET
+ JMP BADDIE / NOT THE PRINTER, NO NEW IDEAS - BAD
+ TCF / CLEAR THAT FLAG
+ JMP INTRET / AND GO HOME
+
+KBOOT, 7600
+KPAR, 177 / ANTI-PARITY MASK
+NCTRLC, 7775 / -3 (CTRL-C)
+NCTRLD, 7774 / -3 (CTRL-D)
+
+
+BADDIE, ISZ INTGLH /COUNT ONE BADDIE
+ SKP
+ HLT /HALT IF TOO MANY BADDIES
+
+INTRET, CLA CLL /HERE TO DISMISS THE INTERUPT
+
+ PCF
+/ RRB
+
+ TAD INTLNK
+ RAL
+ TAD INTACC
+ ION
+ JMP I 0
+
+INTACC, 0
+INTLNK, 0
+INTGLH, 0
+
+
+
+/
+/ NOW BEGINS THE GREAT UPDATE PROCEEDURE, FIRST FOR SHIP
+/ NUMBER ONE (THE DELTA SHAPED SHIP WHICH APPEARS ON
+/ THE LEFT AT THE START OF THE GAME). IF ALIVE THE STATUS
+/ WORD (INTWRD) IS TESTED FOR REQUESTS FOR LEFT TURN,
+/ RIGHT TURN, THRUST ON, AND LAUNCH PROJECTILE. THESE ACTIONS
+/ MAY OR MAY NOT BE ACTED UPON DEPENDING ON COUNTS AND FLAGS.
+/ WHEN THIS IS COMPLETE THE SAME OPERATION IS PERFORMED FOR
+/ NUMBER TWO.
+/
+
+ *400
+
+ONEUP, TAD ONEFLG /FIRST SEE IF IT'S IN NORMAL SPACE
+ SNA
+ JMP ONEOK /YES IT IS
+ IAC /NO, BUT IS IT JUST COMING OUT?
+ SNA
+ TAD ONEFIN /YES, THROW BACK IN IF ALREADY DESTROYED
+ DCA ONEFLG /OTHERWISE JUST COUNT ONE
+ JMP I ITWOUP /AND GO TO FIX UP NUMBER TWO
+
+ONEOK, TAD ONEOUT /IN NORMAL SPACE - IS IT EXPLODING?
+ SZA CLA
+ JMP ONEFIG /IF YES, ALLOW NO CONTROLS
+ TAD TWOFIN /HAS THE ENEMY BEEN VANQUISHED?
+ SZA CLA
+ JMS I ONEWN /YES, SIGNAL VICTORY
+ TAD INTWRD /NOW BEGIN TEST OF REQUEST
+ AND OP300 /LEFT AND RIGHT TURN TOGETHER MEAN HYPERSPACE!
+ TAD OM300 /TEST BITS 4 AND 5
+ SZA CLA
+ JMP ONELEF /NOPE, CONTINUE
+ CMA /YES, CALL HYPER WITH AC=-1 FOR NUMBER ONE
+ JMP I HYPER
+ONELEF, TAD INTWRD /REQUEST FOR LEFT TURN?
+ AND P200 /TEST BIT 4
+ SNA CLA
+ JMP ONERYT /NO
+ CLA CLL CMA /YES DECREMENT ANGLE
+ JMP ONEFIG
+
+ONERYT, TAD INTWRD /HOW ABOUT RIGHT TURN
+ AND P100 /TEST BIT 5
+ SZA CLA
+ IAC /YES, INCREMENT ANGLE
+
+ONEFIG, TAD ONETHE /PICK UP AND ADJUST ANGLE (MAYBE)
+ JMS I THEADJ /BRING BACK WITHIN LIMITS OF TRIG FUNCTIONS
+ DCA ONETHE /AND STORE
+ TAD ONETHE /FIND THEM TRIG FUNCTIONS
+ JMS I SINE /AND STORE ONCE AND FOR ALL
+ DCA ONESIN /IN THE APPROPRIATE PLACES
+ TAD ONETHE
+ JMS I COSINE
+ DCA ONECOS
+ TAD ONEOUT /DO NOT ALLOW THRUST IF EXPLODING
+ SZA CLA
+ JMP ONEVEL
+
+
+
+
+ONEMOV, TAD ACCFLG /ALLOW ANY VELOCITY INCREASE THIS CYCLE?
+ SZA CLA
+ JMP ONEVEL /NOPE
+ TAD INTWRD /YES, ANY REQUESTED?
+ AND P40 /TEST BIT 6
+ SNA CLA
+ JMP ONEVEL /NONE REQUESTED
+ TAD ONECOS /YES, ADD IN VELOCITY INCREMENT DEPENDING
+ TAD ONEVEY /ON ORIENTATION
+ JMS I VEESCL /BUT DO NOT ALLOW TO EXCEED MAXIMUM
+ DCA ONEVEY /AND STORE
+ TAD ONESIN /DO THE SAME FOR THE OTHER (X) COMPONENT
+ TAD ONEVEX
+ JMS I VEESCL
+ DCA ONEVEX
+
+
+
+ONEVEL, TAD ONEVEX /NOW UPDATE THE POSITION WITH THE
+ JMS I ISHFT /VELOCITY COMPONENTS DIVIDED BY 4
+ JMS I ISHFT /THIS MAINTAINS MAXIMUM RESOLUTION
+ TAD ONEPEX
+ DCA ONEPEX /IGNORE ANY OVERFLOW
+ TAD ONEVEY /DO THE SAME FOR Y COORDINATE
+ JMS I ISHFT /AND VELOCITY COMPONENT
+ JMS I ISHFT
+ TAD ONEPEY
+ DCA ONEPEY
+ TAD ONEOUT /DO NOT ALLOW PROJECTILE LAUNCH IF
+ SZA CLA /EXPLODING
+ JMP I ITWOUP
+
+
+
+
+ONELNC, TAD LNC1FG /OTHERWISE, SEE IF RELOAD IS FINISHED
+ SNA CLA
+ JMP .+3
+ ISZ LNC1FG /NO, CONTINUE RELOADING
+ JMP I ITWOUP /AND EXIT
+ TAD INTWRD /YES, READY TO LAUNCH, TRIGGER BEEN PULLED?
+ AND P20 /TEST BIT7
+ SNA CLA
+ JMP I ITWOUP /NO, WAIT FOR A BETTER SHOT
+ /.....I GUESS.....
+ TAD PROLIF /YES, SET CYCLE COUNT FOR THIS LAUNCH
+ DCA I AUTO16 /AUTO16 ALWAYS POINTS AT THE NEXT SLOT IN THE FILE
+ TAD ONEVEX /ADD SHIPS VELOCITY (SCALED OF COURSE)
+ JMS I ISHFT /TO ORIENTATION TO EXTABLISH X VELOCITY
+ JMS I RSHIFT /COMPONENT OF PROJECTILE
+ TAD ONESIN
+ JMS I RSHIFT /AND STICK IT IN THE FILE
+ DCA I AUTO16
+ TAD ONESIN /MOVE THE LAUNCH POINT OUTSIDE THE
+ CLL RTL /SHIP OF ORIGIN
+ TAD ONEPEX
+ DCA I AUTO16 /AND STORE X POSITION
+ TAD ONEVEY /NOW DO THE SAME FOR THE Y VELOCITY AND
+ JMS I ISHFT /POSITION
+ JMS I RSHIFT
+ TAD ONECOS
+ JMS I RSHIFT
+ DCA I AUTO16
+ TAD ONECOS
+ CLL RTL
+ TAD ONEPEY
+ DCA I AUTO16
+ TAD M200 /START RELOAD CYCLE
+ DCA LNC1FG
+ JMS I RESET1 /RESET AUTO16 TO NEXT HOLE
+
+ JMP I .+1 /NOW TO FIX IT UP WITH NUMBER TWO
+ITWOUP, TWOUP
+
+LNC1FG, 0 /PROJECTILE LAUNCH ENABLE
+
+OP300, 300 /HYPERSPACE REQUEST CODE BITS 4 AND 5
+OM300, -300
+ONEWN, ONEWIN /POINTER TO VICTORY MESSAGE
+
+
+
+/
+/ HERE BEGINS THE UPDATE PROCEEDURE FOR SHIP NUMBER TWO.
+/ OPERATION IS THE SAME AS FOR NUMBER ONE ABOVE.
+/
+
+ *600
+
+TWOUP, TAD TWOFLG /FIRST SEE IF IT'S IN NORMAL SPACE
+ SNA
+ JMP TWOOK /YES, CONTINUE
+ IAC /NO, BUMP COUNT AND TEST FOR REENTRY
+ SNA
+ TAD TWOFIN /IF RE-ENTERING THROW BACK OUT IF FINISHED
+ DCA TWOFLG /AND CONTINUE
+ JMP I IONEST
+
+TWOOK, TAD TWOOUT /HERE WHEN READY TO UPDATE IN NORMAL SPACE
+ SZA CLA /IS IT EXPLODING?
+ JMP TWOFIG /YES DO NOT ALLOW HYPERSPACE
+ TAD ONEFIN /DID WE JUST WIN?
+ SZA CLA
+ JMS I TWOWN /YES ENABLE END OF GAME MESSAGE
+ TAD INTWRD /TEST FOR HYPERSPACE REQUEST
+ AND OP14
+ TAD OM14 /BITS 8 AND 9 MUST BE SET
+ SNA CLA
+ JMP I HYPER /8 AND 9 SET. ENTER HYPER ROUTINE WITH AC=0
+ /FOR SHIP NUMBER 2
+TWOLEF, TAD INTWRD /TEST FOR LEFT TURN - BIT 8
+ AND P10
+ SNA CLA
+ JMP TWORYT /NOT SET
+ CLA CLL CMA /SET, DECREMENT TWOTHE BY 1 DEGREE
+ JMP TWOFIG /SKIP TEST FOR RIGHT TURN
+
+TWORYT, CLA CLL IAC RTL /TEST FOR RIGHT TURN - BIT 9
+ AND INTWRD
+ SZA CLA
+ IAC /IF SET INCREMENT TWOTHE BY 1 DEGREE
+
+TWOFIG, TAD TWOTHE /UPDTAE TWOTHE
+ JMS I THEADJ /BRING TO WITHIN LIMITS OF SINE,COSINE
+ DCA TWOTHE /AND STORE
+ TAD TWOTHE
+ JMS I SINE /CALCULATE SINE AND COSINE FUNCTIONS
+ DCA TWOSIN /AND STORE IN DATA TABLE
+ TAD TWOTHE
+ JMS I COSINE
+ DCA TWOCOS
+ TAD TWOOUT /DO NOT ALLOW VELOCITY CHANGE IF EXPLODING
+ SZA CLA
+ JMP TWOVEL
+
+
+
+
+TWOMOV, TAD ACCFLG /NOW FOR ACCELERATION. TEST TO SEE IF ALLOWED
+ SZA CLA /DURING THIS UPDATE CYCLE
+ JMP TWOVEL /NOPE
+ CLL IAC RAL /YES, TEST FOR BIT 2 SET
+ AND INTWRD
+ SNA CLA
+ JMP TWOVEL /NOT SET
+
+ TAD TWOSIN /UPDATE X VELOCITY COMPONENT BY SINE OF
+ TAD TWOVEX /ANGLE OF ORIENTATION
+ JMS I VEESCL /AND SCALE TO NOT EXCEED MAX
+ DCA TWOVEX /UPDATE Y COMPONENT WITH COSINE
+
+ TAD TWOCOS
+ TAD TWOVEY
+ JMS I VEESCL
+ DCA TWOVEY
+
+
+
+TWOVEL, TAD TWOVEX /NOW UPDATE THE POSITION WITH THE VELOCITY
+ JMS I ISHFT /COMPONENTS/16
+ JMS I ISHFT
+ TAD TWOPEX
+ DCA TWOPEX
+ TAD TWOVEY
+ JMS I ISHFT
+ JMS I ISHFT
+ TAD TWOPEY
+ DCA TWOPEY
+ TAD TWOOUT
+ SZA CLA
+ JMP I IONEST
+
+
+
+
+TWOLNC, TAD LNC2FG /NOW CHECK FOR PROJECTILE LAUNCH. FIRST
+ SNA CLA /TEST TO SEE IF RELOAD COMPLETE
+ JMP .+3
+ ISZ LNC2FG /NO, COUNT ONE CYCLE AND EXIT
+ JMP I IONEST
+ IAC /YES, TEST TRIGGER BIT 11
+ AND INTWRD
+ SNA CLA
+ JMP I IONEST /NOT SET, HELL WITH IT
+
+ TAD PROLIF /OK, SET PROJECTILE LIFE
+ DCA I AUTO16 /AUTO16 IS ALWAYS POINTING AT THE NEXT SLOT
+ TAD TWOVEX /ADD SHIPS VELOCITY
+ JMS I ISHFT /(ADJUSTED)
+ JMS I RSHIFT
+ TAD TWOSIN /TO THAT OF PROJECTILE - AGAIN X COMPONENT
+ JMS I RSHIFT /FROM SINE OF ANGLE OF ORIENTATION
+ DCA I AUTO16
+ TAD TWOSIN /SET INITIAL POSITION TO BE JUST AHEAD
+ CLL RTL /OF THE SHIP
+ TAD TWOPEX /X COMPONENT
+ DCA I AUTO16
+ TAD TWOVEY /NOW THE Y COMPONENTS FROM Y VELOCITY
+ JMS I ISHFT /Y POSITION AND COSINE
+ JMS I RSHIFT
+ TAD TWOCOS
+ JMS I RSHIFT
+ DCA I AUTO16
+ TAD TWOCOS
+ CLL RTL
+ TAD TWOPEY
+ DCA I AUTO16
+ TAD M200
+ DCA LNC2FG /200 CYCLES OF RELOAD
+ JMS I RESET1 /DRINK LEADEN DEATH, NUMBER ONE!
+
+ JMP I .+1 /FINAL EXIT TO DISPLAY FILE CALCULATIONS
+IONEST, ONESET
+
+LNC2FG, 0 /RELOAD COUNT
+
+OP14, 14 /HYPERSPACE CODE
+OM14, -14
+TWOWN, TWOWIN
+
+
+
+/
+/ HERE BEGINS THE DISPLAY CALCULATIONS FOR THE TWO SHIPS. AT
+/ THIS POINT ONLY THE POSITION AND ORIENTATION OF EACH VESSEL
+/ IS ONF INTEREST SINCE THE VELOCITY AND ALL THAT HAVE ALREADY
+/ BEEN TAKEN CARE OF. FOR THE BOTH SHIPS THE DISPLAY FILES ARE
+/ CALCULATED AS A SERIES OF PAIRS OF X,Y COORDINATES. BETWEEN
+/ EACH PAIR OF POINTS A FOUR POINT VECTOR WILL BE DRAWN. THE
+/ ACTUAL COORDINATES ARE CALCULATED AS DISPLACEMENTS
+/ FROM THE CENTRAL PSOTION OF THE SHIP, TAKING INTO ACCOUNT THE
+/ ANGLE OF ORIENTATION. THE FORMULAS FOLLOWED ARE:
+/
+/ X(POINT)=X(BASE)+X(REL)*COS[THE]+Y(REL)*SINE[THE]
+/
+/ Y(POINT)=Y(BASE)+Y(REL)*COS[THE]-X(REL)*SINE[THE]
+/
+/ WHERE SINE[THE] AND COS[THE] ARE THE FUNCTIONS OF THE
+/ ANGLE OF ORIENTATION, X(BASE) AND Y(BASE) ARE THE
+/ COORDINATES OF THE SHIPS POSITION AND X(REL) AND Y(REL)
+/ CORRESPOND TO DISPLACEMENT PAIRS DEPENDING ON THE SHAPE
+/ OF THE FIGURE. ALL X AND Y RELS LIE WITHIN THE RANGE 0-3 AND
+/ THERE FORE ALL NECESSARY DISPLACEMENTS FROM BASE COORDINATES
+/ MAY BE CALCULATEDFROM DIFFERENT COMBINATIONS OF T10SIN, T20COS
+/ ETC. THESE VALUES ARE CALCULATED BY A CALL TO POSCAL WITH THE SINE
+/ AND COSINE OF THE ANGLE OF INTEREST IN CALSIN AND CALCOS.
+/
+/ FOLLOWING THIS METHOD ANY FIGURE DESCRIBABLE WITH A 7 BY 7
+/ MATRIX OF POINTS MAY BE QUICKLY CALCULATED.
+/
+/ BEGINNING AT ONESET DIFFERENT DISPLACEMENT PAIRS ARE CALCULATED
+/ AND DEPOSITIED THROUGH AUTO10 TO FORM THE DISPLAY FILE FOR SHIP NUMBER ONE.
+/
+
+
+ *1000
+
+ONESET, CLA CLL /BEGIN DISPLAY FILE FOR NUMBER ONE
+ TAD ONEFLG /DONT BOTHER IF NOT IN NORMAL SPACE
+ SZA CLA
+ JMP I ITWOST
+ TAD ONESIN /SET UP FOR MATRIX COMPONENT CALCULATIONS
+ DCA CALSIN
+ TAD ONECOS
+ DCA CALCOS
+ JMS I CALPOS /CALL THE CALCULATOR
+
+/
+/ CONSIDER THE 7 BY 7 MATRIX OF DISPLACEMENT POINTS WITH THE
+/ CENTER AT 0,0 CORRESPONDING TO THE SHIPS POSITION. A SERIES
+/ OF POINTS IS NOW DESCRIBED AROUND THIS CENTER USING THE
+/ MULTIPLES OF THE TRIG FUNCTIONS JUST CALCULATED
+/ SO THAT ANY POINT ON THE OUTLINE IS DESCRIBABLE AS X,Y
+/ DISPLACED BY X,Y OF THE SHIP ITSELF
+/
+
+ TAD ONEFIL /SET UP AUTO10 AS THE DISPLAY FILE
+ DCA AUTO10 /POINTER
+ TAD ONEPEX /THE FIRST POINT OF THE OUTLINE IS
+ TAD T30SIN
+ DCA I AUTO10 / 0,3 OR TOP CENTER
+ TAD ONEPEY
+ TAD T30COS
+ DCA I AUTO10
+
+ TAD T10COS
+ CIA /THE SECOND IS
+ TAD ONEPEX
+ DCA I AUTO10 / -1,0
+ TAD T10SIN /OR JUST LEFT OF DEAD CENTER
+ TAD ONEPEY /AND SO ON
+ DCA I AUTO10
+
+ TAD T30SIN
+ TAD T30COS /THE THIRD POINT IS
+ CIA
+ TAD ONEPEX / -3,-3
+ DCA I AUTO10
+ TAD T30COS /OR BOTTOM LEFT HAND CORNER
+ CIA
+ TAD T30SIN
+ TAD ONEPEY
+ DCA I AUTO10
+
+
+
+
+ TAD T10SIN
+ CIA /FOURTH POINT
+ TAD ONEPEX
+ DCA I AUTO10 / 0,-1
+ TAD T10COS
+ CIA /OR JUST BELOW CENTER
+ TAD ONEPEY
+ DCA I AUTO10
+
+FLAM1, TAD INTWRD /TEST FOR POWER ON. IF ON, DRAW THE
+ AND P40 /FLAME WITH AN EXTRA POINT SOME
+ SNA CLA /DISTANCE DIRECTLY BELOW THE SHIP
+ JMP ONECON /POWER NOT ON - CONTINUE
+ TAD ONEOUT /DO NOT ALLOW IF EXPLODING
+ SZA CLA
+ JMP ONECON
+
+ TAD ONFG1 /USE ONFG1 TO TURN THE FLAME ON AND
+ SNA /OFF TO MAKE IT FLICKER. DISPLAY THE
+ CLA CLL CMA RAL /FLAME ONE TIME OUT OF THREE
+ DCA ONFG1
+
+ ISZ ONFG1
+ JMP ONECON /ONE OUT OF THREE TIMES THIS WILL SKIP
+
+ TAD ONFG2 /VARY ALSO THE LENGHT OF THE FLAME
+ CMA /WITH LONG SHORT LONG SHORT
+ DCA ONFG2
+
+ TAD ONFG2 /TIP OF FLAME AT EITHER
+ SNA CLA
+ TAD T10SIN / 0,-4 OR
+ TAD T30SIN / 0,-3
+ CIA
+ TAD ONEPEX
+ DCA I AUTO10
+ TAD ONFG2
+ SNA CLA
+ TAD T10COS
+ TAD T30COS
+ CIA
+ TAD ONEPEY
+ DCA I AUTO10
+
+ TAD T10SIN
+ CIA
+ TAD ONEPEX /RETURN DISPLAY TO 0,-1
+ DCA I AUTO10
+ TAD T10COS
+ CIA
+ TAD ONEPEY
+ DCA I AUTO10
+ CLA CLL CMA RAL /ADD -2 TO POINT COUNT
+
+
+
+
+ONECON, TAD M6 /SET POINT COUNT TO -6 OR -8
+ DCA ONECNT
+
+ TAD T30SIN /CONTINUE WITH DISPLAY FILE - THIS POINT
+ CIA
+ TAD T30COS / AT 3,-3
+ TAD ONEPEX /
+ DCA I AUTO10 /OR LOWER RIGHT HAND CORNER
+ TAD T30SIN
+ TAD T30COS
+ CIA
+ TAD ONEPEY
+ DCA I AUTO10
+
+ TAD T10COS /NEXT
+ TAD ONEPEX /
+ DCA I AUTO10 / 1,0
+ TAD T10SIN /
+ CIA / OR JUST RIGHT OF CENTER
+ TAD ONEPEY
+ DCA I AUTO10
+
+ TAD T30SIN /FINALLY BACK TO
+ TAD ONEPEX /
+ DCA I AUTO10 / 0,3
+ TAD T30COS /
+ TAD ONEPEY / TOP CENTE
+ DCA I AUTO10
+
+ JMP I ITWOST /NOW FOR NUMBER TWO
+ITWOST, TWOSET
+
+ONFG1, 0 /USED TO COUNT FLICKERS
+ONFG2, 0 /SHORT OR LONG FLAG
+
+
+
+/
+/ HERE BEGINS THE DISPLAY FILE GENERATOR FOR SHIP TWO.
+/ IT WORKS JUST LIKE THE ONE FOR NUMBER ONE BUT WITH
+/ DIFFERENT DISPLACEMENT PAIRS AND TWO EXTRA POINTS
+/
+
+ *1200
+
+TWOSET, CLA CLL /DONT BOTHER IF NOT IN NORMAL SPACE
+ TAD TWOFLG
+ SZA CLA
+ JMP I IFILDS
+ TAD TWOSIN /SET UP TO HAVE DISPLACEMENT INCREMENTS
+ DCA CALSIN /CALCULATED
+ TAD TWOCOS
+ DCA CALCOS
+ JMS I CALPOS
+
+ TAD TWOFIL /SET AUTO10 TO POINT TO SECOND DISPLAY
+ DCA AUTO10 /FILE
+ TAD T30SIN /FIRST POINT AT
+ TAD TWOPEX /
+ DCA I AUTO10 / 0,3
+ TAD T30COS /
+ TAD TWOPEY / OR TOP CENTER
+ DCA I AUTO10
+
+ TAD T20COS
+ CIA
+ TAD T20SIN
+ TAD TWOPEX
+ DCA I AUTO10
+ TAD T20SIN
+ TAD T20COS /SECOND POINT
+ TAD TWOPEY / -2,2
+ DCA I AUTO10
+
+ TAD T20COS /THIRD POINT
+ CIA / -2,0
+ TAD TWOPEX
+ DCA I AUTO10
+ TAD T20SIN
+ TAD TWOPEY
+ DCA I AUTO10
+
+
+
+ TAD T20COS
+ TAD T30SIN
+ CIA
+ TAD TWOPEX /FOURTH POINT
+ DCA I AUTO10 / -2,-3
+ TAD T30COS
+ CIA
+ TAD T20SIN
+ TAD TWOPEY
+ DCA I AUTO10
+
+
+
+
+ TAD T20SIN
+ CIA /NEXT
+ TAD TWOPEX / 0,-2
+ DCA I AUTO10
+ TAD T20COS
+ CIA
+ TAD TWOPEY
+ DCA I AUTO10
+
+FLAM2, CLA CLL IAC RAL /NOW THE FLAME BIT. CHECK FOR POWER ON
+ AND INTWRD
+ SNA CLA
+ JMP TWOCON /NO, FORGET IT
+ TAD TWOOUT /NOT ALLOWED IF EXPLODING
+ SZA CLA
+ JMP TWOCON
+
+ TAD TWFG1 /SET THE 1-3 FLICKER AS WITH #1
+ SNA
+ CLA CLL CMA RAL
+ DCA TWFG1
+
+ ISZ TWFG1 /ALSO THE LENGHT VARIATION
+ JMP TWOCON
+
+ TAD TWFG2 /EVERY OTHER TIME LONG
+ CMA
+ DCA TWFG2
+ /FLAME TIP AT EITHER
+ TAD TWFG2 / 0,-3
+ SNA CLA /OR
+ TAD T20SIN / 0,-5
+ TAD T30SIN
+ CIA
+ TAD TWOPEX
+ DCA I AUTO10
+ TAD TWFG2
+ SNA CLA
+ TAD T20COS
+ TAD T30COS
+ CIA
+ TAD TWOPEY
+ DCA I AUTO10
+
+ TAD T20SIN /NOW BACK UP TO THE SHIP
+ CIA
+ TAD TWOPEX
+ DCA I AUTO10
+ TAD T20COS
+ CIA
+ TAD TWOPEY
+ DCA I AUTO10
+
+ CLA CLL CMA RAL /ADD -2 TO POINT COUNT
+
+
+
+
+TWOCON, TAD M10 /SET POINT COUNT TO -8 OR -10
+ DCA TWOCNT
+
+ TAD T30SIN /CONTINUE WITH DISPLAY FILE
+ CIA /NEXT POINT AT 2,-3
+ TAD T20COS
+ TAD TWOPEX
+ DCA I AUTO10
+ TAD T30COS
+ TAD T20SIN
+ CIA
+ TAD TWOPEY
+ DCA I AUTO10
+
+
+
+ TAD T20COS /NEXT POINT
+ TAD TWOPEX /
+ DCA I AUTO10 / 2,0
+ TAD T20SIN
+ CIA
+ TAD TWOPEY
+ DCA I AUTO10
+
+ TAD T20COS /AND THE NEXT AT
+ TAD T20SIN
+ TAD TWOPEX / 2,2
+ DCA I AUTO10
+ TAD T20SIN
+ CIA
+ TAD T20COS
+ TAD TWOPEY
+ DCA I AUTO10
+
+ TAD T30SIN
+ TAD TWOPEX
+ DCA I AUTO10
+ TAD T30COS /AND THE LAST AT
+ TAD TWOPEY /
+ DCA I AUTO10 / 0,3
+
+ JMP I IFILDS /NOW TO DISPLAY THE WHOLE MESS
+IFILDS, FILDIS
+
+TWFG1, 0 /FLIK THE FLAME
+TWFG2, 0 /LONG OR SHORT
+
+
+
+/
+/ HERE TO DISPLAY THE TWO SHIPS. CHECK FIRST FOR COLLISION
+/ AND THEN SET THE TWO PAIRS OF COORDENATES FOR THE END
+/ POINTS AND CALL THE "VECTOR GENERATOR" TO DRAW THE DOTS
+/ IN BETWEEN. WHEN THE COUNT OVERFLOWS DO THE SAME FOR
+/ NUMBER TWO. THEN EXIT TO DISPLAY ALL THE PROJECTILES.
+/
+
+ *1400
+
+FILDIS, CLA CLL /ALL SET TO GO
+ JMS I COLIDE /TEST FOR COLLISION FIRST
+/ DSB 1 /IF NO COLLISION
+ TAD ONEFLG /SKIP NUMBER ONE IF NOT IN NORMAL
+ SZA CLA /SPACE
+ JMP TWODIS
+
+ TAD ONEFIL /SET UP POINTERS TO DISPLAY FILE
+ DCA AUTO10 /FOR NUMBER ONE
+ TAD ONECNT /ALONG WITH VECTOR COUNT
+ DCA AUTO11
+ TAD I AUTO10 /SET OUT THE FIRST POINT PAIR
+ DCA XONEDS
+ TAD I AUTO10
+ DCA YONEDS
+ TAD ONEOUT /NORMAL DISPLAY OR EXPLOSION?
+ SZA CLA
+ JMP I IONEEX /GO ELSE WHERE FOR EXPLOSION
+
+FILONE, TAD I AUTO10 /STEP TO NEXT PAIR OF POINTS
+ DCA XTWODS /SET X AND Y TO NEW POINT
+ TAD I AUTO10
+ DCA YTWODS
+ JMS I VECTOR /CALL THE DOT DRAWING MACHINE
+ ISZ AUTO11
+ SKP /COUNT
+ JMP TWODIS /DO NUMBER TWO ON OVERFLOW
+ TAD XTWODS /SWAP POINTS FOR NEXT PAIR
+ DCA XONEDS
+ TAD YTWODS /THE GENERATOR DRAWS FROM ONE
+ DCA YONEDS /TOWARDS TWO
+ JMP FILONE
+
+
+
+
+TWODIS, TAD TWOFLG /HERE TO DO NUMBER TWO
+ SZA CLA /BUT NOT IF IN HYPER SPACE
+ JMP I IPRODS
+
+ TAD TWOFIL /SET UP FILE POINTER AS IN ONE
+ DCA AUTO10
+ TAD TWOCNT /AND THE COUNT
+ DCA AUTO11
+ TAD I AUTO10 /I SUPPOSE THIS COULD BE A SUBROUTINE TOO
+ DCA XONEDS
+ TAD I AUTO10
+ DCA YONEDS
+ TAD TWOOUT /IS IT EXPLODING?
+ SZA CLA
+ JMP I ITWOEX /YES, HOW EXCITING
+
+TWDLOP, TAD I AUTO10 /NO HOW DULL, STICK IN NEXT PAIR OF
+ DCA XTWODS /POINTS
+ TAD I AUTO10
+ DCA YTWODS /AND CALL THE VECTOR SEQUENCE
+ JMS I VECTOR
+ ISZ AUTO11
+ JMP .+3
+
+ JMP I .+1 /WHEN COUNT OVERFLOWS GO ON TO
+IPRODS, PRODIS /DO THE PROJECTILE THING
+
+ TAD XTWODS /OTHERWISE SWAP ON TO THE NEXT PAIR
+ DCA XONEDS /OF POINTS
+ TAD YTWODS
+ DCA YONEDS
+ JMP TWDLOP
+
+COLIDE, COLLID
+IONEEX, ONEEXP
+ITWOEX, TWOEXP
+
+
+
+/
+/ THIS IS THE SO CALLED "VECTOR GENERATOR" WHICH DRAWS A
+/ SERIES OF DOTS FROM XONEDS,YONEDS TO XTWODS,YTWODS.
+/ THE COORDINATE COMPONENTS ARE DIVIDED INTO FOURTHS AND
+/ FOUR DOTS DRAWN ON THE SCOPE SCREEN. NOTE THAT NO DOT
+/ IS DRAWN AT XONEDS,YONEDS. THIS IS COMPENSATED FOR ELSEWHERE.
+/
+
+DISPLY, 0 /ENTER TO DRAW A FOUR POINT VECTOR
+ CLA
+ TAD XONEDS /FROM XONEDS,YONEDS
+ CIA /TO XTWODS,YTWODS
+ TAD XTWODS /DIVIDE COORDINATE DIFERENCES INTO
+ JMS DISHFT /FOURTHS
+ DCA DIXTEM /AND STORE INCREMENT
+ TAD YONEDS
+ CIA
+ TAD YTWODS
+ JMS DISHFT /FOURTHS
+ DCA DIYTEM
+ TAD M4 /FOR FOUR DOTS
+ DCA DISCNT
+
+DISLOP, TAD XONEDS /ADD INCREMENT TO CURRENT X AND Y
+ TAD DIXTEM
+ DCA XONEDS /NOTE THAT THIS ROUTINE DESTROYS
+ TAD YONEDS /XONEDS AND YONEDS
+ TAD DIYTEM
+ DCA YONEDS
+ TAD XONEDS
+/ RTR /DIVIDE BY 8 TO FIT SCREEN SIZE
+/ RAR
+ DXC DXL /SET X VALUE
+ CLA
+ TAD YONEDS /DO THE SAME FOR Y
+/ RTR
+/ RAR
+ DYC DYL DIS /AT LAST SOMETHING TO SEE!!
+ CLA
+ ISZ DISCNT /DONE YET?
+ JMP DISLOP /NOPE
+ JMP I DISPLY /YUP
+
+
+DISHFT, 0 /A GENERALIZED SHIFT ROUTINE CALLED
+ CLL /FROM EVERYWHERE TO DIVIDE THE
+ SPA /AC BY FOUR WITH AN ASR RIGHT
+ CML IAC /NOTE THAT NEGATIVE NUMBERS ARE
+ RAR /ROUNDED UPWARDS (TOWARD ZERO)
+ CLL /TO MAKE IT COME OUT RIGHT
+ SPA
+ CML IAC /EVEN SO THERE ARE SOME ROUNDING ERRORS
+ RAR /SOMEWHERE. SO MUCH FOR 12 BIT MACHINES
+ JMP I DISHFT
+
+
+
+/
+/ HERE TO DISPLAY ALL THE PROJECTILES AND TEST FOR HITS.
+/ THE PROJECTILE DISPLAY FILE IS SEARCHED FOR PROJECTILES WITH
+/ NON-ZERO COUNTS AND WHEN ONE IS FOUND THE POSITION IS
+/ UPDATED BY THE VELOCITY, THE POINT DISPLAYED AND TESTED FOR
+/ A HIT.
+/
+
+ *1600
+
+PRODIS, CLA CLL / BEGIN DISPLAY OF THE PROJECTILES
+ TAD BUFST /POINT TO BEGINNING OF DISPLAY FILE
+ DCA BUFTMP
+/ DSB 2 /SET EXTRA BRIGHT FOR SINGLE POINTS
+
+PROLOP, TAD I BUFTMP /PICK UP NEXT COUNT
+ SNA
+ JMP EXPIRE /THIS ONE IS DEAD - GO TO THE NEXT
+ IAC /INCREMENT COUNT AND REPLACE
+ DCA I BUFTMP
+ ISZ BUFTMP /BUMP POINTER TO X VELOCITY
+ TAD I BUFTMP
+ ISZ BUFTMP /THEN TO XPOSITION AND UPDATE X POSITION
+ TAD I BUFTMP /WITH THE VELOCITY WHICH IS CONSTANT
+ DCA I BUFTMP
+ TAD I BUFTMP
+ DCA PROX /AND STORE X POSITION FOR DISPLAY AND TEST
+ ISZ BUFTMP /NOW TO Y POSITION AND VELOCITY
+ TAD I BUFTMP
+ ISZ BUFTMP
+ TAD I BUFTMP /SAME LITTLE GAME
+ DCA I BUFTMP
+ TAD I BUFTMP
+ DCA PROY /STORE THE NEW Y VALUE
+
+ TAD PROX /DISPLAY THE POINT WITH
+/ RTR /THE SAME SHIFT AS FOR THE SHIPS
+/ RAR /FOR THE SMALL SCREEN
+ DXC DXL
+ CLA
+ TAD PROY
+/ RTR /
+/ RAR
+ DYC DYL DIS /THERE IT IS!!
+ CLA
+ JMS I CHKOUT /TEST FOR A HIT
+ ISZ BUFTMP /MOVE POINTER ON AND TEST FOR END
+ TAD BUFTMP /OF BUFFER
+ TAD BUFLIM
+ SZA CLA
+ JMP PROLOP /NOT AT END - CONTINUE
+
+
+/
+/ HERE AT THE END OF THE PROJECTILE DISPLAY. IF THE GAMOVR
+/ FLAG IS SET, GO ON TO THE MESSAGE DISPLAY - VICTORY LAP
+/ SECTION. OTHERWISE PICK UP THE REMAINING CLOCK COUNT
+/ TO GIVE THE FANS SOMETHING TO LOOK AT, AND MOVE THE
+/ ELECTRON BEAM TO A LOWER CORNER. THE COUNT DISPLAYED
+/ IN THE AC IS THE NUMBER OF 100 USEC CLOCK TICKS REMAINING
+/ WHEN THIS CODE IS REACHED BEFORE THE NEXT UPDATE WOULD
+/ BEGIN. TURNS OUT THAT ROUGHLY 2/3 OF THE CPU IS LEFT
+/ OVER SHOULD ANYONE WANT TO DO ANYTHING VERY FANCY.
+/
+
+
+FINISH, TAD GAMOVR /IS THIS THE VICTORY LAP OR WHAT?
+ SZA CLA
+ JMP I ENDGAM /YES, GO TO PUT UP THE MESSAGE
+/ TAD M400 /MOVE THE BEAM OFF SCREEN
+/ DYC DYL
+ CLA CLL
+/ DXC DXL
+ TAD INTCNT /PICK UP THE COUNT
+ CIA
+ JMP .
+
+ENDGAM, JOBLOP
+
+
+EXPIRE, TAD BUFTMP /HERE TO ADVANCE THE BUFFER
+ TAD P5 /POINTER TO THE NEXT PROJECTILE
+ DCA BUFTMP /UNLESS THE END
+ TAD BUFTMP /OF THE BUFFER
+ TAD BUFLIM /IS REACHED
+ SZA CLA /IN WHICH CASE
+ JMP PROLOP /IT
+ JMP FINISH /QUITS
+
+BUFST, DISBUF+101
+BUFLIM, -DISBUF-175
+CHKOUT, CHECK
+
+RESE1, 0 /THIS IS CALLED TO SET THE POINTER
+ TAD MRES /(AUTO16) TO THE NEXT FREE SLOT
+ DCA RESCNT /FOR A PROJECTILE LAUNCH. 12 POSSIBLE
+
+RESLOP, TAD RESPNT /MOVE THE POINTER TO THE NEXT SLOT
+ TAD P5
+ DCA RESPNT
+ TAD RESPNT /RESTE IF AT END OF BUFFER
+ TAD BUFLIM
+ SZA CLA
+ JMP RESCON
+ TAD BUFST
+ DCA RESPNT
+
+RESCON, TAD I RESPNT /FIND A HOLE YET?
+ SNA CLA
+ JMP RESFND /YES, SET UP AUTO16
+ ISZ RESCNT /NO COUNT
+ JMP RESLOP /AND TRY AGAIN
+ HLT /NO HOLES AT ALL?
+
+RESFND, CMA /BACK THE POINTER FOR AUTO INDEXING
+ TAD RESPNT
+ DCA AUTO16
+ JMP I RESE1
+
+MRES, -14
+RESCNT, 0
+RESPNT, 0
+
+SETBUF, 0
+ CMA /THIS ROUTINE IS CALLED FROM THE
+ TAD BUFST /STARTING SEQUENCE TO INITIALIZE ALL
+ DCA AUTO16 /THE BUFFER POINTERS AND SO ON
+ TAD BUFST
+ DCA BUFTMP
+ TAD BUFST
+ DCA RESPNT
+ TAD BUFST
+ DCA SETPNT
+SETLOP, DCA I SETPNT
+ ISZ SETPNT
+ TAD SETPNT
+ TAD BUFLIM
+ SZA CLA
+ JMP SETLOP
+ JMP I SETBUF
+
+SETPNT, 0
+
+
+
+/
+/ THIS HERE NOW THING CHECKS THE COORDINATES OF THE MOST RECENTLY
+/ DISPLAYED PROJECTILE AGAINST THOSE OF THE SHIPS ON THE SCREEN.
+/ IF WITH A COLLISION LIMIT A HIT IS RECORDED AND THE LIFE
+/ COUNT OF THE PROJECTILE ZEROED TO REMOVE IT. A HIT SHIP
+/ IS SUITABLY FLAGGED
+/
+
+ *2000
+
+CHECK, 0 /HERE TO TEST FOR A PROJECTILE HIT
+ TAD ONEFLG /CANT HIT SOMETHING IN HYPERSPACE
+ SZA CLA
+ JMP CHECK2
+ TAD ONEOUT /OR SOMETHING THAT'S BEEN HIT
+ SZA CLA
+ JMP CHECK2
+
+ TAD PROX /CHECK X COORDINATES OF SHIP ONE
+ CIA /AND PROJECTILE
+ TAD ONEPEX /THIS SORT OF THING IS WHY THE
+ SPA /COORDINATES HAVE TO BE MAINTAINED TO 12
+ CIA /BITS
+ TAD LIMIT /CLOSE ENOUGH?
+ SMA CLA
+ JMP CHECK2 /IF X ISN' CLOSE ENOUGH THEN NO HIT
+ TAD PROY /X WAS CLOSE ENOUGH, HOW ABOUT Y?
+ CIA
+ TAD ONEPEY
+ SPA
+ CIA
+ TAD LIMIT
+ SMA CLA
+ JMP CHECK2 /NO HIT
+
+ TAD MEXP /DEPOSIT EXPLOSION COUNT IN ONEOUT
+ DCA ONEOUT /ALL THAT IS NECESSARY
+ JMS CUTOUT /REMOVE PROJECTILE
+
+
+
+
+CHECK2, TAD TWOFLG /NO HIT ON NUMBER ONE, TRY NUMBER TWO
+ SZA CLA
+ JMP I CHECK /BUT NOT IF IN HYPERSPACE
+ TAD TWOOUT /OR IF ALREADY HIT
+ SZA CLA
+ JMP I CHECK
+
+ TAD PROX /CHECK X'S FIRST
+ CIA
+ TAD TWOPEX
+ SPA /GET ABSOLUTE VALUE OF DIFFERENCE
+ CIA
+ TAD LIMIT /AND TEST MAGNITUDE AGAINST PROXIMITY
+ SMA CLA /LIMIT
+ JMP I CHECK /NOWHERE NEAR CLOSE
+
+ TAD PROY /NYAH, NYAH
+ CIA /TRY THE Y'S
+ TAD TWOPEY
+ SPA
+ CIA /ABSOLUTE VALUE OF DIFFERENCE
+ TAD LIMIT
+ SMA CLA
+ JMP I CHECK /CLEAN MISS!
+
+ TAD MEXP /HIT ON TWO - END EVERYTHING BY SETTING
+ DCA TWOOUT /TWOOUT TO NON-ZERO EXPLOSION COUNT
+ JMS CUTOUT
+ JMP I CHECK /EXIT AFTER DESTOYING PROJECTILE
+
+LIMIT, -120 /PROXIMITY LIMIT FOR WHAT CONSTITUTES A HIT
+
+CUTOUT, 0 /THIS ROUTINE ZEROES OUT THE MOST RECENTLY
+ TAD M4 /DISPLAYED PROJECTILE BY ZEROEING THE
+ TAD BUFTMP /COUNT
+ DCA CUTPNT
+ DCA I CUTPNT
+ JMP I CUTOUT
+
+CUTPNT, 0
+
+
+
+/
+/ THIS ROUTINE IS CALLED TO TEST FOR A COLLISION BETWEEN THE
+/ TWO SHIPS. THE COORDINATES OF BOTH ARE COMPARED
+/ AND IFF SUFFICIENTLY CLOSE BOTH ARE DESTROYED BY SETTING
+/ THEIR EXPLOSION COUNTS NON-ZERO.
+/
+
+
+COLLID, 0 /HERE TO TEST FOR COLLISION
+ TAD ONEFLG /NO TEST IF EITHER SHIP IS IN
+ SZA CLA /HYPERSPACE OR EXPLODING
+ JMP I COLLID
+ TAD TWOFLG
+ SZA CLA
+ JMP I COLLID
+ TAD ONEOUT
+ SZA CLA
+ JMP I COLLID
+ TAD TWOOUT
+ SZA CLA
+ JMP I COLLID
+
+ TAD ONEPEX /BOTH SHIPS AVAILABLE FOR COLLISION
+ CIA /CHECK X COORDINATES FIRST
+ TAD TWOPEX
+ SPA /GET ABSOLUTE VALUE OF DIFFERENCE
+ CIA
+ TAD COLLIM /CLOSE ENOUGH?
+ SMA CLA
+ JMP I COLLID /NOPE, FORGET IT
+
+ TAD ONEPEY /YES, NOW TRY THE Y COORDINATES
+ CIA
+ TAD TWOPEY
+ SPA
+ CIA /GET MAGNITUDE ONLY
+ TAD COLLIM
+ SMA CLA /CLOSE ENOUGH?
+ JMP I COLLID
+ TAD MEXP /YES, SET BOTH EXPLOSION COUNTS
+ DCA ONEOUT
+ TAD MEXP
+ DCA TWOOUT
+ JMP I COLLID
+
+COLLIM, -300
+
+
+/
+/ THIS ROUTINE IS CALLED TO SET ONE OF THE TWO SHIPS INTO
+/ HYPERSPACE. ON ENTRY THE AC=-1 FOR SHIP #1, 0 FOR SHIP
+/ NUMBER 2. THE LOCATION CLOCK IS USED FOR A RANDOM
+/ ADDRESS POINTER FROM WHICH WILL BE DRAWN THE
+/ VARIOUS PARAMETERS FOR REENTRY.
+/
+
+ *2200
+
+HYPSET, DCA RTNFLG /HERE WITH AC=-1 OR 0
+ TAD RTNFLG /SET UP LIST POINTER
+ SZA CLA
+ TAD ONEDIF /TO APPROPRIATE SHIP FILE
+ TAD TWOLST
+ DCA AUTO15
+
+ CLCA /SET UP "RANDOM NUMBER GENERATOR"
+ /USE CLOCK COUNTER FOR THAT PURPOSE
+ DCA AUTO17
+ TAD I AUTO17 /PICK UP FIRST THE AMOUNT OF TIME
+ AND TIMOUT /OUT OF NOMAL SPACE LIMITED TO -777
+ CIA /UPDATE CYCLES ( ABOUT 15 SECONDS)
+ DCA I AUTO15 /AND STORE IN ONEOUT OR TWO OUT
+
+ TAD I AUTO17 /THE NEXT RANDOM NUMBER BECOMES THE
+ JMS I THEADJ /ANGLE OR ORIENTATION ON REENTRY
+ DCA I AUTO15
+ TAD I AUTO17 /AND THE NEXT BECOMES THE X VELOCITY
+ JMS VEESET /COMPONENT
+ DCA I AUTO15
+ TAD I AUTO17 /AND THEN THE Y COMPONENT
+ JMS VEESET
+ DCA I AUTO15
+ TAD I AUTO17
+ DCA I AUTO15
+
+ TAD I AUTO17
+ DCA I AUTO15
+
+ TAD I AUTO17 /FINALLY SEE IF RETURN WILL BE SUCCESSFLY
+ AND TIMOUT
+ TAD MHYP /ABOUT 3/4 CHANCE
+ SMA CLA
+ JMP HYPRET /OK
+ TAD RTNFLG /THIS IS THE ONE TIME IN FOUR. SET
+ SZA CLA /UP FOR EXPLOSION ON REENTRY
+ TAD ONEDIF
+ TAD OUTLOC
+ DCA VEESET
+ TAD MEXP
+ DCA I VEESET
+
+HYPRET, ISZ RTNFLG
+ JMP I TWORTN
+ JMP I ONERTN
+
+TIMOUT, 777
+ONEDIF, ONEFLG-TWOFLG
+TWOLST, TWOFLG-1
+RTNFLG, 0
+ONERTN, TWOUP
+TWORTN, ONESET
+OUTLOC, TWOOUT
+MHYP, -200
+
+
+
+
+VEESET, 0 /HERE TO LIMIT VELOCITY COMPONENTS
+ CLL
+ SPA /GET MAGNITUDE
+ CML
+ AND HM177 /LIMIT TO 177
+ SZL CLL
+ CIA
+ JMP I VEESET /AND EXIT
+
+HM177, 177
+
+ONEEXP, CLA CLL /HERE TO DISPLAY SHIP NUMBER ONE AS
+ TAD ONETHE /AN EXPLOSION
+ TAD INCONE /FIRST ROTATE IT BY A GOOD DOLLOP
+ DCA ONETHE
+ JMS I IXPDIS /THEN CALL THE EXPLOSION GENERATOR
+ ISZ ONEOUT /DONE WITH THE EXPLOSION?
+ JMP I NOWTWO /NO, NORMAL RETURN
+
+ IAC /YES, SET INTO PSEUDO HYPER SPACE
+ DCA ONEFLG
+ IAC /DISABLE RETURN FROM HYPER SPACE
+ DCA ONEFIN
+
+ TAD TWOFIN /IS NUMBER TWO STILL AROUND?
+ SNA CLA
+ JMP I NOWTWO /YES, RETURN
+ JMP I TIEUP /NO, TIE BALL GAME
+
+
+
+TWOEXP, CLA CLL /HERE TO DISPLAY SHIP NUMBER TWO
+ TAD TWOTHE /AS AN EXPLOSION. BASH IT AROUND
+ TAD INCTWO
+ DCA TWOTHE
+ JMS I IXPDIS /THEN DISPLAY IT
+ ISZ TWOOUT /DONE WITH EXPLOSION?
+ JMP I NOWPRO /NO, NORMAL RETURN
+
+ IAC /YES, SEND INTO PSEUDO HYPER SPACE
+ DCA TWOFLG
+ IAC /DISABLE NORMAL RETURN FROM HYPERSPACE
+ DCA TWOFIN
+ /CHECK NUMBER ONE
+ TAD ONEFIN
+ SZA CLA /STILL ALIVE AND WELL?
+ JMP I TIEUP /NO, TIE GAME
+ JMP I NOWPRO /YES, CONTINUE ON
+NOWTWO, TWODIS
+NOWPRO, PRODIS
+TIEUP, NOWIN
+IXPDIS, EXPDIS
+INCONE, 55
+INCTWO, 55
+
+
+
+/
+/ HERE TO DISPLAY THE FIGURE POINTED TO BY AUTO10 AS
+/ AN EXPLOSION. THIS WORKS THE SAME WAY AS THE NORMAL
+/ DISPLAY ROUTINE EXCEPT THAT THE COORDINATE INCREMENTS
+/ ARE INVERTED TURNING THE FIGURE INSIDE OUT FOR S
+/ A SORT OF CLOBBY EXPLOSION.
+/
+
+ *2400
+
+EXPDIS, 0 /HERE TO DISPLAY A FIGURE INSIDE OUT
+ TAD I AUTO10 /WITH THE POINTERS AND COUNTS ALREADY
+ DCA XTWODS /SET UP BY FILDIS OR TWODIS
+ TAD I AUTO10 /STICK NEXT TWO POINTS INTO LINE
+ DCA YTWODS
+
+ TAD XTWODS
+ CIA /CALCULATE INCREMENT THE WRONG WAY
+ TAD XONEDS
+ DCA DIXTEM /AND STORE
+ TAD YTWODS
+ CIA
+ TAD YONEDS
+ DCA DIYTEM /SAME FOR Y
+
+ TAD M4 /4 DOTS IN THE VECTOR"
+ DCA DISCNT /COULD HAVE CALLED THE OTHER
+ /VECTOR GENERATOR I SUPPOSE
+EXPLOP, TAD XONEDS
+ TAD DIXTEM /ADD X AND Y INCREMENTS TO THE RUNNING
+ DCA XONEDS /TOTALS AND DISPLAY THE RUNNING
+ TAD YONEDS /TOTALS NORMAL SIZE
+ TAD DIYTEM
+ DCA YONEDS
+
+ TAD XONEDS
+/ RTR /COULD MAKE TWICE AS BIG BY NOP-ING
+/ RAR /THE RAR'S BUT THE SCREEN IS SMALL ENOUGH
+ JMS I IVCLDX /AS IT IS
+ CLA
+ TAD YONEDS
+/ RTR
+/ RAR
+ JMS I IVCLDY
+/ DISD
+/ JMP .-1
+/ DIXY
+
+ CLA
+ ISZ DISCNT /DONE 4 DOTS?
+ JMP EXPLOP /NO
+
+ ISZ AUTO11 /DONE ALL VECTORS IN THE FILE?
+ SKP
+ JMP I EXPDIS /YES, EXIT
+
+ TAD XTWODS /NO SWAP TO NEXT PAIR OF POINTS
+ DCA XONEDS
+ TAD YTWODS
+ DCA YONEDS
+ JMP EXPDIS+1
+
+
+
+
+/
+/ VEELIM IS THE SCALING ROUTINE FOR VELOCITY COMPONENTS.
+/ THE COMPONENTS ARE SCALED TO REMAIN IN THE RANGE 140
+/ TO -140. THIS IS NECESSARY TO AVOID ASTRONOMICAL SPPED
+/ BUILDUP ON THE SMALL SCREEN. UNFORTUNATELY THE X AND Y
+/ COMPONENTS ARE SCALED SEPARATELY WHICH GIVES SLIGHT BUT
+/ NOTICABLE DISTORTIONS IN DIAGONAL FLIGHT PATHS. IN THE
+/ NORMAL HEAT OF THE BATTLE NO ONE WILL REALLY NOTICE.
+/
+
+
+VEELIM, 0 /ENTER TO SCALE VELOCITY HELD IN
+ DCA VEEHLD /AC
+ TAD VEEHLD
+ SMA /BRANCH FOR POSITIVE OR NEGATIV
+ JMP VEEPOS
+ TAD VEEMAX
+ SMA CLA /GREATER THAN MAXIMUM POSITIVE?
+ JMP VEECLR /NO
+ TAD VEEMIN /I MEAN MAXIMUM NEGATIVE - YES SET
+ JMP I VEELIM /TO MAX NEGATIV
+
+VEEPOS, TAD VEEMIN /GREATER THAN MAX?
+ SPA CLA
+ JMP VEECLR /NO
+ TAD VEEMAX /YES SET TO MAX
+ JMP I VEELIM
+
+VEECLR, TAD VEEHLD /IT WAS IN RANGE ALL ALONG
+ JMP I VEELIM
+
+VEEHLD, 0
+VEEMIN, -140
+VEEMAX, 140
+
+THEAJI, 0 /HERE TO ADJUST THE ANGLE TO A RANGE
+ SMA /0-550 OR 0-360 DEGREES. THIS IS
+ JMP .+3 /NECESSARY TO INSURE THAT PUSHDOWN OVERFLOW
+ TAD P550 /WILL NOT HAPPEN IN THE SINE AND COSINE
+ JMP .-3 /ROUTINES. THIS SIMPLY TAKES THE AC
+ TAD M550 /MODULO 360 AND EXITS
+ SMA
+ JMP .-2
+ TAD P550 /FOLLOW IT THROUGH AND SEE IF IT DOESN'T
+ JMP I THEAJI
+
+
+
+/
+/ ONE OF THESE ROUTINE IS ENTERED WHEN A WINNER IS DECLARED.
+/ THE ADDRESS OF THE VICTORY MESSAGE IS PLACED IN MESS AND
+/ THE GAMOVR FLAG SET TO CAUSE A BRANCH TO JOBLOP WHEN THE
+/ DISPLAY CYCLE IS COMPLETED. THE ROUTINE WILL THEN DISPLAY
+/ THE APPROPRIATE MESSAGE OVER THE REMAINING SHIPS IF
+/ ANY UNTIL THE KEYBOARD IS MOLESTED OR THE CLOCK RUNS OUT
+/ AND THE NEXT DISPLAY UPDATE CYCLE IS SET. AT ANY RATE THE
+/ PROGRAM WILL REACH HERE ONLY WHEN SOMEONE HAS BITTEN THE
+/ INTERGALACTIC DUST.
+/
+
+
+ONEWIN, 0 /THIS IS CALLED WHEN TWOFIN IS SET
+ TAD MES1 /AND ONE FIN IS NOT. SET ONE TO VICTOR
+ DCA MESS /AND SET GAMOVR FLAG
+ IAC
+ DCA GAMOVR
+ JMP I ONEWIN /THEN RETURN TO UPDATE CYCLE
+
+TWOWIN, 0 /THIS IS CALLED WHEN ONEFIN IS SET
+ TAD MES2 /AND TWO FIN IS NOT
+ DCA MESS /SET ALSO GAMOVR
+ IAC
+ DCA GAMOVR
+ JMP I TWOWIN
+
+NOWIN, TAD MES4 /GET HERE WHEN BOTH ONEFIN AND TWOFIN
+ DCA MESS /ARE SET .
+ IAC
+ DCA GAMOVR /NOBODY EVER REALLY WINDS
+ /UP THE WINNER IN THESE THINGS
+JOBLOP,
+/ DSB 1 /THIS IS ENTERED FROM FINISH WHEN
+ TAD MES0 /GAMOVR IS SET AND SERVES TO DISPLAY
+ JMS I MESOUT /THE VICTORY MESSAGE ON THE SCREEN
+ TAD MESS /USING THE CHARACTER GENERATOR SOMEWHAT
+ JMS I MESOUT /FURTHER ON UNTIL THE GAME IS RESTARTED
+ TAD MES5 /OR UNTIL THE INTERRUPT COUNT OVERFLOWS
+ JMS I MESOUT /AND THE UPDATE CYCLE IS RESTARTED
+ TAD MES3
+ JMS I MESOUT
+/FINITO, JMP JOBLOP
+FINITO, JMP .
+
+MES0, MESS0
+MES1, MESS1
+MES2, MESS2
+MES3, MESS3
+MES4, MESS4
+MES5, MESS5
+MESS, 0
+
+
+
+/
+/ THE FOLLOWING ARE THE SINE AND COSINE ROUTINES CUSTOMIZED
+/ FOR THIS PROGRAM FROM ANOTHER I WORKED ON. CALL EITHER
+/ SINE OR COSINE WITH ANGLE IN DEGREES IN AC. THE ARGUEMENT
+/ IS REDUCED THROUGH RECURSION UNTIL BETWEEN 0-89 DEGREES
+/ AND THEN A TABLE LOOKUP DONE TO OBTAIN THE VALUE. IT TAKES
+/ UP A FAIR AMOUNT OF SPACE BUT IT WORKS JUST FASTER
+/ THAN SHEEP. THE COSINE CALL JUST TRANSFORMS THE ARGUEMENT
+/ THROUGH SOME TRIGONOMETRIC GARBAGE AND CALLS THE SINE
+/ ROUTINE. NOTE THAT CALLING EITHER ROUTINE WITH TOO
+/ LARGE AN ARGUEMENT WILL CAUSE PUSHDOWN OVERFLOW AND THEN
+/ ALL HELL WILL BREAK LOOSE. THE ORIGINAL ROUTINE FROM WHICH
+/ THIS WAS STOLEN HAD FULL WORD PRECISION.
+/
+
+ *6400
+
+SINEIN, 0 /I REALLY CANT BRING MYSELF TO COMMENT
+ DCA SINARG /THIS. IT'S VERY STRAIGHFORWARD
+ TAD SINEIN
+ DCA I SINPSH
+ ISZ SINPSH
+ TAD SINARG
+ SZA
+ JMP SINNG2
+
+SINPOP, CLA CLL CMA
+ TAD SINPSH
+ DCA SINPSH
+ TAD I SINPSH
+ DCA SINEIN
+ TAD SINARG
+ JMP I SINEIN
+
+SINNG2, SMA
+ JMP SINPOS
+ CIA
+ JMS SINEIN
+
+SINNEG, CIA
+ DCA SINARG
+ JMP SINPOP
+
+SINPOS, TAD M264
+ SPA
+ JMP .+2
+ JMP SINNEG-1
+ TAD P132
+ SPA
+ JMP SINELK
+ SZA CLA
+ JMP .+3
+ TAD P37
+ JMP SINNEG+1
+
+ TAD SINARG
+ TAD M264
+ JMP SINNEG-1
+
+SINELK, TAD P132
+ TAD SINTAB
+ DCA SINEIN
+ TAD I SINEIN
+ DCA SINARG
+ JMP SINPOP
+
+
+
+
+SINARG, 0
+SINPSH, SINLST
+SINLST, 0
+ 0
+ 0
+ 0
+ 0
+ 0
+
+SINTAB, SINES-1
+
+COSINI, 0
+ CIA
+ TAD P132
+ JMS SINEIN
+ JMP I COSINI
+
+
+
+
+SINES, 00 /1
+ 01 /2
+ 01 /3
+ 02 /4
+ 02 /5
+ 03 /6
+ 03 /7
+ 04 /8
+ 05 /9
+ 05 /10
+ 06 /11
+ 06 /12
+ 07 /13
+ 07 /14
+ 10 /15
+ 10 /16
+ 11 /17
+ 11 /18
+ 12 /19
+ 12 /20
+ 13 /21
+ 13 /22
+ 14 /23
+ 15 /24
+ 15 /25
+ 16 /26
+ 16 /27
+ 17 /28
+ 17 /29
+ 20 /30
+ 20 /31
+ 20 /32
+ 21 /33
+ 21 /34
+ 22 /35
+ 22 /36
+ 23 /37
+ 23 /38
+ 24 /39
+ 24 /40
+ 25 /41
+ 25 /42
+ 25 /43
+ 26 /44
+ 26 /45
+ 27 /46
+ 27 /47
+ 27 /48
+ 30 /49
+ 30 /50
+ 30 /51
+ 31 /52
+ 31 /53
+ 31 /54
+ 32 /55
+ 32 /56
+ 32 /57
+ 33 /58
+ 33 /59
+ 33 /60
+ 33 /61
+ 34 /62
+ 34 /63
+ 34 /64
+ 35 /65
+ 35 /66
+ 35 /67
+ 35 /68
+ 35 /69
+ 36 /70
+ 36 /71
+ 36 /72
+ 36 /73
+ 36 /74
+ 36 /75
+ 37 /76
+ 37 /77
+ 37 /78
+ 37 /79
+ 37 /80
+ 37 /81
+ 37 /82
+ 37 /83
+ 37 /84
+ 37 /85
+ 37 /86
+ 37 /87
+ 37 /88
+ 37 /89
+
+
+
+
+MULTI, 0 /THIS IS STANDARD SINGLE PRECISION
+ CLL /MULTIPLY ROUTINE WHICH WAS ONCE
+ SPA /USED. I'VE LEFT IT IN SINCE
+ CMA CML IAC /THERE IS LOTS OF CORE LEFT OVER AND
+ DCA MULMP1 /MAYBLE SOMEDAY I'LL NEED IT TO PUT
+ DCA MULMP5 /IN A SUN OR SOMETHING. THIS IS THE
+ TAD I MULTI /STANDARD DEC SUBROUTINE WITH DIFFERENT
+ SNA /LABELS
+ JMP MULPSN+2
+ SPA
+ CMA CML IAC
+ DCA MULMP2
+ TAD MULTHR
+ DCA MULMP3
+
+MULMP4, TAD MULMP1
+ RAR
+ DCA MULMP1
+ TAD MULMP5
+ SZL
+ TAD MULMP2
+ CLL RAR
+ DCA MULMP5
+ ISZ MULMP3
+ JMP MULMP4
+ TAD MULMP1
+ RAR
+MULPSN, SZL
+ JMP MULCMP
+ DCA MULMP1
+ TAD MULMP5
+MULMPZ, ISZ MULTI
+ JMP I MULTI
+
+MULCMP, CMA CLL IAC
+ DCA MULMP1
+ TAD MULMP5
+ CMA
+ SZL
+ IAC
+ JMP MULMPZ
+
+MULTHR, 7764
+MULMP1, 0
+MULMP5, 0
+MULMP2, 0
+MULMP3, 0
+
+
+
+/
+/ SHIFTR DIVIDES THE AC BY TWO WHETHER POSITIVE OR NEGATIVE
+/ AND IS CALLED FROM VARIOUS PLACES. NOT ENTIRELY MYSTERIOUS
+/
+
+
+SHIFTR, 0
+ CLL
+ SPA
+ CML IAC
+ RAR
+ JMP I SHIFTR
+
+
+/
+/ POSCAL IS CALLED TO CALCULATE THE COORDINATE INCREMENTS
+/ NECESSARY TO PRODUCE THE SHIP FIGURES. RATHER THAN DOING
+/ A LOT OF EXPENSIVE MATH THIS DOES A QUICK PRODUCTION
+/ OF 1, 2, AND 3 TIMES THE SIN AND COSINE VALUES FOUND
+/ IN CALSIN AND CALCOS LEAVING THEM IN THE TABLE FOR
+/ ONESET AND TWOSET. IF THE SCOPE WERE ANY BETTER
+/ THIS PROBABLY WOULDN'T BE NEAR GOOD ENOUGH BUT....
+/
+
+POSCAL, 0
+ TAD CALSIN
+
+ DCA T10SIN
+ TAD T10SIN
+ CLL RAL
+ DCA T20SIN
+ TAD T10SIN
+ TAD T20SIN
+ DCA T30SIN
+
+ TAD CALCOS
+
+ DCA T10COS
+ TAD T10COS
+ CLL RAL
+ DCA T20COS
+ TAD T10COS
+ TAD T20COS
+ DCA T30COS
+ JMP I POSCAL
+
+/****************************************************************
+/ VC8-E ROUTINES
+
+
+/*****************************
+/ DIVISION BY 4 ROUTINE
+VDIV, 0
+ SMA / SKIP IF MINUS
+ JMP VPLUS
+VMINUS, CMA IAC / COMPLEMENT
+ RTR / DIVIDE BY FOUR
+ AND P1777 / DELETE UPPER TWO BITS
+ CMA IAC
+ JMP I VDIV / RETURN
+
+VPLUS, RTR / DIVIDE BY FOUR
+ AND P1777
+ JMP I VDIV
+
+/*****************************
+/ DIVISION BY 6 ROUTINE
+VDIV6, 0
+ SMA
+ JMP VPLUS6 /DO IN OTHER PLACE
+VMIN6, CIA /COMPLEMENT, NOW AC POSITIVE
+ JMS DIV6 /CALL DIVISION ROUTINE
+ CMA IAC /COMPLEMENT AGAIN
+ JMP I VDIV6
+
+VPLUS6, JMS DIV6 /CALL DIVISION ROUTINE
+ JMP I VDIV6 /RETURN TO CALLER
+
+/ EAE ROUTINE
+DIV6, 0
+ SWBA
+ MQL /LOAD MQ
+ MUY
+ 3
+ DVI
+ 20
+ SWP
+ JMP I DIV6
+
+/ SOFTWARE DIVISION ROUTINE (DOES NOT FIT!)
+IFNZRO 0 <
+DIV3, 0
+ DCA REST /INIT DIVISION REST
+ DCA RESLT /INIT RESULT
+
+ TAD (6000 /INITIAL DIVISOR * 2
+ DCA DIVI /STORE DYNAMIC DIVISOR
+
+ TAD (-12 /LOOP COUNTER, -10 (DEC)
+ DCA DCNT
+
+DLOOP, /DIVISION LOOP
+
+ TAD RESLT
+ RAL
+ DCA RESLT
+
+ TAD DIVI /CURRENT DIVISOR
+ RAR /ROTATE RIGHT
+ DCA DIVI
+
+TRY, TAD DIVI
+ CMA IAC /NEGATE
+ TAD REST /SUBSTRACT FROM REST
+ SPA
+ JMP BAD
+GOOD, /HIT!
+ CLL
+ DCA REST
+ ISZ RESLT
+
+BAD, /NO HIT, NO STORE, NO NOTHING
+ CLA
+
+ ISZ DCNT
+ JMP DLOOP /LOOP AGAIN
+
+ TAD RESLT
+ JMP I DIV3
+
+DCNT, 0
+RESLT, 0
+REST, 0
+DIVI, 0
+>
+
+/*****
+
+VCLDX, 0 / INTENSIFY LAST POINT AND LOAD NEW X VALUE
+ JMS VDIV6 / DIVIDE BY SIX
+ DISD / DISPLAY READY?
+ JMP .-1 / WAIT.
+ DIXY / INTENSIFY
+ DILX / LOAD NEW X VALUE
+ JMP I VCLDX / RETURN
+
+VCLDY, 0
+ JMS VDIV / DIVIDE BY FOUR
+ DILY / LOAD NEW Y VALUE
+ JMP I VCLDY
+
+P1777, 1777
+
+
+/****************************************************************
+
+
+ *7000
+
+/GENERAL PURPOSE SYMBOL GENERATOR
+/
+CHARS, 0 /ENTRY TO PLOT CHARACTER STRING
+ DCA ADDR /STORE STRING ADDRESS
+ TAD I ADDR /FETCH DOUBLE CHARACTER
+ RTR /SHIFT
+ RTR / FOR FIRST
+ RTR / CHARACTER
+ JMS CHAR /PLOT CHARACTER
+ SKP /NORMAL RETURN -- SKIP
+ JMP I CHARS /TERMINATION RETURN -- EXIT
+ TAD I ADDR /RECALL DOUBLE CHARACTER
+ ISZ ADDR /ADVANCE STRING ADDRESS
+ JMS CHAR /PLOT CHARACTER
+ JMP CHARS+2 /NORMAL RETURN -- REPEAT
+ JMP I CHARS /TERMINATION RETURN -- EXIT
+/
+CHAR, 0 /ENTRY TO PLOT SINGLE CHARACTER
+ AND K77 /MASK OUT UPPER BITS
+ CLL RAL /MULTIPLY CODE BY TWO
+ TAD TABLE /ADD TABLE BASE ADDRESS
+ DCA POINT /CONSTRUCT POINTER TO 24-BIT CODE
+ CMA /INITIALIZE COUNTER FOR
+ DCA COUNT2 / TWO PLOT WORDS
+ TAD I POINT /FETCH FIRST PLOT WORD
+ ISZ POINT /INCREMENT POINTER FOR NEXT ONE
+ SNA /SKIP IF NOT SPECIAL CHARACTER
+ JMP SPCHAR /ELSE GO PROCESS IT
+ DCA CURPLT /SAVE CURRENT PLOT BITS
+XPLOT, TAD KM6 /INITIALIZE 6-BIT
+ DCA COUNT6 / COUNTER
+ TAD YVALUE /RESET Y TEMPORARY
+ DCA YTEMP / VALUE FOR CHARACTER
+ TAD XVALUE /OUTPUT CURRENT
+ DILX /X-VALUE TO CRT
+ TAD XINCR /INCREMENT
+ DCA XVALUE / ABSCISSA
+YPLOT, TAD CURPLT /RECALL CURRENT PLOT BITS
+ CLL RAL /GET NEXT BIT
+ DCA CURPLT /SAVE REMAINING PLOT BITS
+ SNL /SKIP IF POINT TO PLOT
+ JMP CNTINU /ELSE JUMP AHEAD
+ TAD YTEMP /OUTPUT CURRENT
+ DILY /Y-VALUE TO CRT
+ DISD / READY TO DISPLAY THE POINT?
+ JMP .-1 / NO, WE'LL WAIT.
+ DIXY / SHOOT THE BEAM!
+
+ CLA CLL /CLEAR AC
+ TAD CURPLT /RECALL CURRENT PLOT BITS
+ SNA CLA /SKIP IF POINTS REMAINING
+ JMP WRDEND /ELSE WORD IS FINISHED
+CNTINU, TAD YTEMP /INCREMENT TEMPORARY
+ TAD YINCR / Y-VALUE FOR NEXT
+ DCA YTEMP / CHARACTER STEP
+ ISZ COUNT6 /SKIP IF 6 BITS PLOTTED
+ JMP YPLOT /ELSE PLOT NEXT ONE
+ JMP XPLOT /GO UPDATE X-VALUE
+WRDEND, ISZ COUNT2 /SKIP IF ANOTHER BIT WORD
+ JMP EXIT /ELSE EXIT
+ TAD I POINT /FETCH SECOND BIT WORD
+ SZA /SKIP IF NO PLOT POINTS
+ JMP XPLOT-1 /ELSE GO PLOT THEM
+EXIT, TAD XVALUE /INCREMENT ABSCISSA
+ TAD XINCR / FOR SPACE BETWEEN
+ DCA XVALUE / SYMBOLS
+ JMP I CHAR /EXIT FROM CHAR
+/
+SPCHAR, TAD I POINT /FETCH TRANSFER VECTOR
+ DCA POINT /STORE AS INDIRECT ADDRESS
+
+ JMP I POINT /GO TO APPROPRIATE ROUTINE
+SPACE, TAD XINCR /FETCH BASIC ABSCISSA INCREMENT
+ CLL RTL /MULTIPLY BY FOUR AND
+ JMP EXIT / GO CREATE SPACE
+CRLF, TAD INITX /"CARRIAGE RETURN" RESETS X
+ DCA XVALUE / TO ITS ORIGINAL VALUE
+LF, TAD YINCR /"LINE FEED"
+ CLL RTL / DECREMENTS THE
+ CLL CIA RAL / Y-VALUE BY
+ TAD YVALUE / EIGHT SCALE
+ DCA YVALUE / STEPS
+ JMP I CHAR /EXIT FROM CHAR
+RESET, TAD INITX /"RESET" RESETS
+ DCA XVALUE / X AND Y TO
+ TAD INITY / THEIR ORIGINAL
+ JMP RESET-2 / VALUES
+TERM, ISZ CHAR /TERMINATE CODE CAUSES
+ JMP I CHAR / EXIT TO P+2
+/
+INITX, 0 /INITIAL X-VALUE
+INITY, 327 /INITIAL Y-VALUE
+XVALUE, 0 /CURRENT X-VALUE
+YVALUE, 0 /CURRENT Y-VALUE
+XINCR, 6 /BASIC X INCREMENT VALUE
+YINCR, 10 /BASIC Y INCREMENT VALUE
+YTEMP, 0 /TEMPORARY Y-VALUE
+CURPLT, 0 /CURRENT PLOT BITS
+ADDR, 0 /CURRENT STRING ADDRESS
+COUNT6, 0 /6-BIT COUNTER
+COUNT2, 0 /2-WORD COUNTER
+KM6, -6 /CONSTANT FOR COUNT6
+K77, 77 /CHARACTER CODE MASK
+POINT, 0 /TABLE POINTER
+/
+
+
+/
+TABLE, .+1 /TABLE BASE ADDRESS
+ 0 /SPECIAL CHARACTER (00)
+ TERM /TERMINATION CODE
+ 7611 / A
+ 1176
+ 7745 / B
+ 4532
+ 3641 / C
+ 4122
+ 7741 / D
+ 4136
+ 7745 / E
+ 4541
+ 7705 / F
+ 501
+ 7741 / G
+ 5173
+ 7710 / H
+ 1077
+ 4177 / I
+ 4100
+ 2040 / J
+ 4037
+ 7714 / K
+ 2241
+ 7740 / L
+ 4040
+ 7702 / M
+ 277
+ 7706 / N
+ 3077
+ 7741 / O
+ 4177
+ 7705 / P
+ 502
+ 3641 / Q
+ 6176
+ 7715 / R
+ 2542
+ 2245 / S
+ 5122
+ 177 / T
+ 100
+ 3740 / U
+ 4037
+ 1720 / V
+ 4037
+ 7730 / W
+ 3077
+ 4136 / X
+ 3641
+ 374 / Y
+ 7403
+ 6151 / Z
+ 4543
+ 7741 / [
+ 0
+ 204 / \
+ 1020
+ 4177 / ]
+ 0
+ 436 / ^
+ 400
+ 0 /SPECIAL CHARACTER (37)
+ RESET /RESET
+ 0 /SPECIAL CHARACTER (40)
+ SPACE /SPACE
+ 5600 / !
+ 0
+ 303 / "
+ 0
+ 1477 / #
+ 7714
+ 2277 / MARKER
+ 2200
+ 2313 / %
+ 6462
+ 7777 / BLOCK
+ 7777
+ 300 / '
+ 0
+ 3641 / (
+ 0
+ 4136 / )
+ 0
+ 4040 / UNDERSCORE (52)
+ 4040
+ 1034 / +
+ 1000
+ 0 /SPECIAL CHARACTER (54)
+ LF /LINE FEED
+ 1010 / -
+ 1000
+ 4000 / .
+ 0
+ 2010 / /
+ 402
+ 3641 / 0
+ 4136
+ 4442 / 1
+ 7740
+ 4261 / 2
+ 5146
+ 2145 / 3
+ 5321
+ 1710 / 4
+ 1077
+ 4745 / 5
+ 4531
+ 7750 / 6
+ 5070
+ 6111 / 7
+ 503
+ 2255 / 8
+ 5522
+ 705 / 9
+ 577
+ 2400 / :
+ 0
+ 0 /SPECIAL CHARACTER (73)
+ CRLF /CARRIAGE RETURN; LINE FEED
+ 1024 / >
+ 4200
+ 1212 / =
+ 1200
+ 4224 / <
+ 1000
+ 255 / ?
+ 300
+
+
+
+/
+/ HERE FOLLOW THE PACKED ASCII TEXTS FOR THE VARIOUS
+/ VICTORY MESSAGES. PERSONS ADVENTEROUS TO FIND THIS MIGH CARE
+/ TO TOGGLE IN SOME CUTE LITTLE MESSAGES OF THEIR OWN.
+/
+
+MESS0, 3773
+MESS5, 7340
+ 4040
+ 4040
+ 4000
+
+MESS1, 1716
+ 0500
+
+MESS2, 2427
+ 1700
+
+MESS3, 2711
+ 1623
+ 4100
+
+MESS4, 1617
+ 0217
+ 0431
+ 0000
+
+ *7400
+
+DISBUF, 0
+
+/ THE DISPLAY BUFFERS BEGIN HERE AND EXTEND UP SOMEWHERE TO
+/ AROUND 7575 OR SO.
+/
+/
+/
+/
+/
+
+
+
+
+ $
+
+////////////////////////////
+/
+/ THIS IS THE END
+/
+///////////////////////////
+
+
+
+
+
+
--- /dev/null
+/ SPACE WAR
+/
+/ INTERPLANETARY DEATH AND DESTRUCTION ON YOUR
+/ LAB-8/E
+/
+/ HACHTI VARIANT FOR LAB-8/E
+/
+/ EVAN SUITS
+/
+/ THIS VERSION WORKS OFF EITHER THE BLUE RIBBON CONNECTOR OR THE
+/ SR. WHEN THE PROGRAM IS STARTED (AT 0200) OR RESTARTED THE
+/ SR WILL BE TESTED AND IF =0000 WILL BE USED FOR THE COMMAND
+/ INPUT. OTHERWISE, THE BLUE RIBBON CONNECTOR (AX08 * C0-C7 *
+/ XR OPTION ONLY) CONTINGENCY INPUTS WILL BE USED.
+/
+/ WHEN THE PROGRAM IS STARTED THE TWO SHIPS SHOULD
+/ APPEAR ON THE SCREEN WITH SHIP 'ONE' ON THE LEFT, SHIP
+/ 'TWO' ON THE RIGHT.
+/
+/ THE COMMAND WORD BIT ASSIGNMENTS ARE:
+/
+/ SR BIT: C: FUNCTION:
+/
+/ 0 0 SHIP ONE ROTATES LEFT
+/
+/ 1 1 SHIP ONE ROTATES RIGHT
+/
+/ 2 2 SHIP ONE ACCELERATES
+/
+/ 3 3 SHIP ONE FIRES
+/
+/
+/
+/ 8 4 SHIP TWO ROTATES LEFT
+/
+/ 9 5 SHIP TWO ROTATES RIGHT
+/
+/ 10 6 SHIP TWO ACCELERATES
+/
+/ 11 7 SHIP TWO FIRES
+/
+/
+/
+/ NOTE THAT TURNING RIGHT AND LEFT SIMULTANEOUSLY THROWS
+/ THE SHIP INTO HYPERSPACE. IN THE CURRENT VERSION THE ODDS
+/ ARE IN FAVOR OF YOUR MAKING IT BACK SAFELY. THE GAME IS OVER
+/ WHEN ONE OR BOTH OF THE SHIPS HAVE BEEN DESTROYED AND THE
+/ WINNER (IF ANY) IS IN NORMAL SPACE. WHEN THE WINNER
+/ HAS BEEN ANNOUNCED, HIT ANY TTY KEY TO RESTART.
+/
+
+
+/****************************************************************
+
+/***************************
+/ CLOCK OPERATIONS
+
+CLZE=6130 / CLEAR CLOCK ENABLE REGISTER PER AC
+CLSK=6131 / SKIP ON CLOCK FLAG
+CLOE=6132 / SET CLOCK ENABLE REGISTER PER AC
+CLAB=6133 / AC REGISTER TO CLOCK COUNTER REGISTER
+CLEN=6134 / CLOCK ENABLE REGISTER TO AC
+CLSA=6135 / STATUS TO AC
+CLBA=6136 / CLOCK BUFFER REGISTER TO AC
+CLCA=6137 / CLOCK COUNTER REGISTER TO AC
+
+/ BITS IN CLOCK ENABLE REGISTER
+CREXT=0100 / EXTERNAL SOURCE
+CR2=0200 / 10**2 per second
+CR3=0300 / 10**3 per second
+CR4=0400 / 10**4 per second
+CR5=0500 / 10**5 per second
+CR6=0600 / 10**6 per second
+
+COVSTAT=4000
+CMFREE=0000 / 4096 FIXED FREE RUN
+CMPROG=1000 / PROGRAMMED DELAY
+
+CADC=0040 / START ADC ON OVERFLOW
+CINH=0020 / INHIBIT CLOCK
+CION=0010 / INTERRUPT ENABLE
+
+CEV3=0004 / EVENT 3 ENABLED
+CEV2=0002 / EVENT 2 ENABLED
+CEV1=00001 / EVENT 1 ENABLED
+
+/ VC8-E OPCODES
+DIXY=6055 / INTENSIFY
+DILX=6053 / LOAD X
+DILY=6054 / LOAD Y
+DILE=6056 / LOAD ENABLES FROM A
+DISD=6052 / TEST FOR READY
+
+/****************************************************************
+/ SYMBOL DEFINITIONS FOR PAL8-PAL10
+
+XRIN=NOP / DIGITAL INPUT?
+XRCL=NOP
+
+/DSB=XXXX / SET BRIGHTNESS - MUST BE COMMENTED OUT!!!
+
+DXC=JMS I IVCLDX / X VALUE CONTROL?
+DYC=JMS I IVCLDY / Y VALUE CONTROL?
+
+DXL=0000 / X VALUE LOAD FLAG?
+DYL=0000 / Y VALUE LOAD FLAG?
+DIS=0000 / ANOTHER STRANGE FLAG
+
+/CRF=NOP / WHICH FLAG???
+/CCF=NOP / ??
+
+
+/****************************************************************
+/
+/ THIS PROGRAM RELIES ON THE PROGRAM INTERUPT FACILITY FOR
+/ REAL WORLD TIMING PURPOSES.
+/
+
+ *0
+
+ 0 /EFFECTIVE JMS 0 ON PROGRAM INTERUPT
+ JMP I 2 /EXIT IMMEDIATLY TO SERVICE ROUTINE
+ INTSER
+
+EMPTY, 0 /THESE LOCATIONS ARE RESERVED FOR
+ODT1, 0 /DEBUGGERS, ETC.
+ODT2, 0
+ODT3, 0
+
+/
+/ ALL THE AUTO INDEX REGISTERS ARE NAMED BUT NOT ALL OF
+/ THEM ARE USED. THE STATUS OF ANY GIVEN REGISTER CANNOT
+/ BE DETERMINED AT ANY TIME EXCEPT BY CAREFUL INSPECTION OF
+/ THE CODE.
+/
+
+ *10
+
+AUTO10, 0
+AUTO11, 0
+AUTO12, 0
+AUTO13, 0
+AUTO14, 0
+AUTO15, 0
+AUTO16, 0
+AUTO17, 0
+
+/
+/ THE FOLLOWING ARE THE DATA FILES FOR THE TWO SPACE SHIPS
+/ AS WELL AS CERTAIN OTHER PARAMETERS FOR CALCULATING POSITIONS
+/ AND SO ON. THE ORDER OF THE LOCATIONS MUST BE PRESERVED
+/ ALTHOUGH THE SIZE OF THE TABLES MAY BE VARIED
+/
+
+ *20
+
+ONEOUT, 0 /IF NON-ZERO CONTAINS REAMINING TIME OF EXPLOSION
+ONECNT, 0 /NUMBER OF POINTS IN FIGURE TO BE DISPLAYED
+ONEFLG, 0 /IN OR OUT OF NORMAL SPACE
+ONETHE, 0 /ANGLE OF ORIENTATION ON SCREEN
+ONEVEX, 0 /X COMPONENT OF VELOCITY
+ONEVEY, 0 /Y COMPONENT OF VELOCITY
+ONEPEX, 0 /X POSITION (12 BITS)
+ONEPEY, 0 /Y POSITION (12 BITS)
+ONESIN, 0 /SINE OF ANGLE
+ONECOS, 0 /COSINE OF ANGLE
+ONEFIN, 0 /SET WHEN EXPLOSION DIES OUT
+
+TWOOUT, 0 /SAME CONTENT AND ORDER
+TWOCNT, 0 /AS ABOVE
+TWOFLG, 0
+TWOTHE, 0
+TWOVEX, 0
+TWOVEY, 0
+TWOPEX, 0
+TWOPEY, 0
+TWOSIN, 0
+TWOCOS, 0
+TWOFIN, 0
+
+
+/
+/ THESE LOCATIONS ARE USED BY THE "VECTOR GENERATOR" IN
+/ DISPLAYING THE FIGURES. A FOUR DOT VECTOR WILL BE DRAWN
+/ FROM XONE,YONE TO XTWO,YTWO WITH STEPS OF SIZE DIXTEM,DIYTEM
+/
+
+XONEDS, 0
+YONEDS, 0
+XTWODS, 0
+YTWODS, 0
+DIXTEM, 0
+DIYTEM, 0
+DISCNT, 0
+
+
+/
+/ THE NEXT LOCATIONS ARE USED BY CALPOS TO DO A FAST
+/ MULTIPLY TO HELP CALCULATE THE DISPLAY FILES.
+/
+T10SIN, 0
+T20SIN, 0
+T30SIN, 0
+T10COS, 0
+T20COS, 0
+T30COS, 0
+
+CALSIN, 0
+CALCOS, 0
+
+/
+/ NOW COME THE VARIOUS ODDS AND ENDS ONE USUALLY FINDS ON
+/ PAGE ZERO
+/
+
+SINE, SINEIN
+COSINE, COSINI
+MULT, MULTI
+RSHIFT, SHIFTR
+VECTOR, DISPLY
+CALPOS, POSCAL
+INTWRD, 0
+INTCNT, 0
+/CLOCK, 0
+HYPER, HYPSET
+MESOUT, CHARS
+THEADJ, THEAJI
+VEESCL, VEELIM
+ISHFT, DISHFT
+RESET1, RESE1
+GAMOVR, 0
+ACCFLG, 0
+ACCPER, -30
+MEXP, -400
+
+PROX, 0
+PROY, 0
+PROLIF, -360
+BUFTMP, 0
+ONEFIL, DISBUF
+TWOFIL, DISBUF+40
+
+P5, 5
+P10, 10
+P17, 17
+P20, 20
+P37, 37
+P40, 40
+P100, 100
+P132, 132
+P200, 200
+P400, 400
+P550, 550
+P3777, 3777
+
+M4, -4
+M6, -6
+M10, -10
+M11, -11
+M264, -264
+M200, -200
+M400, -400
+M550, -550
+
+IVCLDX, VCLDX
+IVCLDY, VCLDY
+
+/
+/ THE PROGRAM MAY BE STARTED OR RESTARTED AT ANYTIME AT 0200.
+/ THE DATA FILE ON PAGE ZERO IS CLEARED, ALL FLAGS INITIALIZED,
+/ AND THE SR EXAMINED. IF THE SR=0 THE DISPLAY UPDATE ROUTINES
+/ ARE SET TO PICK UP THE STATUS WORD FROM THE SR. IF THE SR
+/ DOES NOT EQUAL ZERO, THE STATUS WORD IS READ FROM THE EIGHT
+/ CONTINGENCY INPUTS ON THE BLUE RIBBON CONNECTOR OF THE AX08
+/ (XR OPTION ONLY). JUMP IS THEN TO THE DISPLAY
+/ FILE UPDATE TO START OFF THE GAME.
+/
+
+CDI=6201
+
+ *200
+
+ CDI 0 / SET FIELD0
+
+START, CAF /START OR RESTART HERE ANY OLD TIME
+
+ DIXY /TO GET THE VC8-E STARTED ONCE
+ LAS /SR
+/TMP SNA CLA
+ TAD SWRD /USE THE SR
+ TAD XROPT /USE THE BLUE RIBBON CONNECTOR
+ DCA COLDST /AND LEAVE IN THE TRAP LOCATION
+
+RESTRT, CLA CMA
+ XRCL
+ CLA CLL
+
+ TAD P17 /FIRST CLEAR THE POSITION AND DATA
+ DCA AUTO10 /TABLES OF THE TWO SHIPS
+ TAD TABLEN
+ DCA AUTO11
+ DCA I AUTO10
+ ISZ AUTO11
+ JMP .-2
+
+ TAD STRT1 /SET THE STARTING POSITIONS OF THE
+ DCA ONEPEX /TWO SHIPS
+ TAD STRT2
+ DCA TWOPEX
+ TAD P37 /SET TRIG FUNCTIONS JUST IN CASE
+ DCA ONECOS
+ TAD P37
+ DCA TWOCOS /ZERO DEGREES IS POINTING STRAIGHT UP
+ TAD ACCPER /SET COUNT FOR VELOCITY INCREASE
+ DCA ACCFLG
+ DCA ONEFIN /CLEAR ALL GAME END FLAGS
+ DCA TWOFIN
+ DCA GAMOVR
+ JMS I BUFSET /RESET ALL PROJECTILE DISPLAY BUFFERS
+
+
+ TCF /CLEAR OTHER REMAINING LIKELY FLAGS
+ PCF
+/ RRB
+
+ 6405 / CLEAR INTERRUPT ENABLE OF KERMIT'S SER PORT :-(
+
+ CLA CMA / ALL ONES
+ CLZE / CLEAR CLOCK CONFIG REGISTER
+ CLA
+ TAD CDELY / LOAD NEG DELAY
+ CLAB / LOAD TO CLOCK BUFFER
+ CLA
+ TAD CCNF / LOAD CLOCK CONFIG
+ CLOE / SET CONFIG BITS
+
+ CLA CLL
+ JMP COLDST /AND GO TO IT
+
+CCNF, CR4+CMPROG+CION+COVSTAT / CLOCK CONFIGURATION
+CDELY, -310 / COUNTER PRESET (200)
+
+/
+/ UPDATE IS REACHED WHENEVER THE PROGRAM IS STARTED OR THE
+/ CLOCK COUNT OVERFLOWS INDICATING TIME TO RECALCULATE THE
+/ THE DISPLAY FILES AND REFRESH THE DISPLAY. THE INTERUPT
+/ COUNT IS RESTORED, THE STATUS WORD IS PICKED UP FROM EITHER
+/ THE SR OR BRC, AND THE RECALCULATION PROCESS BEGUN.
+/
+
+UPDATE, CLA CLL /HERE ON CLOCK COUNT OVERFLOW.
+ /START NEXT SWEEP
+COLDST, 0 /TRAP TO READ SR OR BRC
+ LAS /HERE FOR SR
+ DCA INTWRD /STORE TEMPORARILY
+ TAD INTWRD /MASK OUT LEFTMOST 4 BITS
+ RTR /FOR NUMBER ONE
+ RTR
+ AND LFTHAF
+ DCA INTTEM /AND STORE
+ TAD INTWRD /MASK OUT RIGHTMOST BITS FOR NUMBER TWO
+ AND RYTHAF
+ TAD INTTEM /ADD TOGETHER
+ JMP .+3 /AND CONTINUE
+
+CODST, XRIN /HERE FOR BRC - PICK UP AND CLEAR
+ XRCL
+ DCA INTWRD /CONTINUE
+ TAD M550 /RESTORE INTERUPT COUNT BEFORE NEXT
+ DCA INTCNT /UPDATE
+ ION /GET READY FOR THE NEXT CYCLE
+ TAD ACCFLG /ALLOW VELOCITY INCREASE THIS TIME?
+ IAC /ONLY WHEN ACCFLG=0
+ SMA SZA
+ TAD ACCPER /IF ZERO, RESET COUNT
+ DCA ACCFLG
+
+ JMP I .+1 /NOW GET DOWN TO WORK.
+ ONEUP
+
+BUFSET, SETBUF
+TABLEN, AUTO17-CALCOS
+INTTEM, 0
+LFTHAF, 0360
+RYTHAF, 0017
+STRT1, 1000
+STRT2, -1000
+SWRD, 2000-CODST
+XROPT, JMP CODST
+
+
+
+/
+/ THIS IS THE INTERUPT SERVICE ROUTINE. MOST OF THE
+/ INTERUPTS WILL BE FROM THE CRYSTAL CLOCK WHICH WILL BE
+/ COUNTED AND UNLESS THE COUNT OVERFLOWS THE INTERUPT IS
+/ DISMISSED IMMEDIATLY. IF THE COUNT OVER FLOWS, JMP IS TO
+/ UPDATE WITH IOF.
+/
+/ SPECIAL CASE IS KEYBOARD INTERUPT WHEN THE GAMOVR FLAG IS
+/ SET IN WHICH CASE THE GAME IS RESTARTED.
+/
+/ UNEXPECTED INTERUPTS ARE COUNTED AND AFTER ENOUGH OF THEM
+/ HAPPEN THE PROGRAM HALTS. IF THIS HAPPENS RELOAD OR FIND THE
+/ STRANGE FLAG
+/
+
+INTSER, DCA INTACC /HERE RIGHT AFTER INTERUPT - STORE
+ RAR /AC AND LINK
+ DCA INTLNK /FOR POSSIBLE CONTINUATION
+
+ CLSK /WAS IT THE CRYSTAL CLOCK?
+ JMP INTBUS /NO TRY SOMETHING ELSE
+
+ CLA IAC RTR /LOAD 4000
+ CLSA /GET CLOCKSTATUS AND RESET FLAG
+ CLA CLL
+ JMP UPDATE /YES, GO TO IT
+
+INTBUS, /HERE ON NON-CLOCK INTERUPT
+
+ KSF
+ JMP NOKEY /NOT THE KEYBOARD, THAT'S BAD!
+
+KBDIN, KCC /CLEAR KEYBOARD FLAG
+
+ KRB / RESET FLAG, CLEAR AC, READ DATA
+ AND KPAR / MASK OUT PARITY
+ TAD NCTRLC / ADD -3 (CTRL-C)
+ SNA CLA
+ JMP I KBOOT / REBOOT!
+
+ TAD GAMOVR /IS THE GAMEOVER
+ SZA CLA
+ JMP RESTRT /YES, RESTART
+
+ KRB
+ AND KPAR
+ TAD NCTRLD
+ SNA CLA
+ JMP RESTRT
+
+ JMP INTRET
+
+NOKEY, / STILL NOT FOUND INTERRUPT SOURCE :-(
+ TSF / SKIP IF PRINTER FLAG SET
+ JMP BADDIE / NOT THE PRINTER, NO NEW IDEAS - BAD
+ TCF / CLEAR THAT FLAG
+ JMP INTRET / AND GO HOME
+
+KBOOT, 7600
+KPAR, 177 / ANTI-PARITY MASK
+NCTRLC, 7775 / -3 (CTRL-C)
+NCTRLD, 7774 / -3 (CTRL-D)
+
+
+BADDIE, ISZ INTGLH /COUNT ONE BADDIE
+ SKP
+ HLT /HALT IF TOO MANY BADDIES
+
+INTRET, CLA CLL /HERE TO DISMISS THE INTERUPT
+
+ PCF
+/ RRB
+
+ TAD INTLNK
+ RAL
+ TAD INTACC
+ ION
+ JMP I 0
+
+INTACC, 0
+INTLNK, 0
+INTGLH, 0
+
+
+
+/
+/ NOW BEGINS THE GREAT UPDATE PROCEEDURE, FIRST FOR SHIP
+/ NUMBER ONE (THE DELTA SHAPED SHIP WHICH APPEARS ON
+/ THE LEFT AT THE START OF THE GAME). IF ALIVE THE STATUS
+/ WORD (INTWRD) IS TESTED FOR REQUESTS FOR LEFT TURN,
+/ RIGHT TURN, THRUST ON, AND LAUNCH PROJECTILE. THESE ACTIONS
+/ MAY OR MAY NOT BE ACTED UPON DEPENDING ON COUNTS AND FLAGS.
+/ WHEN THIS IS COMPLETE THE SAME OPERATION IS PERFORMED FOR
+/ NUMBER TWO.
+/
+
+ *400
+
+ONEUP, TAD ONEFLG /FIRST SEE IF IT'S IN NORMAL SPACE
+ SNA
+ JMP ONEOK /YES IT IS
+ IAC /NO, BUT IS IT JUST COMING OUT?
+ SNA
+ TAD ONEFIN /YES, THROW BACK IN IF ALREADY DESTROYED
+ DCA ONEFLG /OTHERWISE JUST COUNT ONE
+ JMP I ITWOUP /AND GO TO FIX UP NUMBER TWO
+
+ONEOK, TAD ONEOUT /IN NORMAL SPACE - IS IT EXPLODING?
+ SZA CLA
+ JMP ONEFIG /IF YES, ALLOW NO CONTROLS
+ TAD TWOFIN /HAS THE ENEMY BEEN VANQUISHED?
+ SZA CLA
+ JMS I ONEWN /YES, SIGNAL VICTORY
+ TAD INTWRD /NOW BEGIN TEST OF REQUEST
+ AND OP300 /LEFT AND RIGHT TURN TOGETHER MEAN HYPERSPACE!
+ TAD OM300 /TEST BITS 4 AND 5
+ SZA CLA
+ JMP ONELEF /NOPE, CONTINUE
+ CMA /YES, CALL HYPER WITH AC=-1 FOR NUMBER ONE
+ JMP I HYPER
+ONELEF, TAD INTWRD /REQUEST FOR LEFT TURN?
+ AND P200 /TEST BIT 4
+ SNA CLA
+ JMP ONERYT /NO
+ CLA CLL CMA /YES DECREMENT ANGLE
+ JMP ONEFIG
+
+ONERYT, TAD INTWRD /HOW ABOUT RIGHT TURN
+ AND P100 /TEST BIT 5
+ SZA CLA
+ IAC /YES, INCREMENT ANGLE
+
+ONEFIG, TAD ONETHE /PICK UP AND ADJUST ANGLE (MAYBE)
+ JMS I THEADJ /BRING BACK WITHIN LIMITS OF TRIG FUNCTIONS
+ DCA ONETHE /AND STORE
+ TAD ONETHE /FIND THEM TRIG FUNCTIONS
+ JMS I SINE /AND STORE ONCE AND FOR ALL
+ DCA ONESIN /IN THE APPROPRIATE PLACES
+ TAD ONETHE
+ JMS I COSINE
+ DCA ONECOS
+ TAD ONEOUT /DO NOT ALLOW THRUST IF EXPLODING
+ SZA CLA
+ JMP ONEVEL
+
+
+
+
+ONEMOV, TAD ACCFLG /ALLOW ANY VELOCITY INCREASE THIS CYCLE?
+ SZA CLA
+ JMP ONEVEL /NOPE
+ TAD INTWRD /YES, ANY REQUESTED?
+ AND P40 /TEST BIT 6
+ SNA CLA
+ JMP ONEVEL /NONE REQUESTED
+ TAD ONECOS /YES, ADD IN VELOCITY INCREMENT DEPENDING
+ TAD ONEVEY /ON ORIENTATION
+ JMS I VEESCL /BUT DO NOT ALLOW TO EXCEED MAXIMUM
+ DCA ONEVEY /AND STORE
+ TAD ONESIN /DO THE SAME FOR THE OTHER (X) COMPONENT
+ TAD ONEVEX
+ JMS I VEESCL
+ DCA ONEVEX
+
+
+
+ONEVEL, TAD ONEVEX /NOW UPDATE THE POSITION WITH THE
+ JMS I ISHFT /VELOCITY COMPONENTS DIVIDED BY 4
+ JMS I ISHFT /THIS MAINTAINS MAXIMUM RESOLUTION
+ TAD ONEPEX
+ DCA ONEPEX /IGNORE ANY OVERFLOW
+ TAD ONEVEY /DO THE SAME FOR Y COORDINATE
+ JMS I ISHFT /AND VELOCITY COMPONENT
+ JMS I ISHFT
+ TAD ONEPEY
+ DCA ONEPEY
+ TAD ONEOUT /DO NOT ALLOW PROJECTILE LAUNCH IF
+ SZA CLA /EXPLODING
+ JMP I ITWOUP
+
+
+
+
+ONELNC, TAD LNC1FG /OTHERWISE, SEE IF RELOAD IS FINISHED
+ SNA CLA
+ JMP .+3
+ ISZ LNC1FG /NO, CONTINUE RELOADING
+ JMP I ITWOUP /AND EXIT
+ TAD INTWRD /YES, READY TO LAUNCH, TRIGGER BEEN PULLED?
+ AND P20 /TEST BIT7
+ SNA CLA
+ JMP I ITWOUP /NO, WAIT FOR A BETTER SHOT
+ /.....I GUESS.....
+ TAD PROLIF /YES, SET CYCLE COUNT FOR THIS LAUNCH
+ DCA I AUTO16 /AUTO16 ALWAYS POINTS AT THE NEXT SLOT IN THE FILE
+ TAD ONEVEX /ADD SHIPS VELOCITY (SCALED OF COURSE)
+ JMS I ISHFT /TO ORIENTATION TO EXTABLISH X VELOCITY
+ JMS I RSHIFT /COMPONENT OF PROJECTILE
+ TAD ONESIN
+ JMS I RSHIFT /AND STICK IT IN THE FILE
+ DCA I AUTO16
+ TAD ONESIN /MOVE THE LAUNCH POINT OUTSIDE THE
+ CLL RTL /SHIP OF ORIGIN
+ TAD ONEPEX
+ DCA I AUTO16 /AND STORE X POSITION
+ TAD ONEVEY /NOW DO THE SAME FOR THE Y VELOCITY AND
+ JMS I ISHFT /POSITION
+ JMS I RSHIFT
+ TAD ONECOS
+ JMS I RSHIFT
+ DCA I AUTO16
+ TAD ONECOS
+ CLL RTL
+ TAD ONEPEY
+ DCA I AUTO16
+ TAD M200 /START RELOAD CYCLE
+ DCA LNC1FG
+ JMS I RESET1 /RESET AUTO16 TO NEXT HOLE
+
+ JMP I .+1 /NOW TO FIX IT UP WITH NUMBER TWO
+ITWOUP, TWOUP
+
+LNC1FG, 0 /PROJECTILE LAUNCH ENABLE
+
+OP300, 300 /HYPERSPACE REQUEST CODE BITS 4 AND 5
+OM300, -300
+ONEWN, ONEWIN /POINTER TO VICTORY MESSAGE
+
+
+
+/
+/ HERE BEGINS THE UPDATE PROCEEDURE FOR SHIP NUMBER TWO.
+/ OPERATION IS THE SAME AS FOR NUMBER ONE ABOVE.
+/
+
+ *600
+
+TWOUP, TAD TWOFLG /FIRST SEE IF IT'S IN NORMAL SPACE
+ SNA
+ JMP TWOOK /YES, CONTINUE
+ IAC /NO, BUMP COUNT AND TEST FOR REENTRY
+ SNA
+ TAD TWOFIN /IF RE-ENTERING THROW BACK OUT IF FINISHED
+ DCA TWOFLG /AND CONTINUE
+ JMP I IONEST
+
+TWOOK, TAD TWOOUT /HERE WHEN READY TO UPDATE IN NORMAL SPACE
+ SZA CLA /IS IT EXPLODING?
+ JMP TWOFIG /YES DO NOT ALLOW HYPERSPACE
+ TAD ONEFIN /DID WE JUST WIN?
+ SZA CLA
+ JMS I TWOWN /YES ENABLE END OF GAME MESSAGE
+ TAD INTWRD /TEST FOR HYPERSPACE REQUEST
+ AND OP14
+ TAD OM14 /BITS 8 AND 9 MUST BE SET
+ SNA CLA
+ JMP I HYPER /8 AND 9 SET. ENTER HYPER ROUTINE WITH AC=0
+ /FOR SHIP NUMBER 2
+TWOLEF, TAD INTWRD /TEST FOR LEFT TURN - BIT 8
+ AND P10
+ SNA CLA
+ JMP TWORYT /NOT SET
+ CLA CLL CMA /SET, DECREMENT TWOTHE BY 1 DEGREE
+ JMP TWOFIG /SKIP TEST FOR RIGHT TURN
+
+TWORYT, CLA CLL IAC RTL /TEST FOR RIGHT TURN - BIT 9
+ AND INTWRD
+ SZA CLA
+ IAC /IF SET INCREMENT TWOTHE BY 1 DEGREE
+
+TWOFIG, TAD TWOTHE /UPDTAE TWOTHE
+ JMS I THEADJ /BRING TO WITHIN LIMITS OF SINE,COSINE
+ DCA TWOTHE /AND STORE
+ TAD TWOTHE
+ JMS I SINE /CALCULATE SINE AND COSINE FUNCTIONS
+ DCA TWOSIN /AND STORE IN DATA TABLE
+ TAD TWOTHE
+ JMS I COSINE
+ DCA TWOCOS
+ TAD TWOOUT /DO NOT ALLOW VELOCITY CHANGE IF EXPLODING
+ SZA CLA
+ JMP TWOVEL
+
+
+
+
+TWOMOV, TAD ACCFLG /NOW FOR ACCELERATION. TEST TO SEE IF ALLOWED
+ SZA CLA /DURING THIS UPDATE CYCLE
+ JMP TWOVEL /NOPE
+ CLL IAC RAL /YES, TEST FOR BIT 2 SET
+ AND INTWRD
+ SNA CLA
+ JMP TWOVEL /NOT SET
+
+ TAD TWOSIN /UPDATE X VELOCITY COMPONENT BY SINE OF
+ TAD TWOVEX /ANGLE OF ORIENTATION
+ JMS I VEESCL /AND SCALE TO NOT EXCEED MAX
+ DCA TWOVEX /UPDATE Y COMPONENT WITH COSINE
+
+ TAD TWOCOS
+ TAD TWOVEY
+ JMS I VEESCL
+ DCA TWOVEY
+
+
+
+TWOVEL, TAD TWOVEX /NOW UPDATE THE POSITION WITH THE VELOCITY
+ JMS I ISHFT /COMPONENTS/16
+ JMS I ISHFT
+ TAD TWOPEX
+ DCA TWOPEX
+ TAD TWOVEY
+ JMS I ISHFT
+ JMS I ISHFT
+ TAD TWOPEY
+ DCA TWOPEY
+ TAD TWOOUT
+ SZA CLA
+ JMP I IONEST
+
+
+
+
+TWOLNC, TAD LNC2FG /NOW CHECK FOR PROJECTILE LAUNCH. FIRST
+ SNA CLA /TEST TO SEE IF RELOAD COMPLETE
+ JMP .+3
+ ISZ LNC2FG /NO, COUNT ONE CYCLE AND EXIT
+ JMP I IONEST
+ IAC /YES, TEST TRIGGER BIT 11
+ AND INTWRD
+ SNA CLA
+ JMP I IONEST /NOT SET, HELL WITH IT
+
+ TAD PROLIF /OK, SET PROJECTILE LIFE
+ DCA I AUTO16 /AUTO16 IS ALWAYS POINTING AT THE NEXT SLOT
+ TAD TWOVEX /ADD SHIPS VELOCITY
+ JMS I ISHFT /(ADJUSTED)
+ JMS I RSHIFT
+ TAD TWOSIN /TO THAT OF PROJECTILE - AGAIN X COMPONENT
+ JMS I RSHIFT /FROM SINE OF ANGLE OF ORIENTATION
+ DCA I AUTO16
+ TAD TWOSIN /SET INITIAL POSITION TO BE JUST AHEAD
+ CLL RTL /OF THE SHIP
+ TAD TWOPEX /X COMPONENT
+ DCA I AUTO16
+ TAD TWOVEY /NOW THE Y COMPONENTS FROM Y VELOCITY
+ JMS I ISHFT /Y POSITION AND COSINE
+ JMS I RSHIFT
+ TAD TWOCOS
+ JMS I RSHIFT
+ DCA I AUTO16
+ TAD TWOCOS
+ CLL RTL
+ TAD TWOPEY
+ DCA I AUTO16
+ TAD M200
+ DCA LNC2FG /200 CYCLES OF RELOAD
+ JMS I RESET1 /DRINK LEADEN DEATH, NUMBER ONE!
+
+ JMP I .+1 /FINAL EXIT TO DISPLAY FILE CALCULATIONS
+IONEST, ONESET
+
+LNC2FG, 0 /RELOAD COUNT
+
+OP14, 14 /HYPERSPACE CODE
+OM14, -14
+TWOWN, TWOWIN
+
+
+
+/
+/ HERE BEGINS THE DISPLAY CALCULATIONS FOR THE TWO SHIPS. AT
+/ THIS POINT ONLY THE POSITION AND ORIENTATION OF EACH VESSEL
+/ IS ONF INTEREST SINCE THE VELOCITY AND ALL THAT HAVE ALREADY
+/ BEEN TAKEN CARE OF. FOR THE BOTH SHIPS THE DISPLAY FILES ARE
+/ CALCULATED AS A SERIES OF PAIRS OF X,Y COORDINATES. BETWEEN
+/ EACH PAIR OF POINTS A FOUR POINT VECTOR WILL BE DRAWN. THE
+/ ACTUAL COORDINATES ARE CALCULATED AS DISPLACEMENTS
+/ FROM THE CENTRAL PSOTION OF THE SHIP, TAKING INTO ACCOUNT THE
+/ ANGLE OF ORIENTATION. THE FORMULAS FOLLOWED ARE:
+/
+/ X(POINT)=X(BASE)+X(REL)*COS[THE]+Y(REL)*SINE[THE]
+/
+/ Y(POINT)=Y(BASE)+Y(REL)*COS[THE]-X(REL)*SINE[THE]
+/
+/ WHERE SINE[THE] AND COS[THE] ARE THE FUNCTIONS OF THE
+/ ANGLE OF ORIENTATION, X(BASE) AND Y(BASE) ARE THE
+/ COORDINATES OF THE SHIPS POSITION AND X(REL) AND Y(REL)
+/ CORRESPOND TO DISPLACEMENT PAIRS DEPENDING ON THE SHAPE
+/ OF THE FIGURE. ALL X AND Y RELS LIE WITHIN THE RANGE 0-3 AND
+/ THERE FORE ALL NECESSARY DISPLACEMENTS FROM BASE COORDINATES
+/ MAY BE CALCULATEDFROM DIFFERENT COMBINATIONS OF T10SIN, T20COS
+/ ETC. THESE VALUES ARE CALCULATED BY A CALL TO POSCAL WITH THE SINE
+/ AND COSINE OF THE ANGLE OF INTEREST IN CALSIN AND CALCOS.
+/
+/ FOLLOWING THIS METHOD ANY FIGURE DESCRIBABLE WITH A 7 BY 7
+/ MATRIX OF POINTS MAY BE QUICKLY CALCULATED.
+/
+/ BEGINNING AT ONESET DIFFERENT DISPLACEMENT PAIRS ARE CALCULATED
+/ AND DEPOSITIED THROUGH AUTO10 TO FORM THE DISPLAY FILE FOR SHIP NUMBER ONE.
+/
+
+
+ *1000
+
+ONESET, CLA CLL /BEGIN DISPLAY FILE FOR NUMBER ONE
+ TAD ONEFLG /DONT BOTHER IF NOT IN NORMAL SPACE
+ SZA CLA
+ JMP I ITWOST
+ TAD ONESIN /SET UP FOR MATRIX COMPONENT CALCULATIONS
+ DCA CALSIN
+ TAD ONECOS
+ DCA CALCOS
+ JMS I CALPOS /CALL THE CALCULATOR
+
+/
+/ CONSIDER THE 7 BY 7 MATRIX OF DISPLACEMENT POINTS WITH THE
+/ CENTER AT 0,0 CORRESPONDING TO THE SHIPS POSITION. A SERIES
+/ OF POINTS IS NOW DESCRIBED AROUND THIS CENTER USING THE
+/ MULTIPLES OF THE TRIG FUNCTIONS JUST CALCULATED
+/ SO THAT ANY POINT ON THE OUTLINE IS DESCRIBABLE AS X,Y
+/ DISPLACED BY X,Y OF THE SHIP ITSELF
+/
+
+ TAD ONEFIL /SET UP AUTO10 AS THE DISPLAY FILE
+ DCA AUTO10 /POINTER
+ TAD ONEPEX /THE FIRST POINT OF THE OUTLINE IS
+ TAD T30SIN
+ DCA I AUTO10 / 0,3 OR TOP CENTER
+ TAD ONEPEY
+ TAD T30COS
+ DCA I AUTO10
+
+ TAD T10COS
+ CIA /THE SECOND IS
+ TAD ONEPEX
+ DCA I AUTO10 / -1,0
+ TAD T10SIN /OR JUST LEFT OF DEAD CENTER
+ TAD ONEPEY /AND SO ON
+ DCA I AUTO10
+
+ TAD T30SIN
+ TAD T30COS /THE THIRD POINT IS
+ CIA
+ TAD ONEPEX / -3,-3
+ DCA I AUTO10
+ TAD T30COS /OR BOTTOM LEFT HAND CORNER
+ CIA
+ TAD T30SIN
+ TAD ONEPEY
+ DCA I AUTO10
+
+
+
+
+ TAD T10SIN
+ CIA /FOURTH POINT
+ TAD ONEPEX
+ DCA I AUTO10 / 0,-1
+ TAD T10COS
+ CIA /OR JUST BELOW CENTER
+ TAD ONEPEY
+ DCA I AUTO10
+
+FLAM1, TAD INTWRD /TEST FOR POWER ON. IF ON, DRAW THE
+ AND P40 /FLAME WITH AN EXTRA POINT SOME
+ SNA CLA /DISTANCE DIRECTLY BELOW THE SHIP
+ JMP ONECON /POWER NOT ON - CONTINUE
+ TAD ONEOUT /DO NOT ALLOW IF EXPLODING
+ SZA CLA
+ JMP ONECON
+
+ TAD ONFG1 /USE ONFG1 TO TURN THE FLAME ON AND
+ SNA /OFF TO MAKE IT FLICKER. DISPLAY THE
+ CLA CLL CMA RAL /FLAME ONE TIME OUT OF THREE
+ DCA ONFG1
+
+ ISZ ONFG1
+ JMP ONECON /ONE OUT OF THREE TIMES THIS WILL SKIP
+
+ TAD ONFG2 /VARY ALSO THE LENGHT OF THE FLAME
+ CMA /WITH LONG SHORT LONG SHORT
+ DCA ONFG2
+
+ TAD ONFG2 /TIP OF FLAME AT EITHER
+ SNA CLA
+ TAD T10SIN / 0,-4 OR
+ TAD T30SIN / 0,-3
+ CIA
+ TAD ONEPEX
+ DCA I AUTO10
+ TAD ONFG2
+ SNA CLA
+ TAD T10COS
+ TAD T30COS
+ CIA
+ TAD ONEPEY
+ DCA I AUTO10
+
+ TAD T10SIN
+ CIA
+ TAD ONEPEX /RETURN DISPLAY TO 0,-1
+ DCA I AUTO10
+ TAD T10COS
+ CIA
+ TAD ONEPEY
+ DCA I AUTO10
+ CLA CLL CMA RAL /ADD -2 TO POINT COUNT
+
+
+
+
+ONECON, TAD M6 /SET POINT COUNT TO -6 OR -8
+ DCA ONECNT
+
+ TAD T30SIN /CONTINUE WITH DISPLAY FILE - THIS POINT
+ CIA
+ TAD T30COS / AT 3,-3
+ TAD ONEPEX /
+ DCA I AUTO10 /OR LOWER RIGHT HAND CORNER
+ TAD T30SIN
+ TAD T30COS
+ CIA
+ TAD ONEPEY
+ DCA I AUTO10
+
+ TAD T10COS /NEXT
+ TAD ONEPEX /
+ DCA I AUTO10 / 1,0
+ TAD T10SIN /
+ CIA / OR JUST RIGHT OF CENTER
+ TAD ONEPEY
+ DCA I AUTO10
+
+ TAD T30SIN /FINALLY BACK TO
+ TAD ONEPEX /
+ DCA I AUTO10 / 0,3
+ TAD T30COS /
+ TAD ONEPEY / TOP CENTE
+ DCA I AUTO10
+
+ JMP I ITWOST /NOW FOR NUMBER TWO
+ITWOST, TWOSET
+
+ONFG1, 0 /USED TO COUNT FLICKERS
+ONFG2, 0 /SHORT OR LONG FLAG
+
+
+
+/
+/ HERE BEGINS THE DISPLAY FILE GENERATOR FOR SHIP TWO.
+/ IT WORKS JUST LIKE THE ONE FOR NUMBER ONE BUT WITH
+/ DIFFERENT DISPLACEMENT PAIRS AND TWO EXTRA POINTS
+/
+
+ *1200
+
+TWOSET, CLA CLL /DONT BOTHER IF NOT IN NORMAL SPACE
+ TAD TWOFLG
+ SZA CLA
+ JMP I IFILDS
+ TAD TWOSIN /SET UP TO HAVE DISPLACEMENT INCREMENTS
+ DCA CALSIN /CALCULATED
+ TAD TWOCOS
+ DCA CALCOS
+ JMS I CALPOS
+
+ TAD TWOFIL /SET AUTO10 TO POINT TO SECOND DISPLAY
+ DCA AUTO10 /FILE
+ TAD T30SIN /FIRST POINT AT
+ TAD TWOPEX /
+ DCA I AUTO10 / 0,3
+ TAD T30COS /
+ TAD TWOPEY / OR TOP CENTER
+ DCA I AUTO10
+
+ TAD T20COS
+ CIA
+ TAD T20SIN
+ TAD TWOPEX
+ DCA I AUTO10
+ TAD T20SIN
+ TAD T20COS /SECOND POINT
+ TAD TWOPEY / -2,2
+ DCA I AUTO10
+
+ TAD T20COS /THIRD POINT
+ CIA / -2,0
+ TAD TWOPEX
+ DCA I AUTO10
+ TAD T20SIN
+ TAD TWOPEY
+ DCA I AUTO10
+
+
+
+ TAD T20COS
+ TAD T30SIN
+ CIA
+ TAD TWOPEX /FOURTH POINT
+ DCA I AUTO10 / -2,-3
+ TAD T30COS
+ CIA
+ TAD T20SIN
+ TAD TWOPEY
+ DCA I AUTO10
+
+
+
+
+ TAD T20SIN
+ CIA /NEXT
+ TAD TWOPEX / 0,-2
+ DCA I AUTO10
+ TAD T20COS
+ CIA
+ TAD TWOPEY
+ DCA I AUTO10
+
+FLAM2, CLA CLL IAC RAL /NOW THE FLAME BIT. CHECK FOR POWER ON
+ AND INTWRD
+ SNA CLA
+ JMP TWOCON /NO, FORGET IT
+ TAD TWOOUT /NOT ALLOWED IF EXPLODING
+ SZA CLA
+ JMP TWOCON
+
+ TAD TWFG1 /SET THE 1-3 FLICKER AS WITH #1
+ SNA
+ CLA CLL CMA RAL
+ DCA TWFG1
+
+ ISZ TWFG1 /ALSO THE LENGHT VARIATION
+ JMP TWOCON
+
+ TAD TWFG2 /EVERY OTHER TIME LONG
+ CMA
+ DCA TWFG2
+ /FLAME TIP AT EITHER
+ TAD TWFG2 / 0,-3
+ SNA CLA /OR
+ TAD T20SIN / 0,-5
+ TAD T30SIN
+ CIA
+ TAD TWOPEX
+ DCA I AUTO10
+ TAD TWFG2
+ SNA CLA
+ TAD T20COS
+ TAD T30COS
+ CIA
+ TAD TWOPEY
+ DCA I AUTO10
+
+ TAD T20SIN /NOW BACK UP TO THE SHIP
+ CIA
+ TAD TWOPEX
+ DCA I AUTO10
+ TAD T20COS
+ CIA
+ TAD TWOPEY
+ DCA I AUTO10
+
+ CLA CLL CMA RAL /ADD -2 TO POINT COUNT
+
+
+
+
+TWOCON, TAD M10 /SET POINT COUNT TO -8 OR -10
+ DCA TWOCNT
+
+ TAD T30SIN /CONTINUE WITH DISPLAY FILE
+ CIA /NEXT POINT AT 2,-3
+ TAD T20COS
+ TAD TWOPEX
+ DCA I AUTO10
+ TAD T30COS
+ TAD T20SIN
+ CIA
+ TAD TWOPEY
+ DCA I AUTO10
+
+
+
+ TAD T20COS /NEXT POINT
+ TAD TWOPEX /
+ DCA I AUTO10 / 2,0
+ TAD T20SIN
+ CIA
+ TAD TWOPEY
+ DCA I AUTO10
+
+ TAD T20COS /AND THE NEXT AT
+ TAD T20SIN
+ TAD TWOPEX / 2,2
+ DCA I AUTO10
+ TAD T20SIN
+ CIA
+ TAD T20COS
+ TAD TWOPEY
+ DCA I AUTO10
+
+ TAD T30SIN
+ TAD TWOPEX
+ DCA I AUTO10
+ TAD T30COS /AND THE LAST AT
+ TAD TWOPEY /
+ DCA I AUTO10 / 0,3
+
+ JMP I IFILDS /NOW TO DISPLAY THE WHOLE MESS
+IFILDS, FILDIS
+
+TWFG1, 0 /FLIK THE FLAME
+TWFG2, 0 /LONG OR SHORT
+
+
+
+/
+/ HERE TO DISPLAY THE TWO SHIPS. CHECK FIRST FOR COLLISION
+/ AND THEN SET THE TWO PAIRS OF COORDENATES FOR THE END
+/ POINTS AND CALL THE "VECTOR GENERATOR" TO DRAW THE DOTS
+/ IN BETWEEN. WHEN THE COUNT OVERFLOWS DO THE SAME FOR
+/ NUMBER TWO. THEN EXIT TO DISPLAY ALL THE PROJECTILES.
+/
+
+ *1400
+
+FILDIS, CLA CLL /ALL SET TO GO
+ JMS I COLIDE /TEST FOR COLLISION FIRST
+/ DSB 1 /IF NO COLLISION
+ TAD ONEFLG /SKIP NUMBER ONE IF NOT IN NORMAL
+ SZA CLA /SPACE
+ JMP TWODIS
+
+ TAD ONEFIL /SET UP POINTERS TO DISPLAY FILE
+ DCA AUTO10 /FOR NUMBER ONE
+ TAD ONECNT /ALONG WITH VECTOR COUNT
+ DCA AUTO11
+ TAD I AUTO10 /SET OUT THE FIRST POINT PAIR
+ DCA XONEDS
+ TAD I AUTO10
+ DCA YONEDS
+ TAD ONEOUT /NORMAL DISPLAY OR EXPLOSION?
+ SZA CLA
+ JMP I IONEEX /GO ELSE WHERE FOR EXPLOSION
+
+FILONE, TAD I AUTO10 /STEP TO NEXT PAIR OF POINTS
+ DCA XTWODS /SET X AND Y TO NEW POINT
+ TAD I AUTO10
+ DCA YTWODS
+ JMS I VECTOR /CALL THE DOT DRAWING MACHINE
+ ISZ AUTO11
+ SKP /COUNT
+ JMP TWODIS /DO NUMBER TWO ON OVERFLOW
+ TAD XTWODS /SWAP POINTS FOR NEXT PAIR
+ DCA XONEDS
+ TAD YTWODS /THE GENERATOR DRAWS FROM ONE
+ DCA YONEDS /TOWARDS TWO
+ JMP FILONE
+
+
+
+
+TWODIS, TAD TWOFLG /HERE TO DO NUMBER TWO
+ SZA CLA /BUT NOT IF IN HYPER SPACE
+ JMP I IPRODS
+
+ TAD TWOFIL /SET UP FILE POINTER AS IN ONE
+ DCA AUTO10
+ TAD TWOCNT /AND THE COUNT
+ DCA AUTO11
+ TAD I AUTO10 /I SUPPOSE THIS COULD BE A SUBROUTINE TOO
+ DCA XONEDS
+ TAD I AUTO10
+ DCA YONEDS
+ TAD TWOOUT /IS IT EXPLODING?
+ SZA CLA
+ JMP I ITWOEX /YES, HOW EXCITING
+
+TWDLOP, TAD I AUTO10 /NO HOW DULL, STICK IN NEXT PAIR OF
+ DCA XTWODS /POINTS
+ TAD I AUTO10
+ DCA YTWODS /AND CALL THE VECTOR SEQUENCE
+ JMS I VECTOR
+ ISZ AUTO11
+ JMP .+3
+
+ JMP I .+1 /WHEN COUNT OVERFLOWS GO ON TO
+IPRODS, PRODIS /DO THE PROJECTILE THING
+
+ TAD XTWODS /OTHERWISE SWAP ON TO THE NEXT PAIR
+ DCA XONEDS /OF POINTS
+ TAD YTWODS
+ DCA YONEDS
+ JMP TWDLOP
+
+COLIDE, COLLID
+IONEEX, ONEEXP
+ITWOEX, TWOEXP
+
+
+
+/
+/ THIS IS THE SO CALLED "VECTOR GENERATOR" WHICH DRAWS A
+/ SERIES OF DOTS FROM XONEDS,YONEDS TO XTWODS,YTWODS.
+/ THE COORDINATE COMPONENTS ARE DIVIDED INTO FOURTHS AND
+/ FOUR DOTS DRAWN ON THE SCOPE SCREEN. NOTE THAT NO DOT
+/ IS DRAWN AT XONEDS,YONEDS. THIS IS COMPENSATED FOR ELSEWHERE.
+/
+
+DISPLY, 0 /ENTER TO DRAW A FOUR POINT VECTOR
+ CLA
+ TAD XONEDS /FROM XONEDS,YONEDS
+ CIA /TO XTWODS,YTWODS
+ TAD XTWODS /DIVIDE COORDINATE DIFERENCES INTO
+ JMS DISHFT /FOURTHS
+ DCA DIXTEM /AND STORE INCREMENT
+ TAD YONEDS
+ CIA
+ TAD YTWODS
+ JMS DISHFT /FOURTHS
+ DCA DIYTEM
+ TAD M4 /FOR FOUR DOTS
+ DCA DISCNT
+
+DISLOP, TAD XONEDS /ADD INCREMENT TO CURRENT X AND Y
+ TAD DIXTEM
+ DCA XONEDS /NOTE THAT THIS ROUTINE DESTROYS
+ TAD YONEDS /XONEDS AND YONEDS
+ TAD DIYTEM
+ DCA YONEDS
+ TAD XONEDS
+/ RTR /DIVIDE BY 8 TO FIT SCREEN SIZE
+/ RAR
+ DXC DXL /SET X VALUE
+ CLA
+ TAD YONEDS /DO THE SAME FOR Y
+/ RTR
+/ RAR
+ DYC DYL DIS /AT LAST SOMETHING TO SEE!!
+ CLA
+ ISZ DISCNT /DONE YET?
+ JMP DISLOP /NOPE
+ JMP I DISPLY /YUP
+
+
+DISHFT, 0 /A GENERALIZED SHIFT ROUTINE CALLED
+ CLL /FROM EVERYWHERE TO DIVIDE THE
+ SPA /AC BY FOUR WITH AN ASR RIGHT
+ CML IAC /NOTE THAT NEGATIVE NUMBERS ARE
+ RAR /ROUNDED UPWARDS (TOWARD ZERO)
+ CLL /TO MAKE IT COME OUT RIGHT
+ SPA
+ CML IAC /EVEN SO THERE ARE SOME ROUNDING ERRORS
+ RAR /SOMEWHERE. SO MUCH FOR 12 BIT MACHINES
+ JMP I DISHFT
+
+
+
+/
+/ HERE TO DISPLAY ALL THE PROJECTILES AND TEST FOR HITS.
+/ THE PROJECTILE DISPLAY FILE IS SEARCHED FOR PROJECTILES WITH
+/ NON-ZERO COUNTS AND WHEN ONE IS FOUND THE POSITION IS
+/ UPDATED BY THE VELOCITY, THE POINT DISPLAYED AND TESTED FOR
+/ A HIT.
+/
+
+ *1600
+
+PRODIS, CLA CLL / BEGIN DISPLAY OF THE PROJECTILES
+ TAD BUFST /POINT TO BEGINNING OF DISPLAY FILE
+ DCA BUFTMP
+/ DSB 2 /SET EXTRA BRIGHT FOR SINGLE POINTS
+
+PROLOP, TAD I BUFTMP /PICK UP NEXT COUNT
+ SNA
+ JMP EXPIRE /THIS ONE IS DEAD - GO TO THE NEXT
+ IAC /INCREMENT COUNT AND REPLACE
+ DCA I BUFTMP
+ ISZ BUFTMP /BUMP POINTER TO X VELOCITY
+ TAD I BUFTMP
+ ISZ BUFTMP /THEN TO XPOSITION AND UPDATE X POSITION
+ TAD I BUFTMP /WITH THE VELOCITY WHICH IS CONSTANT
+ DCA I BUFTMP
+ TAD I BUFTMP
+ DCA PROX /AND STORE X POSITION FOR DISPLAY AND TEST
+ ISZ BUFTMP /NOW TO Y POSITION AND VELOCITY
+ TAD I BUFTMP
+ ISZ BUFTMP
+ TAD I BUFTMP /SAME LITTLE GAME
+ DCA I BUFTMP
+ TAD I BUFTMP
+ DCA PROY /STORE THE NEW Y VALUE
+
+ TAD PROX /DISPLAY THE POINT WITH
+/ RTR /THE SAME SHIFT AS FOR THE SHIPS
+/ RAR /FOR THE SMALL SCREEN
+ DXC DXL
+ CLA
+ TAD PROY
+/ RTR /
+/ RAR
+ DYC DYL DIS /THERE IT IS!!
+ CLA
+ JMS I CHKOUT /TEST FOR A HIT
+ ISZ BUFTMP /MOVE POINTER ON AND TEST FOR END
+ TAD BUFTMP /OF BUFFER
+ TAD BUFLIM
+ SZA CLA
+ JMP PROLOP /NOT AT END - CONTINUE
+
+
+/
+/ HERE AT THE END OF THE PROJECTILE DISPLAY. IF THE GAMOVR
+/ FLAG IS SET, GO ON TO THE MESSAGE DISPLAY - VICTORY LAP
+/ SECTION. OTHERWISE PICK UP THE REMAINING CLOCK COUNT
+/ TO GIVE THE FANS SOMETHING TO LOOK AT, AND MOVE THE
+/ ELECTRON BEAM TO A LOWER CORNER. THE COUNT DISPLAYED
+/ IN THE AC IS THE NUMBER OF 100 USEC CLOCK TICKS REMAINING
+/ WHEN THIS CODE IS REACHED BEFORE THE NEXT UPDATE WOULD
+/ BEGIN. TURNS OUT THAT ROUGHLY 2/3 OF THE CPU IS LEFT
+/ OVER SHOULD ANYONE WANT TO DO ANYTHING VERY FANCY.
+/
+
+
+FINISH, TAD GAMOVR /IS THIS THE VICTORY LAP OR WHAT?
+ SZA CLA
+ JMP I ENDGAM /YES, GO TO PUT UP THE MESSAGE
+/ TAD M400 /MOVE THE BEAM OFF SCREEN
+/ DYC DYL
+ CLA CLL
+/ DXC DXL
+ TAD INTCNT /PICK UP THE COUNT
+ CIA
+ JMP .
+
+ENDGAM, JOBLOP
+
+
+EXPIRE, TAD BUFTMP /HERE TO ADVANCE THE BUFFER
+ TAD P5 /POINTER TO THE NEXT PROJECTILE
+ DCA BUFTMP /UNLESS THE END
+ TAD BUFTMP /OF THE BUFFER
+ TAD BUFLIM /IS REACHED
+ SZA CLA /IN WHICH CASE
+ JMP PROLOP /IT
+ JMP FINISH /QUITS
+
+BUFST, DISBUF+101
+BUFLIM, -DISBUF-175
+CHKOUT, CHECK
+
+RESE1, 0 /THIS IS CALLED TO SET THE POINTER
+ TAD MRES /(AUTO16) TO THE NEXT FREE SLOT
+ DCA RESCNT /FOR A PROJECTILE LAUNCH. 12 POSSIBLE
+
+RESLOP, TAD RESPNT /MOVE THE POINTER TO THE NEXT SLOT
+ TAD P5
+ DCA RESPNT
+ TAD RESPNT /RESTE IF AT END OF BUFFER
+ TAD BUFLIM
+ SZA CLA
+ JMP RESCON
+ TAD BUFST
+ DCA RESPNT
+
+RESCON, TAD I RESPNT /FIND A HOLE YET?
+ SNA CLA
+ JMP RESFND /YES, SET UP AUTO16
+ ISZ RESCNT /NO COUNT
+ JMP RESLOP /AND TRY AGAIN
+ HLT /NO HOLES AT ALL?
+
+RESFND, CMA /BACK THE POINTER FOR AUTO INDEXING
+ TAD RESPNT
+ DCA AUTO16
+ JMP I RESE1
+
+MRES, -14
+RESCNT, 0
+RESPNT, 0
+
+SETBUF, 0
+ CMA /THIS ROUTINE IS CALLED FROM THE
+ TAD BUFST /STARTING SEQUENCE TO INITIALIZE ALL
+ DCA AUTO16 /THE BUFFER POINTERS AND SO ON
+ TAD BUFST
+ DCA BUFTMP
+ TAD BUFST
+ DCA RESPNT
+ TAD BUFST
+ DCA SETPNT
+SETLOP, DCA I SETPNT
+ ISZ SETPNT
+ TAD SETPNT
+ TAD BUFLIM
+ SZA CLA
+ JMP SETLOP
+ JMP I SETBUF
+
+SETPNT, 0
+
+
+
+/
+/ THIS HERE NOW THING CHECKS THE COORDINATES OF THE MOST RECENTLY
+/ DISPLAYED PROJECTILE AGAINST THOSE OF THE SHIPS ON THE SCREEN.
+/ IF WITH A COLLISION LIMIT A HIT IS RECORDED AND THE LIFE
+/ COUNT OF THE PROJECTILE ZEROED TO REMOVE IT. A HIT SHIP
+/ IS SUITABLY FLAGGED
+/
+
+ *2000
+
+CHECK, 0 /HERE TO TEST FOR A PROJECTILE HIT
+ TAD ONEFLG /CANT HIT SOMETHING IN HYPERSPACE
+ SZA CLA
+ JMP CHECK2
+ TAD ONEOUT /OR SOMETHING THAT'S BEEN HIT
+ SZA CLA
+ JMP CHECK2
+
+ TAD PROX /CHECK X COORDINATES OF SHIP ONE
+ CIA /AND PROJECTILE
+ TAD ONEPEX /THIS SORT OF THING IS WHY THE
+ SPA /COORDINATES HAVE TO BE MAINTAINED TO 12
+ CIA /BITS
+ TAD LIMIT /CLOSE ENOUGH?
+ SMA CLA
+ JMP CHECK2 /IF X ISN' CLOSE ENOUGH THEN NO HIT
+ TAD PROY /X WAS CLOSE ENOUGH, HOW ABOUT Y?
+ CIA
+ TAD ONEPEY
+ SPA
+ CIA
+ TAD LIMIT
+ SMA CLA
+ JMP CHECK2 /NO HIT
+
+ TAD MEXP /DEPOSIT EXPLOSION COUNT IN ONEOUT
+ DCA ONEOUT /ALL THAT IS NECESSARY
+ JMS CUTOUT /REMOVE PROJECTILE
+
+
+
+
+CHECK2, TAD TWOFLG /NO HIT ON NUMBER ONE, TRY NUMBER TWO
+ SZA CLA
+ JMP I CHECK /BUT NOT IF IN HYPERSPACE
+ TAD TWOOUT /OR IF ALREADY HIT
+ SZA CLA
+ JMP I CHECK
+
+ TAD PROX /CHECK X'S FIRST
+ CIA
+ TAD TWOPEX
+ SPA /GET ABSOLUTE VALUE OF DIFFERENCE
+ CIA
+ TAD LIMIT /AND TEST MAGNITUDE AGAINST PROXIMITY
+ SMA CLA /LIMIT
+ JMP I CHECK /NOWHERE NEAR CLOSE
+
+ TAD PROY /NYAH, NYAH
+ CIA /TRY THE Y'S
+ TAD TWOPEY
+ SPA
+ CIA /ABSOLUTE VALUE OF DIFFERENCE
+ TAD LIMIT
+ SMA CLA
+ JMP I CHECK /CLEAN MISS!
+
+ TAD MEXP /HIT ON TWO - END EVERYTHING BY SETTING
+ DCA TWOOUT /TWOOUT TO NON-ZERO EXPLOSION COUNT
+ JMS CUTOUT
+ JMP I CHECK /EXIT AFTER DESTOYING PROJECTILE
+
+LIMIT, -120 /PROXIMITY LIMIT FOR WHAT CONSTITUTES A HIT
+
+CUTOUT, 0 /THIS ROUTINE ZEROES OUT THE MOST RECENTLY
+ TAD M4 /DISPLAYED PROJECTILE BY ZEROEING THE
+ TAD BUFTMP /COUNT
+ DCA CUTPNT
+ DCA I CUTPNT
+ JMP I CUTOUT
+
+CUTPNT, 0
+
+
+
+/
+/ THIS ROUTINE IS CALLED TO TEST FOR A COLLISION BETWEEN THE
+/ TWO SHIPS. THE COORDINATES OF BOTH ARE COMPARED
+/ AND IFF SUFFICIENTLY CLOSE BOTH ARE DESTROYED BY SETTING
+/ THEIR EXPLOSION COUNTS NON-ZERO.
+/
+
+
+COLLID, 0 /HERE TO TEST FOR COLLISION
+ TAD ONEFLG /NO TEST IF EITHER SHIP IS IN
+ SZA CLA /HYPERSPACE OR EXPLODING
+ JMP I COLLID
+ TAD TWOFLG
+ SZA CLA
+ JMP I COLLID
+ TAD ONEOUT
+ SZA CLA
+ JMP I COLLID
+ TAD TWOOUT
+ SZA CLA
+ JMP I COLLID
+
+ TAD ONEPEX /BOTH SHIPS AVAILABLE FOR COLLISION
+ CIA /CHECK X COORDINATES FIRST
+ TAD TWOPEX
+ SPA /GET ABSOLUTE VALUE OF DIFFERENCE
+ CIA
+ TAD COLLIM /CLOSE ENOUGH?
+ SMA CLA
+ JMP I COLLID /NOPE, FORGET IT
+
+ TAD ONEPEY /YES, NOW TRY THE Y COORDINATES
+ CIA
+ TAD TWOPEY
+ SPA
+ CIA /GET MAGNITUDE ONLY
+ TAD COLLIM
+ SMA CLA /CLOSE ENOUGH?
+ JMP I COLLID
+ TAD MEXP /YES, SET BOTH EXPLOSION COUNTS
+ DCA ONEOUT
+ TAD MEXP
+ DCA TWOOUT
+ JMP I COLLID
+
+COLLIM, -300
+
+
+/
+/ THIS ROUTINE IS CALLED TO SET ONE OF THE TWO SHIPS INTO
+/ HYPERSPACE. ON ENTRY THE AC=-1 FOR SHIP #1, 0 FOR SHIP
+/ NUMBER 2. THE LOCATION CLOCK IS USED FOR A RANDOM
+/ ADDRESS POINTER FROM WHICH WILL BE DRAWN THE
+/ VARIOUS PARAMETERS FOR REENTRY.
+/
+
+ *2200
+
+HYPSET, DCA RTNFLG /HERE WITH AC=-1 OR 0
+ TAD RTNFLG /SET UP LIST POINTER
+ SZA CLA
+ TAD ONEDIF /TO APPROPRIATE SHIP FILE
+ TAD TWOLST
+ DCA AUTO15
+
+ CLCA /SET UP "RANDOM NUMBER GENERATOR"
+ /USE CLOCK COUNTER FOR THAT PURPOSE
+ DCA AUTO17
+ TAD I AUTO17 /PICK UP FIRST THE AMOUNT OF TIME
+ AND TIMOUT /OUT OF NOMAL SPACE LIMITED TO -777
+ CIA /UPDATE CYCLES ( ABOUT 15 SECONDS)
+ DCA I AUTO15 /AND STORE IN ONEOUT OR TWO OUT
+
+ TAD I AUTO17 /THE NEXT RANDOM NUMBER BECOMES THE
+ JMS I THEADJ /ANGLE OR ORIENTATION ON REENTRY
+ DCA I AUTO15
+ TAD I AUTO17 /AND THE NEXT BECOMES THE X VELOCITY
+ JMS VEESET /COMPONENT
+ DCA I AUTO15
+ TAD I AUTO17 /AND THEN THE Y COMPONENT
+ JMS VEESET
+ DCA I AUTO15
+ TAD I AUTO17
+ DCA I AUTO15
+
+ TAD I AUTO17
+ DCA I AUTO15
+
+ TAD I AUTO17 /FINALLY SEE IF RETURN WILL BE SUCCESSFLY
+ AND TIMOUT
+ TAD MHYP /ABOUT 3/4 CHANCE
+ SMA CLA
+ JMP HYPRET /OK
+ TAD RTNFLG /THIS IS THE ONE TIME IN FOUR. SET
+ SZA CLA /UP FOR EXPLOSION ON REENTRY
+ TAD ONEDIF
+ TAD OUTLOC
+ DCA VEESET
+ TAD MEXP
+ DCA I VEESET
+
+HYPRET, ISZ RTNFLG
+ JMP I TWORTN
+ JMP I ONERTN
+
+TIMOUT, 777
+ONEDIF, ONEFLG-TWOFLG
+TWOLST, TWOFLG-1
+RTNFLG, 0
+ONERTN, TWOUP
+TWORTN, ONESET
+OUTLOC, TWOOUT
+MHYP, -200
+
+
+
+
+VEESET, 0 /HERE TO LIMIT VELOCITY COMPONENTS
+ CLL
+ SPA /GET MAGNITUDE
+ CML
+ AND HM177 /LIMIT TO 177
+ SZL CLL
+ CIA
+ JMP I VEESET /AND EXIT
+
+HM177, 177
+
+ONEEXP, CLA CLL /HERE TO DISPLAY SHIP NUMBER ONE AS
+ TAD ONETHE /AN EXPLOSION
+ TAD INCONE /FIRST ROTATE IT BY A GOOD DOLLOP
+ DCA ONETHE
+ JMS I IXPDIS /THEN CALL THE EXPLOSION GENERATOR
+ ISZ ONEOUT /DONE WITH THE EXPLOSION?
+ JMP I NOWTWO /NO, NORMAL RETURN
+
+ IAC /YES, SET INTO PSEUDO HYPER SPACE
+ DCA ONEFLG
+ IAC /DISABLE RETURN FROM HYPER SPACE
+ DCA ONEFIN
+
+ TAD TWOFIN /IS NUMBER TWO STILL AROUND?
+ SNA CLA
+ JMP I NOWTWO /YES, RETURN
+ JMP I TIEUP /NO, TIE BALL GAME
+
+
+
+TWOEXP, CLA CLL /HERE TO DISPLAY SHIP NUMBER TWO
+ TAD TWOTHE /AS AN EXPLOSION. BASH IT AROUND
+ TAD INCTWO
+ DCA TWOTHE
+ JMS I IXPDIS /THEN DISPLAY IT
+ ISZ TWOOUT /DONE WITH EXPLOSION?
+ JMP I NOWPRO /NO, NORMAL RETURN
+
+ IAC /YES, SEND INTO PSEUDO HYPER SPACE
+ DCA TWOFLG
+ IAC /DISABLE NORMAL RETURN FROM HYPERSPACE
+ DCA TWOFIN
+ /CHECK NUMBER ONE
+ TAD ONEFIN
+ SZA CLA /STILL ALIVE AND WELL?
+ JMP I TIEUP /NO, TIE GAME
+ JMP I NOWPRO /YES, CONTINUE ON
+NOWTWO, TWODIS
+NOWPRO, PRODIS
+TIEUP, NOWIN
+IXPDIS, EXPDIS
+INCONE, 55
+INCTWO, 55
+
+
+
+/
+/ HERE TO DISPLAY THE FIGURE POINTED TO BY AUTO10 AS
+/ AN EXPLOSION. THIS WORKS THE SAME WAY AS THE NORMAL
+/ DISPLAY ROUTINE EXCEPT THAT THE COORDINATE INCREMENTS
+/ ARE INVERTED TURNING THE FIGURE INSIDE OUT FOR S
+/ A SORT OF CLOBBY EXPLOSION.
+/
+
+ *2400
+
+EXPDIS, 0 /HERE TO DISPLAY A FIGURE INSIDE OUT
+ TAD I AUTO10 /WITH THE POINTERS AND COUNTS ALREADY
+ DCA XTWODS /SET UP BY FILDIS OR TWODIS
+ TAD I AUTO10 /STICK NEXT TWO POINTS INTO LINE
+ DCA YTWODS
+
+ TAD XTWODS
+ CIA /CALCULATE INCREMENT THE WRONG WAY
+ TAD XONEDS
+ DCA DIXTEM /AND STORE
+ TAD YTWODS
+ CIA
+ TAD YONEDS
+ DCA DIYTEM /SAME FOR Y
+
+ TAD M4 /4 DOTS IN THE VECTOR"
+ DCA DISCNT /COULD HAVE CALLED THE OTHER
+ /VECTOR GENERATOR I SUPPOSE
+EXPLOP, TAD XONEDS
+ TAD DIXTEM /ADD X AND Y INCREMENTS TO THE RUNNING
+ DCA XONEDS /TOTALS AND DISPLAY THE RUNNING
+ TAD YONEDS /TOTALS NORMAL SIZE
+ TAD DIYTEM
+ DCA YONEDS
+
+ TAD XONEDS
+/ RTR /COULD MAKE TWICE AS BIG BY NOP-ING
+/ RAR /THE RAR'S BUT THE SCREEN IS SMALL ENOUGH
+ JMS I IVCLDX /AS IT IS
+ CLA
+ TAD YONEDS
+/ RTR
+/ RAR
+ JMS I IVCLDY
+/ DISD
+/ JMP .-1
+/ DIXY
+
+ CLA
+ ISZ DISCNT /DONE 4 DOTS?
+ JMP EXPLOP /NO
+
+ ISZ AUTO11 /DONE ALL VECTORS IN THE FILE?
+ SKP
+ JMP I EXPDIS /YES, EXIT
+
+ TAD XTWODS /NO SWAP TO NEXT PAIR OF POINTS
+ DCA XONEDS
+ TAD YTWODS
+ DCA YONEDS
+ JMP EXPDIS+1
+
+
+
+
+/
+/ VEELIM IS THE SCALING ROUTINE FOR VELOCITY COMPONENTS.
+/ THE COMPONENTS ARE SCALED TO REMAIN IN THE RANGE 140
+/ TO -140. THIS IS NECESSARY TO AVOID ASTRONOMICAL SPPED
+/ BUILDUP ON THE SMALL SCREEN. UNFORTUNATELY THE X AND Y
+/ COMPONENTS ARE SCALED SEPARATELY WHICH GIVES SLIGHT BUT
+/ NOTICABLE DISTORTIONS IN DIAGONAL FLIGHT PATHS. IN THE
+/ NORMAL HEAT OF THE BATTLE NO ONE WILL REALLY NOTICE.
+/
+
+
+VEELIM, 0 /ENTER TO SCALE VELOCITY HELD IN
+ DCA VEEHLD /AC
+ TAD VEEHLD
+ SMA /BRANCH FOR POSITIVE OR NEGATIV
+ JMP VEEPOS
+ TAD VEEMAX
+ SMA CLA /GREATER THAN MAXIMUM POSITIVE?
+ JMP VEECLR /NO
+ TAD VEEMIN /I MEAN MAXIMUM NEGATIVE - YES SET
+ JMP I VEELIM /TO MAX NEGATIV
+
+VEEPOS, TAD VEEMIN /GREATER THAN MAX?
+ SPA CLA
+ JMP VEECLR /NO
+ TAD VEEMAX /YES SET TO MAX
+ JMP I VEELIM
+
+VEECLR, TAD VEEHLD /IT WAS IN RANGE ALL ALONG
+ JMP I VEELIM
+
+VEEHLD, 0
+VEEMIN, -140
+VEEMAX, 140
+
+THEAJI, 0 /HERE TO ADJUST THE ANGLE TO A RANGE
+ SMA /0-550 OR 0-360 DEGREES. THIS IS
+ JMP .+3 /NECESSARY TO INSURE THAT PUSHDOWN OVERFLOW
+ TAD P550 /WILL NOT HAPPEN IN THE SINE AND COSINE
+ JMP .-3 /ROUTINES. THIS SIMPLY TAKES THE AC
+ TAD M550 /MODULO 360 AND EXITS
+ SMA
+ JMP .-2
+ TAD P550 /FOLLOW IT THROUGH AND SEE IF IT DOESN'T
+ JMP I THEAJI
+
+
+
+/
+/ ONE OF THESE ROUTINE IS ENTERED WHEN A WINNER IS DECLARED.
+/ THE ADDRESS OF THE VICTORY MESSAGE IS PLACED IN MESS AND
+/ THE GAMOVR FLAG SET TO CAUSE A BRANCH TO JOBLOP WHEN THE
+/ DISPLAY CYCLE IS COMPLETED. THE ROUTINE WILL THEN DISPLAY
+/ THE APPROPRIATE MESSAGE OVER THE REMAINING SHIPS IF
+/ ANY UNTIL THE KEYBOARD IS MOLESTED OR THE CLOCK RUNS OUT
+/ AND THE NEXT DISPLAY UPDATE CYCLE IS SET. AT ANY RATE THE
+/ PROGRAM WILL REACH HERE ONLY WHEN SOMEONE HAS BITTEN THE
+/ INTERGALACTIC DUST.
+/
+
+
+ONEWIN, 0 /THIS IS CALLED WHEN TWOFIN IS SET
+ TAD MES1 /AND ONE FIN IS NOT. SET ONE TO VICTOR
+ DCA MESS /AND SET GAMOVR FLAG
+ IAC
+ DCA GAMOVR
+ JMP I ONEWIN /THEN RETURN TO UPDATE CYCLE
+
+TWOWIN, 0 /THIS IS CALLED WHEN ONEFIN IS SET
+ TAD MES2 /AND TWO FIN IS NOT
+ DCA MESS /SET ALSO GAMOVR
+ IAC
+ DCA GAMOVR
+ JMP I TWOWIN
+
+NOWIN, TAD MES4 /GET HERE WHEN BOTH ONEFIN AND TWOFIN
+ DCA MESS /ARE SET .
+ IAC
+ DCA GAMOVR /NOBODY EVER REALLY WINDS
+ /UP THE WINNER IN THESE THINGS
+JOBLOP,
+/ DSB 1 /THIS IS ENTERED FROM FINISH WHEN
+ TAD MES0 /GAMOVR IS SET AND SERVES TO DISPLAY
+ JMS I MESOUT /THE VICTORY MESSAGE ON THE SCREEN
+ TAD MESS /USING THE CHARACTER GENERATOR SOMEWHAT
+ JMS I MESOUT /FURTHER ON UNTIL THE GAME IS RESTARTED
+ TAD MES5 /OR UNTIL THE INTERRUPT COUNT OVERFLOWS
+ JMS I MESOUT /AND THE UPDATE CYCLE IS RESTARTED
+ TAD MES3
+ JMS I MESOUT
+FINITO, JMP JOBLOP
+
+MES0, MESS0
+MES1, MESS1
+MES2, MESS2
+MES3, MESS3
+MES4, MESS4
+MES5, MESS5
+MESS, 0
+
+
+
+/
+/ THE FOLLOWING ARE THE SINE AND COSINE ROUTINES CUSTOMIZED
+/ FOR THIS PROGRAM FROM ANOTHER I WORKED ON. CALL EITHER
+/ SINE OR COSINE WITH ANGLE IN DEGREES IN AC. THE ARGUEMENT
+/ IS REDUCED THROUGH RECURSION UNTIL BETWEEN 0-89 DEGREES
+/ AND THEN A TABLE LOOKUP DONE TO OBTAIN THE VALUE. IT TAKES
+/ UP A FAIR AMOUNT OF SPACE BUT IT WORKS JUST FASTER
+/ THAN SHEEP. THE COSINE CALL JUST TRANSFORMS THE ARGUEMENT
+/ THROUGH SOME TRIGONOMETRIC GARBAGE AND CALLS THE SINE
+/ ROUTINE. NOTE THAT CALLING EITHER ROUTINE WITH TOO
+/ LARGE AN ARGUEMENT WILL CAUSE PUSHDOWN OVERFLOW AND THEN
+/ ALL HELL WILL BREAK LOOSE. THE ORIGINAL ROUTINE FROM WHICH
+/ THIS WAS STOLEN HAD FULL WORD PRECISION.
+/
+
+ *6400
+
+SINEIN, 0 /I REALLY CANT BRING MYSELF TO COMMENT
+ DCA SINARG /THIS. IT'S VERY STRAIGHFORWARD
+ TAD SINEIN
+ DCA I SINPSH
+ ISZ SINPSH
+ TAD SINARG
+ SZA
+ JMP SINNG2
+
+SINPOP, CLA CLL CMA
+ TAD SINPSH
+ DCA SINPSH
+ TAD I SINPSH
+ DCA SINEIN
+ TAD SINARG
+ JMP I SINEIN
+
+SINNG2, SMA
+ JMP SINPOS
+ CIA
+ JMS SINEIN
+
+SINNEG, CIA
+ DCA SINARG
+ JMP SINPOP
+
+SINPOS, TAD M264
+ SPA
+ JMP .+2
+ JMP SINNEG-1
+ TAD P132
+ SPA
+ JMP SINELK
+ SZA CLA
+ JMP .+3
+ TAD P37
+ JMP SINNEG+1
+
+ TAD SINARG
+ TAD M264
+ JMP SINNEG-1
+
+SINELK, TAD P132
+ TAD SINTAB
+ DCA SINEIN
+ TAD I SINEIN
+ DCA SINARG
+ JMP SINPOP
+
+
+
+
+SINARG, 0
+SINPSH, SINLST
+SINLST, 0
+ 0
+ 0
+ 0
+ 0
+ 0
+
+SINTAB, SINES-1
+
+COSINI, 0
+ CIA
+ TAD P132
+ JMS SINEIN
+ JMP I COSINI
+
+
+
+
+SINES, 00 /1
+ 01 /2
+ 01 /3
+ 02 /4
+ 02 /5
+ 03 /6
+ 03 /7
+ 04 /8
+ 05 /9
+ 05 /10
+ 06 /11
+ 06 /12
+ 07 /13
+ 07 /14
+ 10 /15
+ 10 /16
+ 11 /17
+ 11 /18
+ 12 /19
+ 12 /20
+ 13 /21
+ 13 /22
+ 14 /23
+ 15 /24
+ 15 /25
+ 16 /26
+ 16 /27
+ 17 /28
+ 17 /29
+ 20 /30
+ 20 /31
+ 20 /32
+ 21 /33
+ 21 /34
+ 22 /35
+ 22 /36
+ 23 /37
+ 23 /38
+ 24 /39
+ 24 /40
+ 25 /41
+ 25 /42
+ 25 /43
+ 26 /44
+ 26 /45
+ 27 /46
+ 27 /47
+ 27 /48
+ 30 /49
+ 30 /50
+ 30 /51
+ 31 /52
+ 31 /53
+ 31 /54
+ 32 /55
+ 32 /56
+ 32 /57
+ 33 /58
+ 33 /59
+ 33 /60
+ 33 /61
+ 34 /62
+ 34 /63
+ 34 /64
+ 35 /65
+ 35 /66
+ 35 /67
+ 35 /68
+ 35 /69
+ 36 /70
+ 36 /71
+ 36 /72
+ 36 /73
+ 36 /74
+ 36 /75
+ 37 /76
+ 37 /77
+ 37 /78
+ 37 /79
+ 37 /80
+ 37 /81
+ 37 /82
+ 37 /83
+ 37 /84
+ 37 /85
+ 37 /86
+ 37 /87
+ 37 /88
+ 37 /89
+
+
+
+
+MULTI, 0 /THIS IS STANDARD SINGLE PRECISION
+ CLL /MULTIPLY ROUTINE WHICH WAS ONCE
+ SPA /USED. I'VE LEFT IT IN SINCE
+ CMA CML IAC /THERE IS LOTS OF CORE LEFT OVER AND
+ DCA MULMP1 /MAYBLE SOMEDAY I'LL NEED IT TO PUT
+ DCA MULMP5 /IN A SUN OR SOMETHING. THIS IS THE
+ TAD I MULTI /STANDARD DEC SUBROUTINE WITH DIFFERENT
+ SNA /LABELS
+ JMP MULPSN+2
+ SPA
+ CMA CML IAC
+ DCA MULMP2
+ TAD MULTHR
+ DCA MULMP3
+
+MULMP4, TAD MULMP1
+ RAR
+ DCA MULMP1
+ TAD MULMP5
+ SZL
+ TAD MULMP2
+ CLL RAR
+ DCA MULMP5
+ ISZ MULMP3
+ JMP MULMP4
+ TAD MULMP1
+ RAR
+MULPSN, SZL
+ JMP MULCMP
+ DCA MULMP1
+ TAD MULMP5
+MULMPZ, ISZ MULTI
+ JMP I MULTI
+
+MULCMP, CMA CLL IAC
+ DCA MULMP1
+ TAD MULMP5
+ CMA
+ SZL
+ IAC
+ JMP MULMPZ
+
+MULTHR, 7764
+MULMP1, 0
+MULMP5, 0
+MULMP2, 0
+MULMP3, 0
+
+
+
+/
+/ SHIFTR DIVIDES THE AC BY TWO WHETHER POSITIVE OR NEGATIVE
+/ AND IS CALLED FROM VARIOUS PLACES. NOT ENTIRELY MYSTERIOUS
+/
+
+
+SHIFTR, 0
+ CLL
+ SPA
+ CML IAC
+ RAR
+ JMP I SHIFTR
+
+
+/
+/ POSCAL IS CALLED TO CALCULATE THE COORDINATE INCREMENTS
+/ NECESSARY TO PRODUCE THE SHIP FIGURES. RATHER THAN DOING
+/ A LOT OF EXPENSIVE MATH THIS DOES A QUICK PRODUCTION
+/ OF 1, 2, AND 3 TIMES THE SIN AND COSINE VALUES FOUND
+/ IN CALSIN AND CALCOS LEAVING THEM IN THE TABLE FOR
+/ ONESET AND TWOSET. IF THE SCOPE WERE ANY BETTER
+/ THIS PROBABLY WOULDN'T BE NEAR GOOD ENOUGH BUT....
+/
+
+POSCAL, 0
+ TAD CALSIN
+
+ DCA T10SIN
+ TAD T10SIN
+ CLL RAL
+ DCA T20SIN
+ TAD T10SIN
+ TAD T20SIN
+ DCA T30SIN
+
+ TAD CALCOS
+
+ DCA T10COS
+ TAD T10COS
+ CLL RAL
+ DCA T20COS
+ TAD T10COS
+ TAD T20COS
+ DCA T30COS
+ JMP I POSCAL
+
+/****************************************************************
+/ VC8-E ROUTINES
+
+
+VDIV, 0
+ SMA / SKIP IF MINUS
+ JMP VPLUS
+VMINUS, CMA IAC / COMPLEMENT
+ RTR / DIVIDE BY FOUR
+ AND P1777 / DELETE UPPER TWO BITS
+ CMA IAC
+ JMP I VDIV / RETURN
+
+VPLUS, RTR
+ AND P1777
+ JMP I VDIV
+
+/*****
+
+VCLDX, 0 / INTENSIFY LAST POINT AND LOAD NEW X VALUE
+ JMS VDIV / DIVIDE BY FOUR
+ DISD / DISPLAY READY?
+ JMP .-1 / WAIT.
+ DIXY / INTENSIFY
+ DILX / LOAD NEW X VALUE
+ JMP I VCLDX / RETURN
+
+VCLDY, 0
+ JMS VDIV / DIVIDE BY FOUR
+ DILY / LOAD NEW Y VALUE
+ JMP I VCLDY
+
+P1777, 1777
+
+
+/****************************************************************
+
+
+ *7000
+
+/GENERAL PURPOSE SYMBOL GENERATOR
+/
+CHARS, 0 /ENTRY TO PLOT CHARACTER STRING
+ DCA ADDR /STORE STRING ADDRESS
+ TAD I ADDR /FETCH DOUBLE CHARACTER
+ RTR /SHIFT
+ RTR / FOR FIRST
+ RTR / CHARACTER
+ JMS CHAR /PLOT CHARACTER
+ SKP /NORMAL RETURN -- SKIP
+ JMP I CHARS /TERMINATION RETURN -- EXIT
+ TAD I ADDR /RECALL DOUBLE CHARACTER
+ ISZ ADDR /ADVANCE STRING ADDRESS
+ JMS CHAR /PLOT CHARACTER
+ JMP CHARS+2 /NORMAL RETURN -- REPEAT
+ JMP I CHARS /TERMINATION RETURN -- EXIT
+/
+CHAR, 0 /ENTRY TO PLOT SINGLE CHARACTER
+ AND K77 /MASK OUT UPPER BITS
+ CLL RAL /MULTIPLY CODE BY TWO
+ TAD TABLE /ADD TABLE BASE ADDRESS
+ DCA POINT /CONSTRUCT POINTER TO 24-BIT CODE
+ CMA /INITIALIZE COUNTER FOR
+ DCA COUNT2 / TWO PLOT WORDS
+ TAD I POINT /FETCH FIRST PLOT WORD
+ ISZ POINT /INCREMENT POINTER FOR NEXT ONE
+ SNA /SKIP IF NOT SPECIAL CHARACTER
+ JMP SPCHAR /ELSE GO PROCESS IT
+ DCA CURPLT /SAVE CURRENT PLOT BITS
+XPLOT, TAD KM6 /INITIALIZE 6-BIT
+ DCA COUNT6 / COUNTER
+ TAD YVALUE /RESET Y TEMPORARY
+ DCA YTEMP / VALUE FOR CHARACTER
+ TAD XVALUE /OUTPUT CURRENT
+ DILX /X-VALUE TO CRT
+ TAD XINCR /INCREMENT
+ DCA XVALUE / ABSCISSA
+YPLOT, TAD CURPLT /RECALL CURRENT PLOT BITS
+ CLL RAL /GET NEXT BIT
+ DCA CURPLT /SAVE REMAINING PLOT BITS
+ SNL /SKIP IF POINT TO PLOT
+ JMP CNTINU /ELSE JUMP AHEAD
+ TAD YTEMP /OUTPUT CURRENT
+ DILY /Y-VALUE TO CRT
+ DISD / READY TO DISPLAY THE POINT?
+ JMP .-1 / NO, WE'LL WAIT.
+ DIXY / SHOOT THE BEAM!
+
+ CLA CLL /CLEAR AC
+ TAD CURPLT /RECALL CURRENT PLOT BITS
+ SNA CLA /SKIP IF POINTS REMAINING
+ JMP WRDEND /ELSE WORD IS FINISHED
+CNTINU, TAD YTEMP /INCREMENT TEMPORARY
+ TAD YINCR / Y-VALUE FOR NEXT
+ DCA YTEMP / CHARACTER STEP
+ ISZ COUNT6 /SKIP IF 6 BITS PLOTTED
+ JMP YPLOT /ELSE PLOT NEXT ONE
+ JMP XPLOT /GO UPDATE X-VALUE
+WRDEND, ISZ COUNT2 /SKIP IF ANOTHER BIT WORD
+ JMP EXIT /ELSE EXIT
+ TAD I POINT /FETCH SECOND BIT WORD
+ SZA /SKIP IF NO PLOT POINTS
+ JMP XPLOT-1 /ELSE GO PLOT THEM
+EXIT, TAD XVALUE /INCREMENT ABSCISSA
+ TAD XINCR / FOR SPACE BETWEEN
+ DCA XVALUE / SYMBOLS
+ JMP I CHAR /EXIT FROM CHAR
+/
+SPCHAR, TAD I POINT /FETCH TRANSFER VECTOR
+ DCA POINT /STORE AS INDIRECT ADDRESS
+
+ JMP I POINT /GO TO APPROPRIATE ROUTINE
+SPACE, TAD XINCR /FETCH BASIC ABSCISSA INCREMENT
+ CLL RTL /MULTIPLY BY FOUR AND
+ JMP EXIT / GO CREATE SPACE
+CRLF, TAD INITX /"CARRIAGE RETURN" RESETS X
+ DCA XVALUE / TO ITS ORIGINAL VALUE
+LF, TAD YINCR /"LINE FEED"
+ CLL RTL / DECREMENTS THE
+ CLL CIA RAL / Y-VALUE BY
+ TAD YVALUE / EIGHT SCALE
+ DCA YVALUE / STEPS
+ JMP I CHAR /EXIT FROM CHAR
+RESET, TAD INITX /"RESET" RESETS
+ DCA XVALUE / X AND Y TO
+ TAD INITY / THEIR ORIGINAL
+ JMP RESET-2 / VALUES
+TERM, ISZ CHAR /TERMINATE CODE CAUSES
+ JMP I CHAR / EXIT TO P+2
+/
+INITX, 0 /INITIAL X-VALUE
+INITY, 327 /INITIAL Y-VALUE
+XVALUE, 0 /CURRENT X-VALUE
+YVALUE, 0 /CURRENT Y-VALUE
+XINCR, 6 /BASIC X INCREMENT VALUE
+YINCR, 10 /BASIC Y INCREMENT VALUE
+YTEMP, 0 /TEMPORARY Y-VALUE
+CURPLT, 0 /CURRENT PLOT BITS
+ADDR, 0 /CURRENT STRING ADDRESS
+COUNT6, 0 /6-BIT COUNTER
+COUNT2, 0 /2-WORD COUNTER
+KM6, -6 /CONSTANT FOR COUNT6
+K77, 77 /CHARACTER CODE MASK
+POINT, 0 /TABLE POINTER
+/
+
+
+/
+TABLE, .+1 /TABLE BASE ADDRESS
+ 0 /SPECIAL CHARACTER (00)
+ TERM /TERMINATION CODE
+ 7611 / A
+ 1176
+ 7745 / B
+ 4532
+ 3641 / C
+ 4122
+ 7741 / D
+ 4136
+ 7745 / E
+ 4541
+ 7705 / F
+ 501
+ 7741 / G
+ 5173
+ 7710 / H
+ 1077
+ 4177 / I
+ 4100
+ 2040 / J
+ 4037
+ 7714 / K
+ 2241
+ 7740 / L
+ 4040
+ 7702 / M
+ 277
+ 7706 / N
+ 3077
+ 7741 / O
+ 4177
+ 7705 / P
+ 502
+ 3641 / Q
+ 6176
+ 7715 / R
+ 2542
+ 2245 / S
+ 5122
+ 177 / T
+ 100
+ 3740 / U
+ 4037
+ 1720 / V
+ 4037
+ 7730 / W
+ 3077
+ 4136 / X
+ 3641
+ 374 / Y
+ 7403
+ 6151 / Z
+ 4543
+ 7741 / [
+ 0
+ 204 / \
+ 1020
+ 4177 / ]
+ 0
+ 436 / ^
+ 400
+ 0 /SPECIAL CHARACTER (37)
+ RESET /RESET
+ 0 /SPECIAL CHARACTER (40)
+ SPACE /SPACE
+ 5600 / !
+ 0
+ 303 / "
+ 0
+ 1477 / #
+ 7714
+ 2277 / MARKER
+ 2200
+ 2313 / %
+ 6462
+ 7777 / BLOCK
+ 7777
+ 300 / '
+ 0
+ 3641 / (
+ 0
+ 4136 / )
+ 0
+ 4040 / UNDERSCORE (52)
+ 4040
+ 1034 / +
+ 1000
+ 0 /SPECIAL CHARACTER (54)
+ LF /LINE FEED
+ 1010 / -
+ 1000
+ 4000 / .
+ 0
+ 2010 / /
+ 402
+ 3641 / 0
+ 4136
+ 4442 / 1
+ 7740
+ 4261 / 2
+ 5146
+ 2145 / 3
+ 5321
+ 1710 / 4
+ 1077
+ 4745 / 5
+ 4531
+ 7750 / 6
+ 5070
+ 6111 / 7
+ 503
+ 2255 / 8
+ 5522
+ 705 / 9
+ 577
+ 2400 / :
+ 0
+ 0 /SPECIAL CHARACTER (73)
+ CRLF /CARRIAGE RETURN; LINE FEED
+ 1024 / >
+ 4200
+ 1212 / =
+ 1200
+ 4224 / <
+ 1000
+ 255 / ?
+ 300
+
+
+
+/
+/ HERE FOLLOW THE PACKED ASCII TEXTS FOR THE VARIOUS
+/ VICTORY MESSAGES. PERSONS ADVENTEROUS TO FIND THIS MIGH CARE
+/ TO TOGGLE IN SOME CUTE LITTLE MESSAGES OF THEIR OWN.
+/
+
+MESS0, 3773
+MESS5, 7340
+ 4040
+ 4040
+ 4000
+
+MESS1, 1716
+ 0500
+
+MESS2, 2427
+ 1700
+
+MESS3, 2711
+ 1623
+ 4100
+
+MESS4, 1617
+ 0217
+ 0431
+ 0000
+
+
+
+ *7400
+
+DISBUF, 0
+
+/ THE DISPLAY BUFFERS BEGIN HERE AND EXTEND UP SOMEWHERE TO
+/ AROUND 7575 OR SO.
+/
+/
+/
+/
+/
+
+
+
+
+ $
+
+////////////////////////////
+/
+/ THIS IS THE END
+/
+///////////////////////////
+
+
+
+
+
+
--- /dev/null
+/ SPACE WAR
+/
+/ INTERPLANETARY DEATH AND DESTRUCTION ON YOUR
+/ LAB-8
+/
+/
+/ KK, 21-APR-2005
+/ CHANGED THE PROGRAM FOR MY LAB-8/E
+/ IT HAS:
+/ REAL-TIME PROGRAMMABLE CLOCK (DK8-EP)
+/ BUFFERED DIGITAL I/O (DR8-EA)
+/ POINT-PLOT DISPLAY CONTROL (VC8-E)
+/
+/ MAIN DIFFERENCES TO LAB-8:
+/ * CLOCK IS PROGRAMMABLE. INTERRUPT-RATE HAS TO BE TO PROGRAMMED
+/ TO 10KC/S.
+/ * DIGITAL I/O HAS 12BIT INPUT.
+/ * POINT-PLOT DISPLAY HAS 10BIT RESOLUTION, BUT CANNOT INTENSIFY.
+/ ALSO INTENSITY-PULSE (DIXY) DOESN'T WORK SATISFACTORING.
+/ SO I ADDED STARS IN THE SKY, TO EMPLOY THE ELECTRON-BEAM WHILE
+/ WAITING FOR NEXT INTERRUPT.
+/ STARS COME FROM A STAR-MAP IN THE 20-VOL. "DTV-LEXIKON" FROM
+/ 1972. ISBN 3-423-03067-4. THE MAP IS IN VOL. 17 ON PAGE 283.
+/ I MADE A PHOTOCOPY FROM THIS BOOK IN SCALE 1:2 FOR BETTER
+/ ACCURACY. TO AVOID NEGATIVE COORDINATES, I LAID 0:0 IN THE
+/ LOWER LEFT CORNER OF THE MAP.
+/
+/ I ALSO ADDED A SCORE COUNTER.
+/
+/
+/
+/ EVAN SUITS
+/
+/ THIS VERSION WORKS OFF EITHER THE BLUE RIBBON CONNECTOR OR THE
+/ SR. WHEN THE PROGRAM IS STARTED (AT 0200) OR RESTARTED THE
+/ SR WILL BE TESTED AND IF =0000 WILL BE USED FOR THE COMMAND
+/ INPUT. OTHERWISE, THE BLUE RIBBON CONNECTOR (AX08 * C0-C7 *
+/ XR OPTION ONLY) CONTINGENCY INPUTS WILL BE USED.
+/
+/ WHEN THE PROGRAM IS STARTED THE TWO SHIPS SHOULD
+/ APPEAR ON THE SCREEN WITH SHIP 'ONE' ON THE LEFT, SHIP
+/ 'TWO' ON THE RIGHT.
+/
+/ THE COMMAND WORD BIT ASSIGNMENTS ARE:
+/
+/ SR BIT: C: FUNCTION:
+/
+/ 0 0 SHIP ONE ROTATES LEFT
+/
+/ 1 1 SHIP ONE ROTATES RIGHT
+/
+/ 2 2 SHIP ONE ACCELERATES
+/
+/ 3 3 SHIP ONE FIRES
+/
+/
+/
+/ 8 4 SHIP TWO ROTATES LEFT
+/
+/ 9 5 SHIP TWO ROTATES RIGHT
+/
+/ 10 6 SHIP TWO ACCELERATES
+/
+/ 11 7 SHIP TWO FIRES
+/
+/
+/
+/ NOTE THAT TURNING RIGHT AND LEFT SIMULTANEOUSLY THROWS
+/ THE SHIP INTO HYPERSPACE. IN THE CURRENT VERSION THE ODDS
+/ ARE IN FAVOR OF YOUR MAKING IT BACK SAFELY. THE GAME IS OVER
+/ WHEN ONE OR BOTH OF THE SHIPS HAVE BEEN DESTROYED AND THE
+/ WINNER (IF ANY) IS IN NORMAL SPACE. WHEN THE WINNER
+/ HAS BEEN ANNOUNCED, HIT ANY TTY KEY TO RESTART.
+/
+
+\f
+
+/ SYMBOL DEFINITIONS FOR PAL8-PAL10
+
+DXC=6301 /CLEAR X REGISTER
+DYC=6311 /CLEAR Y REGISTER
+DYL=6312 /LOAD Y FROM AC
+DXL=6302 /LOAD X FROM AC
+DIS=6304 /INTENSIFY POINT
+SKXK=6321 /SKIP ON CRYSTAL CLK FLAG
+DSB=6324 /SET BRIGHTNESS (BRIGHT)
+XRIN=6331 /OR EXTERNAL SENSE REGISTER IN AC
+XRCL=6334 /SET BITS IN AC CLEAR CORRESP. BITS IN SENSE REG.
+ZTEN=6342 /ZEROS IN AC CLEAR BITS IN ENABLE REGISTER
+OTEN=6344 /ONES IN AC SET BIS IN ENABLE REG. THEN CLA
+CLXK=6352 /CLEAR CRYSTAL CLK FLAG
+CRF=6072 /CLEAR SOME UNKNOWN FLAGS
+CCF=6052 /CLEAR SOME UNKNOWN FLAGS
+
+CLZE=6130 /CLEAR CLOCK ENA REG. PER 1 IN AC
+CLSK=6131 /SKIP ON CLOCK FLAG
+CLOE=6132 /SET CLOCK REG PER 1 IN AC
+CLAB=6133 /AC TO CLOCK COUNTER
+CLSA=6135 /STATUS TO AC, CLEAR CLK FLAG
+
+DISD=6052 /SKIP ON DONE
+DILX=6053 /LOAD X REGISTER
+DILY=6054 /LOAD Y REGISTER
+DIXY=6055 /CLEAR DONE AND INTENSIFY
+
+DBRI=6514 /LOAD CONTENT OF INPUT REGISTER TO AC
+\f/
+/ THIS PROGRAM RELIES ON THE PROGRAM INTERUPT FACILITY FOR
+/ REAL WORLD TIMING PURPOSES.
+/
+
+ *0
+
+ 0 /EFFECTIVE JMS 0 ON PROGRAM INTERUPT
+ JMP I 2 /EXIT IMMEDIATLY TO SERVICE ROUTINE
+ INTSER
+
+EMPTY, 0 /THESE LOCATIONS ARE RESERVED FOR
+ODT1, 0 /DEBUGGERS, ETC.
+ODT2, 0
+ODT3, 0
+
+/
+/ ALL THE AUTO INDEX REGISTERS ARE NAMED BUT NOT ALL OF
+/ THEM ARE USED. THE STATUS OF ANY GIVEN REGISTER CANNOT
+/ BE DETERMINED AT ANY TIME EXCEPT BY CAREFUL INSPECTION OF
+/ THE CODE.
+/
+
+ *10
+
+AUTO10, 0
+AUTO11, 0
+AUTO12, 0
+AUTO13, 0
+AUTO14, 0
+AUTO15, 0
+AUTO16, 0
+AUTO17, 0
+
+/
+/ THE FOLLOWING ARE THE DATA FILES FOR THE TWO SPACE SHIPS
+/ AS WELL AS CERTAIN OTHER PARAMETERS FOR CALCULATING POSITIONS
+/ AND SO ON. THE ORDER OF THE LOCATIONS MUST BE PRESERVED
+/ ALTHOUGH THE SIZE OF THE TABLES MAY BE VARIED
+/
+
+ *20
+
+ONEOUT, 0 /IF NON-ZERO CONTAINS REAMINING TIME OF EXPLOSION
+ONECNT, 0 /NUMBER OF POINTS IN FIGURE TO BE DISPLAYED
+ONEFLG, 0 /IN OR OUT OF NORMAL SPACE
+ONETHE, 0 /ANGLE OF ORIENTATION ON SCREEN
+ONEVEX, 0 /X COMPONENT OF VELOCITY
+ONEVEY, 0 /Y COMPONENT OF VELOCITY
+ONEPEX, 0 /X POSITION (12 BITS)
+ONEPEY, 0 /Y POSITION (12 BITS)
+ONESIN, 0 /SINE OF ANGLE
+ONECOS, 0 /COSINE OF ANGLE
+ONEFIN, 0 /SET WHEN EXPLOSION DIES OUT
+
+TWOOUT, 0 /SAME CONTENT AND ORDER
+TWOCNT, 0 /AS ABOVE
+TWOFLG, 0
+TWOTHE, 0
+TWOVEX, 0
+TWOVEY, 0
+TWOPEX, 0
+TWOPEY, 0
+TWOSIN, 0
+TWOCOS, 0
+TWOFIN, 0
+
+LASTX, 0 /KKKK
+LASTY, 0
+LASTX1, 0
+LASTY1, 0
+/
+/ THESE LOCATIONS ARE USED BY THE "VECTOR GENERATOR" IN
+/ DISPLAYING THE FIGURES. A FOUR DOT VECTOR WILL BE DRAWN
+/ FROM XONE,YONE TO XTWO,YTWO WITH STEPS OF SIZE DIXTEM,DIYTEM
+/
+
+XONEDS, 0
+YONEDS, 0
+XTWODS, 0
+YTWODS, 0
+DIXTEM, 0
+DIYTEM, 0
+DISCNT, 0
+PNTCNT, 1
+
+/
+/ THE NEXT LOCATIONS ARE USED BY CALPOS TO DO A FAST
+/ MULTIPLY TO HELP CALCULATE THE DISPLAY FILES.
+/
+T10SIN, 0
+T20SIN, 0
+T30SIN, 0
+T10COS, 0
+T20COS, 0
+T30COS, 0
+
+CALSIN, 0
+CALCOS, 0
+
+\f
+/
+/ NOW COME THE VARIOUS ODDS AND ENDS ONE USUALLY FINDS ON
+/ PAGE ZERO
+/
+
+SINE, SINEIN
+COSINE, COSINI
+MULT, MULTI
+RSHIFT, SHIFTR
+VECTOR, DISPLY
+CALPOS, POSCAL
+INTWRD, 0
+INTCNT, 0
+CLOCK, 0
+HYPER, HYPSET
+MESOUT, CHARS
+THEADJ, THEAJI
+VEESCL, VEELIM
+ISHFT, DISHFT
+RESET1, RESE1
+GAMOVR, -3
+ACCFLG, 0
+ACCPER, -30
+MEXP, -400
+
+PROX, 0
+PROY, 0
+PROLIF, -360
+BUFTMP, 0
+ONEFIL, DISBUF
+TWOFIL, DISBUF+40
+
+P5, 5
+P10, 10
+P17, 17
+P20, 20
+P37, 37
+P40, 40
+P65, 65
+P100, 100
+P6601, 6601
+P132, 132
+P200, 200
+P400, 400
+P550, 550
+P600, 600
+P3777, 3777
+
+M3, -3
+M4, -4
+M6, -6
+M10, -10
+M11, -11
+M264, -264
+M100, -100
+M200, -200
+M400, -400
+M550, -550
+M600, -600
+M1000, -1000
+M7605, 7605
+SB, 0
+SBI, STARS
+MESS, 0
+IDLE, NOP / HLT
+ DBRI
+ TAD M0021
+ SNA CLA
+ JMP I RESTR
+ JMP I BACK
+BACK, JOBLOP+1
+M0021, -0021
+RESTR, RESTRT\f
+/
+/ THE PROGRAM MAY BE STARTED OR RESTARTED AT ANYTIME AT 0200.
+/ THE DATA FILE ON PAGE ZERO IS CLEARED, ALL FLAGS INITIALIZED,
+/ AND THE SR EXAMINED. IF THE SR=0 THE DISPLAY UPDATE ROUTINES
+/ ARE SET TO PICK UP THE STATUS WORD FROM THE SR. IF THE SR
+/ DOES NOT EQUAL ZERO, THE STATUS WORD IS READ FROM THE EIGHT
+/ CONTINGENCY INPUTS ON THE BLUE RIBBON CONNECTOR OF THE AX08
+/ (XR OPTION ONLY). JUMP IS THEN TO THE DISPLAY
+/ FILE UPDATE TO START OFF THE GAME.
+/
+
+ *200
+
+START, CLA CLL /START OR RESTART HERE ANY OLD TIME
+ LAS /SR
+ SNA CLA
+ TAD SWRD /USE THE SR
+ TAD XROPT /USE THE BLUE RIBBON CONNECTOR
+ DCA COLDST /AND LEAVE IN THE TRAP LOCATION
+
+RESTRT, CLA CMA
+/ XRCL / ORG
+ CLZE / KKKK
+ CLAB
+ CLA CLL
+
+ TAD P17 /FIRST CLEAR THE POSITION AND DATA
+ DCA AUTO10 /TABLES OF THE TWO SHIPS
+ TAD TABLEN
+ DCA AUTO11
+ DCA I AUTO10
+ ISZ AUTO11
+ JMP .-2
+
+ TAD STRT1 /SET THE STARTING POSITIONS OF THE
+ DCA ONEPEX /TWO SHIPS
+ TAD STRT2
+ DCA TWOPEX
+ TAD P37 /SET TRIG FUNCTIONS JUST IN CASE
+ DCA ONECOS
+ TAD P37
+ DCA TWOCOS /ZERO DEGREES IS POINTING STRAIGHT UP
+ IAC
+ DCA PNTCNT
+ TAD ACCPER /SET COUNT FOR VELOCITY INCREASE
+ DCA ACCFLG
+ DCA ONEFIN /CLEAR ALL GAME END FLAGS
+ DCA TWOFIN
+ DCA GAMOVR
+ JMS I BUFSET /RESET ALL PROJECTILE DISPLAY BUFFERS
+ / ZTEN /ORG
+ / OTEN
+ / RRB
+ / CRF /UNKNOWN FLAG
+ / CCF /UNKNOWN FLAG
+ TAD P5410 /START UP THE CRYSTAL CLOCK IN THE AX08
+ CLOE /KK
+ TCF /CLEAR OTHER REMAINING LIKELY FLAGS
+ KCF
+ CLA
+ JMP COLDST /AND GO TO IT
+P5410, 5410
+\f
+/
+/ UPDATE IS REACHED WHENEVER THE PROGRAM IS STARTED OR THE
+/ CLOCK COUNT OVERFLOWS INDICATING TIME TO RECALCULATE THE
+/ THE DISPLAY FILES AND REFRESH THE DISPLAY. THE INTERUPT
+/ COUNT IS RESTORED, THE STATUS WORD IS PICKED UP FROM EITHER
+/ THE SR OR BRC, AND THE RECALCULATION PROCESS BEGUN.
+/
+
+UPDATE, CLA CLL /HERE ON CLOCK COUNT OVERFLOW.
+ /START NEXT SWEEP
+COLDST, 0 /TRAP TO READ SR OR BRC
+ LAS /HERE FOR SR
+/ SWITCHES FOR SHIP 1 AND 2 WERE WRONG! KKK
+ DCA INTWRD /STORE TEMPORARILY
+ TAD INTWRD
+ JMS CLRV
+ TAD INTWRD /MASK OUT LEFTMOST 4 BITS
+ RTR /FOR NUMBER ONE
+ BSW
+ AND RYTHAF
+ DCA INTTEM /AND STORE
+ TAD INTWRD /MASK OUT RIGHTMOST BITS FOR NUMBER TWO
+ BSW
+ RTR
+ AND LFTHAF
+ TAD INTTEM /ADD TOGETHER
+ JMP CODST1 /AND CONTINUE
+
+CODST,
+/ XRIN /HERE FOR BRC - PICK UP AND CLEAR
+/ XRCL
+ DBRI / KKKK
+ RAL
+ SNL
+ JMP CODST2
+ AND M0600
+ TAD P0600
+CODST2, SMA
+ JMP CODST3
+ AND M0030
+ TAD P0030
+CODST3, RAR
+CODST1, DCA INTWRD /CONTINUE
+ TAD M550 /RESTORE INTERUPT COUNT BEFORE NEXT
+ DCA INTCNT /UPDATE
+ ION /GET READY FOR THE NEXT CYCLE
+ TAD ACCFLG /ALLOW VELOCITY INCREASE THIS TIME?
+ IAC /ONLY WHEN ACCFLG=0
+ SMA SZA
+ TAD ACCPER /IF ZERO, RESET COUNT
+ DCA ACCFLG
+
+ JMP I .+1 /NOW GET DOWN TO WORK.
+ ONEUP
+
+BUFSET, SETBUF
+TABLEN, AUTO17-CALCOS
+INTTEM, 0
+LFTHAF, 0360
+RYTHAF, 0017
+M0600, 7177
+P0600, 0600
+M0030, 7747
+P0030, 0030
+STRT1, 1000
+STRT2, -1000
+SWRD, 2000-CODST
+XROPT, JMP CODST
+
+\f
+/
+/ THIS IS THE INTERUPT SERVICE ROUTINE. MOST OF THE
+/ INTERUPTS WILL BE FROM THE CRYSTAL CLOCK WHICH WILL BE
+/ COUNTED AND UNLESS THE COUNT OVERFLOWS THE INTERUPT IS
+/ DISMISSED IMMEDIATLY. IF THE COUNT OVER FLOWS, JMP IS TO
+/ UPDATE WITH IOF.
+/
+/ SPECIAL CASE IS KEYBOARD INTERUPT WHEN THE GAMOVR FLAG IS
+/ SET IN WHICH CASE THE GAME IS RESTARTED.
+/
+/ UNEXPECTED INTERUPTS ARE COUNTED AND AFTER ENOUGH OF THEM
+/ HAPPEN THE PROGRAM HALTS. IF THIS HAPPENS RELOAD OR FIND THE
+/ STRANGE FLAG
+/
+
+INTSER, DCA INTACC /HERE RIGHT AFTER INTERUPT - STORE
+ RAR /AC AND LINK
+ DCA INTLNK /FOR POSSIBLE CONTINUATION
+/ SKXK /WAS IT THE CRYSTAL CLOCK?
+ CLSK /KKKK
+ JMP INTBUS /NO TRY SOMETHING ELSE
+/ CLXK /YES CLEAR THE FLAG
+ CLSA
+ ISZ CLOCK /AND BUMP CLOCK COUNTER
+ NOP /IGNORE OVERFLOW
+ ISZ INTCNT /TIME FOR AN UPDATE?
+ JMP INTRET /NO, DISMISS THE INTERUPT
+ JMP UPDATE /YES, GO TO IT
+
+INTBUS, KSF /HERE ON NON-CLOCK INTERUPT
+ JMP .+5 /NOT THE KEYBOARD
+ KRB /READ KEYBOARD
+ TAD M3 /CTRL-C ?
+ SNA CLA
+ JMP OS8
+ TAD GAMOVR /IS THE GAMEOVER
+ SZA CLA
+ JMP RESTRT /YES, RESTART
+ TCF /NO, HELL WITH IT
+ ISZ INTGLH /COUNT ONE BADDIE
+ SKP
+ HLT /HALT IF TOO MANY BADDIES
+
+INTRET, CLA CLL /HERE TO DISMISS THE INTERUPT
+ TAD INTLNK
+ RAL
+ TAD INTACC
+ ION
+ JMP I 0
+/
+OS8, IOF
+ JMP I M7605
+/
+INTACC, 0
+INTLNK, 0
+INTGLH, 0
+
+\f
+/
+/ NOW BEGINS THE GREAT UPDATE PROCEEDURE, FIRST FOR SHIP
+/ NUMBER ONE (THE DELTA SHAPED SHIP WHICH APPEARS ON
+/ THE LEFT AT THE START OF THE GAME). IF ALIVE THE STATUS
+/ WORD (INTWRD) IS TESTED FOR REQUESTS FOR LEFT TURN,
+/ RIGHT TURN, THRUST ON, AND LAUNCH PROJECTILE. THESE ACTIONS
+/ MAY OR MAY NOT BE ACTED UPON DEPENDING ON COUNTS AND FLAGS.
+/ WHEN THIS IS COMPLETE THE SAME OPERATION IS PERFORMED FOR
+/ NUMBER TWO.
+/
+ *400
+
+ONEUP, TAD ONEFLG /FIRST SEE IF IT'S IN NORMAL SPACE
+ SNA
+ JMP ONEOK /YES IT IS
+ IAC /NO, BUT IS IT JUST COMING OUT?
+ SNA
+ TAD ONEFIN /YES, THROW BACK IN IF ALREADY DESTROYED
+ DCA ONEFLG /OTHERWISE JUST COUNT ONE
+ JMP I ITWOUP /AND GO TO FIX UP NUMBER TWO
+
+ONEOK, TAD ONEOUT /IN NORMAL SPACE - IS IT EXPLODING?
+ SZA CLA
+ JMP ONEFIG /IF YES, ALLOW NO CONTROLS
+ TAD TWOFIN /HAS THE ENEMY BEEN VANQUISHED?
+ SZA CLA
+ JMS I ONEWN /YES, SIGNAL VICTORY
+ TAD INTWRD /NOW BEGIN TEST OF REQUEST
+ AND OP300 /LEFT AND RIGHT TURN TOGETHER MEAN HYPERSPACE!
+ TAD OM300 /TEST BITS 4 AND 5
+ SZA CLA
+ JMP ONELEF /NOPE, CONTINUE
+ CMA /YES, CALL HYPER WITH AC=-1 FOR NUMBER ONE
+ JMP I HYPER
+ONELEF, TAD INTWRD /REQUEST FOR LEFT TURN?
+ AND P200 /TEST BIT 4
+ SNA CLA
+ JMP ONERYT /NO
+ CLA CLL CMA /YES DECREMENT ANGLE
+ JMP ONEFIG
+
+ONERYT, TAD INTWRD /HOW ABOUT RIGHT TURN
+ AND P100 /TEST BIT 5
+ SZA CLA
+ IAC /YES, INCREMENT ANGLE
+
+ONEFIG, TAD ONETHE /PICK UP AND ADJUST ANGLE (MAYBE)
+ JMS I THEADJ /BRING BACK WITHIN LIMITS OF TRIG FUNCTIONS
+ DCA ONETHE /AND STORE
+ TAD ONETHE /FIND THEM TRIG FUNCTIONS
+ JMS I SINE /AND STORE ONCE AND FOR ALL
+ DCA ONESIN /IN THE APPROPRIATE PLACES
+ TAD ONETHE
+ JMS I COSINE
+ DCA ONECOS
+ TAD ONEOUT /DO NOT ALLOW THRUST IF EXPLODING
+ SZA CLA
+ JMP ONEVEL
+
+\f
+
+ONEMOV, TAD ACCFLG /ALLOW ANY VELOCITY INCREASE THIS CYCLE?
+ SZA CLA
+ JMP ONEVEL /NOPE
+ TAD INTWRD /YES, ANY REQUESTED?
+ AND P40 /TEST BIT 6
+ SNA CLA
+ JMP ONEVEL /NONE REQUESTED
+ TAD ONECOS /YES, ADD IN VELOCITY INCREMENT DEPENDING
+ TAD ONEVEY /ON ORIENTATION
+ JMS I VEESCL /BUT DO NOT ALLOW TO EXCEED MAXIMUM
+ DCA ONEVEY /AND STORE
+ TAD ONESIN /DO THE SAME FOR THE OTHER (X) COMPONENT
+ TAD ONEVEX
+ JMS I VEESCL
+ DCA ONEVEX
+
+
+
+ONEVEL, TAD ONEVEX /NOW UPDATE THE POSITION WITH THE
+ JMS I ISHFT /VELOCITY COMPONENTS DIVIDED BY 4
+ JMS I ISHFT /THIS MAINTAINS MAXIMUM RESOLUTION
+ TAD ONEPEX
+ DCA ONEPEX /IGNORE ANY OVERFLOW
+ TAD ONEVEY /DO THE SAME FOR Y COORDINATE
+ JMS I ISHFT /AND VELOCITY COMPONENT
+ JMS I ISHFT
+ TAD ONEPEY
+ DCA ONEPEY
+ TAD ONEOUT /DO NOT ALLOW PROJECTILE LAUNCH IF
+ SZA CLA /EXPLODING
+ JMP I ITWOUP
+
+\f
+
+ONELNC, TAD LNC1FG /OTHERWISE, SEE IF RELOAD IS FINISHED
+ SNA CLA
+ JMP .+3
+ ISZ LNC1FG /NO, CONTINUE RELOADING
+ JMP I ITWOUP /AND EXIT
+ TAD INTWRD /YES, READY TO LAUNCH, TRIGGER BEEN PULLED?
+ AND P20 /TEST BIT7
+ SNA CLA
+ JMP I ITWOUP /NO, WAIT FOR A BETTER SHOT
+ /.....I GUESS.....
+ TAD PROLIF /YES, SET CYCLE COUNT FOR THIS LAUNCH
+ DCA I AUTO16 /AUTO16 ALWAYS POINTS AT THE NEXT SLOT IN THE FILE
+ TAD ONEVEX /ADD SHIPS VELOCITY (SCALED OF COURSE)
+ JMS I ISHFT /TO ORIENTATION TO EXTABLISH X VELOCITY
+ JMS I RSHIFT /COMPONENT OF PROJECTILE
+ TAD ONESIN
+ JMS I RSHIFT /AND STICK IT IN THE FILE
+ DCA I AUTO16
+ TAD ONESIN /MOVE THE LAUNCH POINT OUTSIDE THE
+ CLL RTL /SHIP OF ORIGIN
+ TAD ONEPEX
+ DCA I AUTO16 /AND STORE X POSITION
+ TAD ONEVEY /NOW DO THE SAME FOR THE Y VELOCITY AND
+ JMS I ISHFT /POSITION
+ JMS I RSHIFT
+ TAD ONECOS
+ JMS I RSHIFT
+ DCA I AUTO16
+ TAD ONECOS
+ CLL RTL
+ TAD ONEPEY
+ DCA I AUTO16
+ TAD M200 /START RELOAD CYCLE
+ DCA LNC1FG
+ JMS I RESET1 /RESET AUTO16 TO NEXT HOLE
+
+ JMP I .+1 /NOW TO FIX IT UP WITH NUMBER TWO
+ITWOUP, TWOUP
+
+LNC1FG, 0 /PROJECTILE LAUNCH ENABLE
+
+OP300, 300 /HYPERSPACE REQUEST CODE BITS 4 AND 5
+OM300, -300
+ONEWN, ONEWIN /POINTER TO VICTORY MESSAGE
+
+\f
+/
+/ HERE BEGINS THE UPDATE PROCEEDURE FOR SHIP NUMBER TWO.
+/ OPERATION IS THE SAME AS FOR NUMBER ONE ABOVE.
+/
+CLRV, 0
+ BSW
+ SMA CLA
+ JMP I CLRV
+ DCA ONEVEX
+ DCA ONEVEY
+ DCA TWOVEX
+ DCA TWOVEY
+ JMP I CLRV
+ *600
+
+TWOUP, TAD TWOFLG /FIRST SEE IF IT'S IN NORMAL SPACE
+ SNA
+ JMP TWOOK /YES, CONTINUE
+ IAC /NO, BUMP COUNT AND TEST FOR REENTRY
+ SNA
+ TAD TWOFIN /IF RE-ENTERING THROW BACK OUT IF FINISHED
+ DCA TWOFLG /AND CONTINUE
+ JMP I IONEST
+
+TWOOK, TAD TWOOUT /HERE WHEN READY TO UPDATE IN NORMAL SPACE
+ SZA CLA /IS IT EXPLODING?
+ JMP TWOFIG /YES DO NOT ALLOW HYPERSPACE
+ TAD ONEFIN /DID WE JUST WIN?
+ SZA CLA
+ JMS I TWOWN /YES ENABLE END OF GAME MESSAGE
+ TAD INTWRD /TEST FOR HYPERSPACE REQUEST
+ AND OP14
+ TAD OM14 /BITS 8 AND 9 MUST BE SET
+ SNA CLA
+ JMP I HYPER /8 AND 9 SET. ENTER HYPER ROUTINE WITH AC=0
+ /FOR SHIP NUMBER 2
+TWOLEF, TAD INTWRD /TEST FOR LEFT TURN - BIT 8
+ AND P10
+ SNA CLA
+ JMP TWORYT /NOT SET
+ CLA CLL CMA /SET, DECREMENT TWOTHE BY 1 DEGREE
+ JMP TWOFIG /SKIP TEST FOR RIGHT TURN
+
+TWORYT, CLA CLL IAC RTL /TEST FOR RIGHT TURN - BIT 9
+ AND INTWRD
+ SZA CLA
+ IAC /IF SET INCREMENT TWOTHE BY 1 DEGREE
+
+TWOFIG, TAD TWOTHE /UPDTAE TWOTHE
+ JMS I THEADJ /BRING TO WITHIN LIMITS OF SINE,COSINE
+ DCA TWOTHE /AND STORE
+ TAD TWOTHE
+ JMS I SINE /CALCULATE SINE AND COSINE FUNCTIONS
+ DCA TWOSIN /AND STORE IN DATA TABLE
+ TAD TWOTHE
+ JMS I COSINE
+ DCA TWOCOS
+ TAD TWOOUT /DO NOT ALLOW VELOCITY CHANGE IF EXPLODING
+ SZA CLA
+ JMP TWOVEL
+
+\f
+
+TWOMOV, TAD ACCFLG /NOW FOR ACCELERATION. TEST TO SEE IF ALLOWED
+ SZA CLA /DURING THIS UPDATE CYCLE
+ JMP TWOVEL /NOPE
+ CLL IAC RAL /YES, TEST FOR BIT 2 SET
+ AND INTWRD
+ SNA CLA
+ JMP TWOVEL /NOT SET
+
+ TAD TWOSIN /UPDATE X VELOCITY COMPONENT BY SINE OF
+ TAD TWOVEX /ANGLE OF ORIENTATION
+ JMS I VEESCL /AND SCALE TO NOT EXCEED MAX
+ DCA TWOVEX /UPDATE Y COMPONENT WITH COSINE
+
+ TAD TWOCOS
+ TAD TWOVEY
+ JMS I VEESCL
+ DCA TWOVEY
+
+
+
+TWOVEL, TAD TWOVEX /NOW UPDATE THE POSITION WITH THE VELOCITY
+ JMS I ISHFT /COMPONENTS/16
+ JMS I ISHFT
+ TAD TWOPEX
+ DCA TWOPEX
+ TAD TWOVEY
+ JMS I ISHFT
+ JMS I ISHFT
+ TAD TWOPEY
+ DCA TWOPEY
+ TAD TWOOUT
+ SZA CLA
+ JMP I IONEST
+
+\f
+
+TWOLNC, TAD LNC2FG /NOW CHECK FOR PROJECTILE LAUNCH. FIRST
+ SNA CLA /TEST TO SEE IF RELOAD COMPLETE
+ JMP .+3
+ ISZ LNC2FG /NO, COUNT ONE CYCLE AND EXIT
+ JMP I IONEST
+ IAC /YES, TEST TRIGGER BIT 11
+ AND INTWRD
+ SNA CLA
+ JMP I IONEST /NOT SET, HELL WITH IT
+
+ TAD PROLIF /OK, SET PROJECTILE LIFE
+ DCA I AUTO16 /AUTO16 IS ALWAYS POINTING AT THE NEXT SLOT
+ TAD TWOVEX /ADD SHIPS VELOCITY
+ JMS I ISHFT /(ADJUSTED)
+ JMS I RSHIFT
+ TAD TWOSIN /TO THAT OF PROJECTILE - AGAIN X COMPONENT
+ JMS I RSHIFT /FROM SINE OF ANGLE OF ORIENTATION
+ DCA I AUTO16
+ TAD TWOSIN /SET INITIAL POSITION TO BE JUST AHEAD
+ CLL RTL /OF THE SHIP
+ TAD TWOPEX /X COMPONENT
+ DCA I AUTO16
+ TAD TWOVEY /NOW THE Y COMPONENTS FROM Y VELOCITY
+ JMS I ISHFT /Y POSITION AND COSINE
+ JMS I RSHIFT
+ TAD TWOCOS
+ JMS I RSHIFT
+ DCA I AUTO16
+ TAD TWOCOS
+ CLL RTL
+ TAD TWOPEY
+ DCA I AUTO16
+ TAD M200
+ DCA LNC2FG /200 CYCLES OF RELOAD
+ JMS I RESET1 /DRINK LEADEN DEATH, NUMBER ONE!
+
+ JMP I .+1 /FINAL EXIT TO DISPLAY FILE CALCULATIONS
+IONEST, ONESET
+
+LNC2FG, 0 /RELOAD COUNT
+
+OP14, 14 /HYPERSPACE CODE
+OM14, -14
+TWOWN, TWOWIN
+
+\f
+/
+/ HERE BEGINS THE DISPLAY CALCULATIONS FOR THE TWO SHIPS. AT
+/ THIS POINT ONLY THE POSITION AND ORIENTATION OF EACH VESSEL
+/ IS ONF INTEREST SINCE THE VELOCITY AND ALL THAT HAVE ALREADY
+/ BEEN TAKEN CARE OF. FOR THE BOTH SHIPS THE DISPLAY FILES ARE
+/ CALCULATED AS A SERIES OF PAIRS OF X,Y COORDINATES. BETWEEN
+/ EACH PAIR OF POINTS A FOUR POINT VECTOR WILL BE DRAWN. THE
+/ ACTUAL COORDINATES ARE CALCULATED AS DISPLACEMENTS
+/ FROM THE CENTRAL PSOTION OF THE SHIP, TAKING INTO ACCOUNT THE
+/ ANGLE OF ORIENTATION. THE FORMULAS FOLLOWED ARE:
+/
+/ X(POINT)=X(BASE)+X(REL)*COS[THE]+Y(REL)*SINE[THE]
+/
+/ Y(POINT)=Y(BASE)+Y(REL)*COS[THE]-X(REL)*SINE[THE]
+/
+/ WHERE SINE[THE] AND COS[THE] ARE THE FUNCTIONS OF THE
+/ ANGLE OF ORIENTATION, X(BASE) AND Y(BASE) ARE THE
+/ COORDINATES OF THE SHIPS POSITION AND X(REL) AND Y(REL)
+/ CORRESPOND TO DISPLACEMENT PAIRS DEPENDING ON THE SHAPE
+/ OF THE FIGURE. ALL X AND Y RELS LIE WITHIN THE RANGE 0-3 AND
+/ THERE FORE ALL NECESSARY DISPLACEMENTS FROM BASE COORDINATES
+/ MAY BE CALCULATEDFROM DIFFERENT COMBINATIONS OF T10SIN, T20COS
+/ ETC. THESE VALUES ARE CALCULATED BY A CALL TO POSCAL WITH THE SINE
+/ AND COSINE OF THE ANGLE OF INTEREST IN CALSIN AND CALCOS.
+/
+/ FOLLOWING THIS METHOD ANY FIGURE DESCRIBABLE WITH A 7 BY 7
+/ MATRIX OF POINTS MAY BE QUICKLY CALCULATED.
+/
+/ BEGINNING AT ONESET DIFFERENT DISPLACEMENT PAIRS ARE CALCULATED
+/ AND DEPOSITIED THROUGH AUTO10 TO FORM THE DISPLAY FILE FOR SHIP NUMBER ONE.
+/
+
+
+ *1000
+
+ONESET, CLA CLL /BEGIN DISPLAY FILE FOR NUMBER ONE
+ TAD ONEFLG /DONT BOTHER IF NOT IN NORMAL SPACE
+ SZA CLA
+ JMP I ITWOST
+ TAD ONESIN /SET UP FOR MATRIX COMPONENT CALCULATIONS
+ DCA CALSIN
+ TAD ONECOS
+ DCA CALCOS
+ JMS I CALPOS /CALL THE CALCULATOR
+
+/
+/ CONSIDER THE 7 BY 7 MATRIX OF DISPLACEMENT POINTS WITH THE
+/ CENTER AT 0,0 CORRESPONDING TO THE SHIPS POSITION. A SERIES
+/ OF POINTS IS NOW DESCRIBED AROUND THIS CENTER USING THE
+/ MULTIPLES OF THE TRIG FUNCTIONS JUST CALCULATED
+/ SO THAT ANY POINT ON THE OUTLINE IS DESCRIBABLE AS X,Y
+/ DISPLACED BY X,Y OF THE SHIP ITSELF
+/
+
+ TAD ONEFIL /SET UP AUTO10 AS THE DISPLAY FILE
+ DCA AUTO10 /POINTER
+ TAD ONEPEX /THE FIRST POINT OF THE OUTLINE IS
+ TAD T30SIN
+ DCA I AUTO10 / 0,3 OR TOP CENTER
+ TAD ONEPEY
+ TAD T30COS
+ DCA I AUTO10
+
+ TAD T10COS
+ CIA /THE SECOND IS
+ TAD ONEPEX
+ DCA I AUTO10 / -1,0
+ TAD T10SIN /OR JUST LEFT OF DEAD CENTER
+ TAD ONEPEY /AND SO ON
+ DCA I AUTO10
+
+ TAD T30SIN
+ TAD T30COS /THE THIRD POINT IS
+ CIA
+ TAD ONEPEX / -3,-3
+ DCA I AUTO10
+ TAD T30COS /OR BOTTOM LEFT HAND CORNER
+ CIA
+ TAD T30SIN
+ TAD ONEPEY
+ DCA I AUTO10
+
+\f
+
+ TAD T10SIN
+ CIA /FOURTH POINT
+ TAD ONEPEX
+ DCA I AUTO10 / 0,-1
+ TAD T10COS
+ CIA /OR JUST BELOW CENTER
+ TAD ONEPEY
+ DCA I AUTO10
+
+FLAM1, TAD INTWRD /TEST FOR POWER ON. IF ON, DRAW THE
+ AND P40 /FLAME WITH AN EXTRA POINT SOME
+ SNA CLA /DISTANCE DIRECTLY BELOW THE SHIP
+ JMP ONECON /POWER NOT ON - CONTINUE
+ TAD ONEOUT /DO NOT ALLOW IF EXPLODING
+ SZA CLA
+ JMP ONECON
+
+ TAD ONFG1 /USE ONFG1 TO TURN THE FLAME ON AND
+ SNA /OFF TO MAKE IT FLICKER. DISPLAY THE
+ CLA CLL CMA RAL /FLAME ONE TIME OUT OF THREE
+ DCA ONFG1
+
+ ISZ ONFG1
+ JMP ONECON /ONE OUT OF THREE TIMES THIS WILL SKIP
+
+ TAD ONFG2 /VARY ALSO THE LENGHT OF THE FLAME
+ CMA /WITH LONG SHORT LONG SHORT
+ DCA ONFG2
+
+ TAD ONFG2 /TIP OF FLAME AT EITHER
+ SNA CLA
+ TAD T10SIN / 0,-4 OR
+ TAD T30SIN / 0,-3
+ CIA
+ TAD ONEPEX
+ DCA I AUTO10
+ TAD ONFG2
+ SNA CLA
+ TAD T10COS
+ TAD T30COS
+ CIA
+ TAD ONEPEY
+ DCA I AUTO10
+
+ TAD T10SIN
+ CIA
+ TAD ONEPEX /RETURN DISPLAY TO 0,-1
+ DCA I AUTO10
+ TAD T10COS
+ CIA
+ TAD ONEPEY
+ DCA I AUTO10
+ CLA CLL CMA RAL /ADD -2 TO POINT COUNT
+
+\f
+
+ONECON, TAD M6 /SET POINT COUNT TO -6 OR -8
+ DCA ONECNT
+
+ TAD T30SIN /CONTINUE WITH DISPLAY FILE - THIS POINT
+ CIA
+ TAD T30COS / AT 3,-3
+ TAD ONEPEX /
+ DCA I AUTO10 /OR LOWER RIGHT HAND CORNER
+ TAD T30SIN
+ TAD T30COS
+ CIA
+ TAD ONEPEY
+ DCA I AUTO10
+
+ TAD T10COS /NEXT
+ TAD ONEPEX /
+ DCA I AUTO10 / 1,0
+ TAD T10SIN /
+ CIA / OR JUST RIGHT OF CENTER
+ TAD ONEPEY
+ DCA I AUTO10
+
+ TAD T30SIN /FINALLY BACK TO
+ TAD ONEPEX /
+ DCA I AUTO10 / 0,3
+ TAD T30COS /
+ TAD ONEPEY / TOP CENTE
+ DCA I AUTO10
+
+ JMP I ITWOST /NOW FOR NUMBER TWO
+ITWOST, TWOSET
+
+ONFG1, 0 /USED TO COUNT FLICKERS
+ONFG2, 0 /SHORT OR LONG FLAG
+
+\f
+/
+/ HERE BEGINS THE DISPLAY FILE GENERATOR FOR SHIP TWO.
+/ IT WORKS JUST LIKE THE ONE FOR NUMBER ONE BUT WITH
+/ DIFFERENT DISPLACEMENT PAIRS AND TWO EXTRA POINTS
+/
+
+ *1200
+
+TWOSET, CLA CLL /DONT BOTHER IF NOT IN NORMAL SPACE
+ TAD TWOFLG
+ SZA CLA
+ JMP I IFILDS
+ TAD TWOSIN /SET UP TO HAVE DISPLACEMENT INCREMENTS
+ DCA CALSIN /CALCULATED
+ TAD TWOCOS
+ DCA CALCOS
+ JMS I CALPOS
+
+ TAD TWOFIL /SET AUTO10 TO POINT TO SECOND DISPLAY
+ DCA AUTO10 /FILE
+ TAD T30SIN /FIRST POINT AT
+ TAD TWOPEX /
+ DCA I AUTO10 / 0,3
+ TAD T30COS /
+ TAD TWOPEY / OR TOP CENTER
+ DCA I AUTO10
+
+ TAD T20COS
+ CIA
+ TAD T20SIN
+ TAD TWOPEX
+ DCA I AUTO10
+ TAD T20SIN
+ TAD T20COS /SECOND POINT
+ TAD TWOPEY / -2,2
+ DCA I AUTO10
+
+ TAD T20COS /THIRD POINT
+ CIA / -2,0
+ TAD TWOPEX
+ DCA I AUTO10
+ TAD T20SIN
+ TAD TWOPEY
+ DCA I AUTO10
+
+
+
+ TAD T20COS
+ TAD T30SIN
+ CIA
+ TAD TWOPEX /FOURTH POINT
+ DCA I AUTO10 / -2,-3
+ TAD T30COS
+ CIA
+ TAD T20SIN
+ TAD TWOPEY
+ DCA I AUTO10
+
+\f
+
+ TAD T20SIN
+ CIA /NEXT
+ TAD TWOPEX / 0,-2
+ DCA I AUTO10
+ TAD T20COS
+ CIA
+ TAD TWOPEY
+ DCA I AUTO10
+
+FLAM2, CLA CLL IAC RAL /NOW THE FLAME BIT. CHECK FOR POWER ON
+ AND INTWRD
+ SNA CLA
+ JMP TWOCON /NO, FORGET IT
+ TAD TWOOUT /NOT ALLOWED IF EXPLODING
+ SZA CLA
+ JMP TWOCON
+
+ TAD TWFG1 /SET THE 1-3 FLICKER AS WITH #1
+ SNA
+ CLA CLL CMA RAL
+ DCA TWFG1
+
+ ISZ TWFG1 /ALSO THE LENGHT VARIATION
+ JMP TWOCON
+
+ TAD TWFG2 /EVERY OTHER TIME LONG
+ CMA
+ DCA TWFG2
+ /FLAME TIP AT EITHER
+ TAD TWFG2 / 0,-3
+ SNA CLA /OR
+ TAD T20SIN / 0,-5
+ TAD T30SIN
+ CIA
+ TAD TWOPEX
+ DCA I AUTO10
+ TAD TWFG2
+ SNA CLA
+ TAD T20COS
+ TAD T30COS
+ CIA
+ TAD TWOPEY
+ DCA I AUTO10
+
+ TAD T20SIN /NOW BACK UP TO THE SHIP
+ CIA
+ TAD TWOPEX
+ DCA I AUTO10
+ TAD T20COS
+ CIA
+ TAD TWOPEY
+ DCA I AUTO10
+
+ CLA CLL CMA RAL /ADD -2 TO POINT COUNT
+
+\f
+
+TWOCON, TAD M10 /SET POINT COUNT TO -8 OR -10
+ DCA TWOCNT
+
+ TAD T30SIN /CONTINUE WITH DISPLAY FILE
+ CIA /NEXT POINT AT 2,-3
+ TAD T20COS
+ TAD TWOPEX
+ DCA I AUTO10
+ TAD T30COS
+ TAD T20SIN
+ CIA
+ TAD TWOPEY
+ DCA I AUTO10
+
+
+
+ TAD T20COS /NEXT POINT
+ TAD TWOPEX /
+ DCA I AUTO10 / 2,0
+ TAD T20SIN
+ CIA
+ TAD TWOPEY
+ DCA I AUTO10
+
+ TAD T20COS /AND THE NEXT AT
+ TAD T20SIN
+ TAD TWOPEX / 2,2
+ DCA I AUTO10
+ TAD T20SIN
+ CIA
+ TAD T20COS
+ TAD TWOPEY
+ DCA I AUTO10
+
+ TAD T30SIN
+ TAD TWOPEX
+ DCA I AUTO10
+ TAD T30COS /AND THE LAST AT
+ TAD TWOPEY /
+ DCA I AUTO10 / 0,3
+
+ JMP I IFILDS /NOW TO DISPLAY THE WHOLE MESS
+IFILDS, FILDIS
+
+TWFG1, 0 /FLIK THE FLAME
+TWFG2, 0 /LONG OR SHORT
+
+\f
+/
+/ HERE TO DISPLAY THE TWO SHIPS. CHECK FIRST FOR COLLISION
+/ AND THEN SET THE TWO PAIRS OF COORDENATES FOR THE END
+/ POINTS AND CALL THE "VECTOR GENERATOR" TO DRAW THE DOTS
+/ IN BETWEEN. WHEN THE COUNT OVERFLOWS DO THE SAME FOR
+/ NUMBER TWO. THEN EXIT TO DISPLAY ALL THE PROJECTILES.
+/
+
+ *1400
+
+FILDIS, CLA CLL /ALL SET TO GO
+ JMS I COLIDE /TEST FOR COLLISION FIRST
+/ DSB 1 /IF NO COLLISION
+ NOP /KKKK
+ TAD ONEFLG /SKIP NUMBER ONE IF NOT IN NORMAL
+ SZA CLA /SPACE
+ JMP TWODIS
+
+ TAD ONEFIL /SET UP POINTERS TO DISPLAY FILE
+ DCA AUTO10 /FOR NUMBER ONE
+ TAD ONECNT /ALONG WITH VECTOR COUNT
+ DCA AUTO11
+ TAD I AUTO10 /SET OUT THE FIRST POINT PAIR
+ DCA XONEDS
+ TAD I AUTO10
+ DCA YONEDS
+ TAD ONEOUT /NORMAL DISPLAY OR EXPLOSION?
+ SZA CLA
+ JMP I IONEEX /GO ELSE WHERE FOR EXPLOSION
+
+FILONE, TAD I AUTO10 /STEP TO NEXT PAIR OF POINTS
+ DCA XTWODS /SET X AND Y TO NEW POINT
+ TAD I AUTO10
+ DCA YTWODS
+ JMS I VECTOR /CALL THE DOT DRAWING MACHINE
+ TAD LASTX
+ DCA LASTX1
+ TAD LASTY
+ DCA LASTY1
+ ISZ AUTO11
+ SKP /COUNT
+ JMP TWODIS /DO NUMBER TWO ON OVERFLOW
+ TAD XTWODS /SWAP POINTS FOR NEXT PAIR
+ DCA XONEDS
+ TAD YTWODS /THE GENERATOR DRAWS FROM ONE
+ DCA YONEDS /TOWARDS TWO
+ JMP FILONE
+
+\f
+
+TWODIS, TAD TWOFLG /HERE TO DO NUMBER TWO
+ SZA CLA /BUT NOT IF IN HYPER SPACE
+ JMP I IPRODS
+
+ TAD TWOFIL /SET UP FILE POINTER AS IN ONE
+ DCA AUTO10
+ TAD TWOCNT /AND THE COUNT
+ DCA AUTO11
+ TAD I AUTO10 /I SUPPOSE THIS COULD BE A SUBROUTINE TOO
+ DCA XONEDS
+ TAD I AUTO10
+ DCA YONEDS
+ TAD TWOOUT /IS IT EXPLODING?
+ SZA CLA
+ JMP I ITWOEX /YES, HOW EXCITING
+
+TWDLOP, TAD I AUTO10 /NO HOW DULL, STICK IN NEXT PAIR OF
+ DCA XTWODS /POINTS
+ TAD I AUTO10
+ DCA YTWODS /AND CALL THE VECTOR SEQUENCE
+ JMS I VECTOR
+ ISZ AUTO11
+ JMP .+3
+
+ JMP I .+1 /WHEN COUNT OVERFLOWS GO ON TO
+IPRODS, PRODIS /DO THE PROJECTILE THING
+
+ TAD XTWODS /OTHERWISE SWAP ON TO THE NEXT PAIR
+ DCA XONEDS /OF POINTS
+ TAD YTWODS
+ DCA YONEDS
+ JMP TWDLOP
+
+COLIDE, COLLID
+IONEEX, ONEEXP
+ITWOEX, TWOEXP
+
+\f
+/
+/ THIS IS THE SO CALLED "VECTOR GENERATOR" WHICH DRAWS A
+/ SERIES OF DOTS FROM XONEDS,YONEDS TO XTWODS,YTWODS.
+/ THE COORDINATE COMPONENTS ARE DIVIDED INTO FOURTHS AND
+/ FOUR DOTS DRAWN ON THE SCOPE SCREEN. NOTE THAT NO DOT
+/ IS DRAWN AT XONEDS,YONEDS. THIS IS COMPENSATED FOR ELSEWHERE.
+/
+
+
+DISPLY, 0 /ENTER TO DRAW A FOUR POINT VECTOR
+ TAD XONEDS /FROM XONEDS,YONEDS
+ CIA /TO XTWODS,YTWODS
+ TAD XTWODS /DIVIDE COORDINATE DIFERENCES INTO
+ JMS DISHFT /FOURTHS
+ DCA DIXTEM /AND STORE INCREMENT
+ TAD YONEDS
+ CIA
+ TAD YTWODS
+ JMS DISHFT
+ DCA DIYTEM
+ TAD M4 /FOR FOUR DOTS
+ DCA DISCNT
+
+DISLOP, TAD XONEDS /ADD INCREMENT TO CURRENT X AND Y
+ TAD DIXTEM
+ DCA XONEDS /NOTE THAT THIS ROUTINE DESTROYS
+ TAD YONEDS /XONEDS AND YONEDS
+ TAD DIYTEM
+ DCA YONEDS
+ TAD XONEDS
+ RTR /DIVIDE BY 8 TO FIT SCREEN SIZE
+/ RAR
+ NOP
+/ DXC DXL /SET X VALUE
+ DILX /KKKK
+/ CLA
+ DCA LASTX
+ TAD YONEDS /DO THE SAME FOR Y
+ RTR
+/ RAR
+ NOP
+/ DYC DYL DIS /AT LAST SOMETHING TO SEE!!
+ DILY /KKKK
+/ CLA
+ DCA LASTY
+ ISZ DISCNT /DONE YET?
+ JMP DISLOP /NOPE
+ JMP I DISPLY /YUP
+
+
+DISHFT, 0 /A GENERALIZED SHIFT ROUTINE CALLED
+ CLL /FROM EVERYWHERE TO DIVIDE THE
+ SPA /AC BY FOUR WITH AN ASR RIGHT
+ CML IAC /NOTE THAT NEGATIVE NUMBERS ARE
+ RAR /ROUNDED UPWARDS (TOWARD ZERO)
+ CLL /TO MAKE IT COME OUT RIGHT
+ SPA
+ CML IAC /EVEN SO THERE ARE SOME ROUNDING ERRORS
+ RAR /SOMEWHERE. SO MUCH FOR 12 BIT MACHINES
+ JMP I DISHFT
+
+\f
+/
+/ HERE TO DISPLAY ALL THE PROJECTILES AND TEST FOR HITS.
+/ THE PROJECTILE DISPLAY FILE IS SEARCHED FOR PROJECTILES WITH
+/ NON-ZERO COUNTS AND WHEN ONE IS FOUND THE POSITION IS
+/ UPDATED BY THE VELOCITY, THE POINT DISPLAYED AND TESTED FOR
+/ A HIT.
+/
+
+ *1600
+
+PRODIS, CLA CLL / BEGIN DISPLAY OF THE PROJECTILES
+ TAD BUFST /POINT TO BEGINNING OF DISPLAY FILE
+ DCA BUFTMP
+ NOP / DSB 2 KKKK /SET EXTRA BRIGHT FOR SINGLE POINTS
+
+PROLOP, TAD I BUFTMP /PICK UP NEXT COUNT
+ SNA
+ JMP EXPIRE /THIS ONE IS DEAD - GO TO THE NEXT
+ IAC /INCREMENT COUNT AND REPLACE
+ DCA I BUFTMP
+ ISZ BUFTMP /BUMP POINTER TO X VELOCITY
+ TAD I BUFTMP
+ ISZ BUFTMP /THEN TO XPOSITION AND UPDATE X POSITION
+ TAD I BUFTMP /WITH THE VELOCITY WHICH IS CONSTANT
+ DCA I BUFTMP
+ TAD I BUFTMP
+ DCA PROX /AND STORE X POSITION FOR DISPLAY AND TEST
+ ISZ BUFTMP /NOW TO Y POSITION AND VELOCITY
+ TAD I BUFTMP
+ ISZ BUFTMP
+ TAD I BUFTMP /SAME LITTLE GAME
+ DCA I BUFTMP
+ TAD I BUFTMP
+ DCA PROY /STORE THE NEW Y VALUE
+
+ TAD PROX /DISPLAY THE POINT WITH
+ RTR /THE SAME SHIFT AS FOR THE SHIPS
+/ RAR /FOR THE SMALL SCREEN
+/ DXC DXL
+ DILX /KKKK
+ CLA
+ TAD PROY
+ RTR /
+/ RAR
+/ DYC DYL DIS /THERE IT IS!!
+ DILY /KKKK
+ CLA
+ JMS I CHKOUT /TEST FOR A HIT
+ ISZ BUFTMP /MOVE POINTER ON AND TEST FOR END
+ TAD BUFTMP /OF BUFFER
+ TAD BUFLIM
+ SZA CLA
+ JMP PROLOP /NOT AT END - CONTINUE
+
+\f/
+/ HERE AT THE END OF THE PROJECTILE DISPLAY. IF THE GAMOVR
+/ FLAG IS SET, GO ON TO THE MESSAGE DISPLAY - VICTORY LAP
+/ SECTION. OTHERWISE PICK UP THE REMAINING CLOCK COUNT
+/ TO GIVE THE FANS SOMETHING TO LOOK AT, AND MOVE THE
+/ ELECTRON BEAM TO A LOWER CORNER. THE COUNT DISPLAYED
+/ IN THE AC IS THE NUMBER OF 100 USEC CLOCK TICKS REMAINING
+/ WHEN THIS CODE IS REACHED BEFORE THE NEXT UPDATE WOULD
+/ BEGIN. TURNS OUT THAT ROUGHLY 2/3 OF THE CPU IS LEFT
+/ OVER SHOULD ANYONE WANT TO DO ANYTHING VERY FANCY.
+/
+
+
+FINISH, TAD GAMOVR /IS THIS THE VICTORY LAP OR WHAT?
+ SZA CLA
+ JMP I ENDGAM /YES, GO TO PUT UP THE MESSAGE
+ JMP I .+1
+ FINIS1
+ TAD M1000 /MOVE THE BEAM OFF SCREEN
+ DILX / DYC DYL KKKK
+ CLA CLL
+ TAD M1000
+ DILY / DXC DXL
+ DILX
+ JMP .-1
+/
+ENDGAM, JOBLOP
+
+\f
+
+EXPIRE, TAD BUFTMP /HERE TO ADVANCE THE BUFFER
+ TAD P5 /POINTER TO THE NEXT PROJECTILE
+ DCA BUFTMP /UNLESS THE END
+ TAD BUFTMP /OF THE BUFFER
+ TAD BUFLIM /IS REACHED
+ SZA CLA /IN WHICH CASE
+ JMP PROLOP /IT
+ JMP FINISH /QUITS
+
+BUFST, DISBUF+101
+BUFLIM, -DISBUF-175
+CHKOUT, CHECK
+
+RESE1, 0 /THIS IS CALLED TO SET THE POINTER
+ TAD MRES /(AUTO16) TO THE NEXT FREE SLOT
+ DCA RESCNT /FOR A PROJECTILE LAUNCH. 12 POSSIBLE
+
+RESLOP, TAD RESPNT /MOVE THE POINTER TO THE NEXT SLOT
+ TAD P5
+ DCA RESPNT
+ TAD RESPNT /RESTE IF AT END OF BUFFER
+ TAD BUFLIM
+ SZA CLA
+ JMP RESCON
+ TAD BUFST
+ DCA RESPNT
+
+RESCON, TAD I RESPNT /FIND A HOLE YET?
+ SNA CLA
+ JMP RESFND /YES, SET UP AUTO16
+ ISZ RESCNT /NO COUNT
+ JMP RESLOP /AND TRY AGAIN
+ HLT /NO HOLES AT ALL?
+
+RESFND, CMA /BACK THE POINTER FOR AUTO INDEXING
+ TAD RESPNT
+ DCA AUTO16
+ JMP I RESE1
+
+MRES, -14
+RESCNT, 0
+RESPNT, 0
+
+SETBUF, 0
+ CMA /THIS ROUTINE IS CALLED FROM THE
+ TAD BUFST /STARTING SEQUENCE TO INITIALIZE ALL
+ DCA AUTO16 /THE BUFFER POINTERS AND SO ON
+ TAD BUFST
+ DCA BUFTMP
+ TAD BUFST
+ DCA RESPNT
+ TAD BUFST
+ DCA SETPNT
+SETLOP, DCA I SETPNT
+ ISZ SETPNT
+ TAD SETPNT
+ TAD BUFLIM
+ SZA CLA
+ JMP SETLOP
+ JMP I SETBUF
+
+SETPNT, 0
+
+\f
+/
+/ THIS HERE NOW THING CHECKS THE COORDINATES OF THE MOST RECENTLY
+/ DISPLAYED PROJECTILE AGAINST THOSE OF THE SHIPS ON THE SCREEN.
+/ IF WITH A COLLISION LIMIT A HIT IS RECORDED AND THE LIFE
+/ COUNT OF THE PROJECTILE ZEROED TO REMOVE IT. A HIT SHIP
+/ IS SUITABLY FLAGGED
+/
+
+ *2000
+
+CHECK, 0 /HERE TO TEST FOR A PROJECTILE HIT
+ TAD ONEFLG /CANT HIT SOMETHING IN HYPERSPACE
+ SZA CLA
+ JMP CHECK2
+ TAD ONEOUT /OR SOMETHING THAT'S BEEN HIT
+ SZA CLA
+ JMP CHECK2
+
+ TAD PROX /CHECK X COORDINATES OF SHIP ONE
+ CIA /AND PROJECTILE
+ TAD ONEPEX /THIS SORT OF THING IS WHY THE
+ SPA /COORDINATES HAVE TO BE MAINTAINED TO 12
+ CIA /BITS
+ TAD LIMIT /CLOSE ENOUGH?
+ SMA CLA
+ JMP CHECK2 /IF X ISN' CLOSE ENOUGH THEN NO HIT
+ TAD PROY /X WAS CLOSE ENOUGH, HOW ABOUT Y?
+ CIA
+ TAD ONEPEY
+ SPA
+ CIA
+ TAD LIMIT
+ SMA CLA
+ JMP CHECK2 /NO HIT
+
+ TAD MEXP /DEPOSIT EXPLOSION COUNT IN ONEOUT
+ DCA ONEOUT /ALL THAT IS NECESSARY
+ JMS CUTOUT /REMOVE PROJECTILE
+
+\f
+
+CHECK2, TAD TWOFLG /NO HIT ON NUMBER ONE, TRY NUMBER TWO
+ SZA CLA
+ JMP I CHECK /BUT NOT IF IN HYPERSPACE
+ TAD TWOOUT /OR IF ALREADY HIT
+ SZA CLA
+ JMP I CHECK
+
+ TAD PROX /CHECK X'S FIRST
+ CIA
+ TAD TWOPEX
+ SPA /GET ABSOLUTE VALUE OF DIFFERENCE
+ CIA
+ TAD LIMIT /AND TEST MAGNITUDE AGAINST PROXIMITY
+ SMA CLA /LIMIT
+ JMP I CHECK /NOWHERE NEAR CLOSE
+
+ TAD PROY /NYAH, NYAH
+ CIA /TRY THE Y'S
+ TAD TWOPEY
+ SPA
+ CIA /ABSOLUTE VALUE OF DIFFERENCE
+ TAD LIMIT
+ SMA CLA
+ JMP I CHECK /CLEAN MISS!
+
+ TAD MEXP /HIT ON TWO - END EVERYTHING BY SETTING
+ DCA TWOOUT /TWOOUT TO NON-ZERO EXPLOSION COUNT
+ JMS CUTOUT
+ JMP I CHECK /EXIT AFTER DESTOYING PROJECTILE
+
+LIMIT, -120 /PROXIMITY LIMIT FOR WHAT CONSTITUTES A HIT
+
+CUTOUT, 0 /THIS ROUTINE ZEROES OUT THE MOST RECENTLY
+ TAD M4 /DISPLAYED PROJECTILE BY ZEROEING THE
+ TAD BUFTMP /COUNT
+ DCA CUTPNT
+ DCA I CUTPNT
+ JMP I CUTOUT
+
+CUTPNT, 0
+
+\f
+/
+/ THIS ROUTINE IS CALLED TO TEST FOR A COLLISION BETWEEN THE
+/ TWO SHIPS. THE COORDINATES OF BOTH ARE COMPARED
+/ AND IFF SUFFICIENTLY CLOSE BOTH ARE DESTROYED BY SETTING
+/ THEIR EXPLOSION COUNTS NON-ZERO.
+/
+
+
+COLLID, 0 /HERE TO TEST FOR COLLISION
+ TAD ONEFLG /NO TEST IF EITHER SHIP IS IN
+ SZA CLA /HYPERSPACE OR EXPLODING
+ JMP I COLLID
+ TAD TWOFLG
+ SZA CLA
+ JMP I COLLID
+ TAD ONEOUT
+ SZA CLA
+ JMP I COLLID
+ TAD TWOOUT
+ SZA CLA
+ JMP I COLLID
+
+ TAD ONEPEX /BOTH SHIPS AVAILABLE FOR COLLISION
+ CIA /CHECK X COORDINATES FIRST
+ TAD TWOPEX
+ SPA /GET ABSOLUTE VALUE OF DIFFERENCE
+ CIA
+ TAD COLLIM /CLOSE ENOUGH?
+ SMA CLA
+ JMP I COLLID /NOPE, FORGET IT
+
+ TAD ONEPEY /YES, NOW TRY THE Y COORDINATES
+ CIA
+ TAD TWOPEY
+ SPA
+ CIA /GET MAGNITUDE ONLY
+ TAD COLLIM
+ SMA CLA /CLOSE ENOUGH?
+ JMP I COLLID
+ TAD MEXP /YES, SET BOTH EXPLOSION COUNTS
+ DCA ONEOUT
+ TAD MEXP
+ DCA TWOOUT
+ JMP I COLLID
+
+COLLIM, -300
+\f
+/
+/ THIS ROUTINE IS CALLED TO SET ONE OF THE TWO SHIPS INTO
+/ HYPERSPACE. ON ENTRY THE AC=-1 FOR SHIP #1, 0 FOR SHIP
+/ NUMBER 2. THE LOCATION CLOCK IS USED FOR A RANDOM
+/ ADDRESS POINTER FROM WHICH WILL BE DRAWN THE
+/ VARIOUS PARAMETERS FOR REENTRY.
+/
+
+ *2200
+
+HYPSET, DCA RTNFLG /HERE WITH AC=-1 OR 0
+ TAD RTNFLG /SET UP LIST POINTER
+ SZA CLA
+ TAD ONEDIF /TO APPROPRIATE SHIP FILE
+ TAD TWOLST
+ DCA AUTO15
+
+ TAD CLOCK /SET UP "RANDOM NUMBER GENERATOR"
+ DCA AUTO17
+ TAD I AUTO17 /PICK UP FIRST THE AMOUNT OF TIME
+ AND TIMOUT /OUT OF NOMAL SPACE LIMITED TO -777
+ CIA /UPDATE CYCLES ( ABOUT 15 SECONDS)
+ DCA I AUTO15 /AND STORE IN ONEOUT OR TWO OUT
+
+ TAD I AUTO17 /THE NEXT RANDOM NUMBER BECOMES THE
+ JMS I THEADJ /ANGLE OR ORIENTATION ON REENTRY
+ DCA I AUTO15
+ TAD I AUTO17 /AND THE NEXT BECOMES THE X VELOCITY
+ JMS VEESET /COMPONENT
+ DCA I AUTO15
+ TAD I AUTO17 /AND THEN THE Y COMPONENT
+ JMS VEESET
+ DCA I AUTO15
+ TAD I AUTO17
+ DCA I AUTO15
+
+ TAD I AUTO17
+ DCA I AUTO15
+
+ TAD I AUTO17 /FINALLY SEE IF RETURN WILL BE SUCCESSFLY
+ AND TIMOUT
+ TAD MHYP /ABOUT 3/4 CHANCE
+ SMA CLA
+ JMP HYPRET /OK
+ TAD RTNFLG /THIS IS THE ONE TIME IN FOUR. SET
+ SZA CLA /UP FOR EXPLOSION ON REENTRY
+ TAD ONEDIF
+ TAD OUTLOC
+ DCA VEESET
+ TAD MEXP
+ DCA I VEESET
+
+HYPRET, ISZ RTNFLG
+ JMP I TWORTN
+ JMP I ONERTN
+
+TIMOUT, 777
+ONEDIF, ONEFLG-TWOFLG
+TWOLST, TWOFLG-1
+RTNFLG, 0
+ONERTN, TWOUP
+TWORTN, ONESET
+OUTLOC, TWOOUT
+MHYP, -200
+
+\f
+
+VEESET, 0 /HERE TO LIMIT VELOCITY COMPONENTS
+ CLL
+ SPA /GET MAGNITUDE
+ CML
+ AND HM177 /LIMIT TO 177
+ SZL CLL
+ CIA
+ JMP I VEESET /AND EXIT
+
+HM177, 177
+
+ONEEXP, CLA CLL /HERE TO DISPLAY SHIP NUMBER ONE AS
+ TAD ONETHE /AN EXPLOSION
+ TAD INCONE /FIRST ROTATE IT BY A GOOD DOLLOP
+ DCA ONETHE
+ JMS I IXPDIS /THEN CALL THE EXPLOSION GENERATOR
+ ISZ ONEOUT /DONE WITH THE EXPLOSION?
+ JMP I NOWTWO /NO, NORMAL RETURN
+
+ IAC /YES, SET INTO PSEUDO HYPER SPACE
+ DCA ONEFLG
+ IAC /DISABLE RETURN FROM HYPER SPACE
+ DCA ONEFIN
+
+ TAD TWOFIN /IS NUMBER TWO STILL AROUND?
+ SNA CLA
+ JMP I NOWTWO /YES, RETURN
+ JMP I TIEUP /NO, TIE BALL GAME
+\f
+
+TWOEXP, CLA CLL /HERE TO DISPLAY SHIP NUMBER TWO
+ TAD TWOTHE /AS AN EXPLOSION. BASH IT AROUND
+ TAD INCTWO
+ DCA TWOTHE
+ JMS I IXPDIS /THEN DISPLAY IT
+ ISZ TWOOUT /DONE WITH EXPLOSION?
+ JMP I NOWPRO /NO, NORMAL RETURN
+
+ IAC /YES, SEND INTO PSEUDO HYPER SPACE
+ DCA TWOFLG
+ IAC /DISABLE NORMAL RETURN FROM HYPERSPACE
+ DCA TWOFIN
+ /CHECK NUMBER ONE
+ TAD ONEFIN
+ SZA CLA /STILL ALIVE AND WELL?
+ JMP I TIEUP /NO, TIE GAME
+ JMP I NOWPRO /YES, CONTINUE ON
+NOWTWO, TWODIS
+NOWPRO, PRODIS
+TIEUP, NOWIN
+IXPDIS, EXPDIS
+INCONE, 55
+INCTWO, 55
+
+\f
+/
+/ HERE TO DISPLAY THE FIGURE POINTED TO BY AUTO10 AS
+/ AN EXPLOSION. THIS WORKS THE SAME WAY AS THE NORMAL
+/ DISPLAY ROUTINE EXCEPT THAT THE COORDINATE INCREMENTS
+/ ARE INVERTED TURNING THE FIGURE INSIDE OUT FOR S
+/ A SORT OF CLOBBY EXPLOSION.
+/
+
+ *2400
+
+EXPDIS, 0 /HERE TO DISPLAY A FIGURE INSIDE OUT
+ TAD I AUTO10 /WITH THE POINTERS AND COUNTS ALREADY
+ DCA XTWODS /SET UP BY FILDIS OR TWODIS
+ TAD I AUTO10 /STICK NEXT TWO POINTS INTO LINE
+ DCA YTWODS
+
+ TAD XTWODS
+ CIA /CALCULATE INCREMENT THE WRONG WAY
+ TAD XONEDS
+ DCA DIXTEM /AND STORE
+ TAD YTWODS
+ CIA
+ TAD YONEDS
+ DCA DIYTEM /SAME FOR Y
+
+ TAD M4 /4 DOTS IN THE VECTOR"
+ DCA DISCNT /COULD HAVE CALLED THE OTHER
+ /VECTOR GENERATOR I SUPPOSE
+EXPLOP, TAD XONEDS
+ TAD DIXTEM /ADD X AND Y INCREMENTS TO THE RUNNING
+ DCA XONEDS /TOTALS AND DISPLAY THE RUNNING
+ TAD YONEDS /TOTALS NORMAL SIZE
+ TAD DIYTEM
+ DCA YONEDS
+
+ TAD XONEDS
+ RTR /COULD MAKE TWICE AS BIG BY NOP-ING
+ NOP / RAR /THE RAR'S BUT THE SCREEN IS SMALL ENOUGH
+ DILX / DXC DXL KKKK /AS IT IS
+ CLA
+ TAD YONEDS
+ RTR
+ NOP / RAR
+ DILY / DYC DYL DIS
+ CLA
+ ISZ DISCNT /DONE 4 DOTS?
+ JMP EXPLOP /NO
+
+ ISZ AUTO11 /DONE ALL VECTORS IN THE FILE?
+ SKP
+ JMP I EXPDIS /YES, EXIT
+
+ TAD XTWODS /NO SWAP TO NEXT PAIR OF POINTS
+ DCA XONEDS
+ TAD YTWODS
+ DCA YONEDS
+ JMP EXPDIS+1
+
+
+\f
+/
+/ VEELIM IS THE SCALING ROUTINE FOR VELOCITY COMPONENTS.
+/ THE COMPONENTS ARE SCALED TO REMAIN IN THE RANGE 140
+/ TO -140. THIS IS NECESSARY TO AVOID ASTRONOMICAL SPPED
+/ BUILDUP ON THE SMALL SCREEN. UNFORTUNATELY THE X AND Y
+/ COMPONENTS ARE SCALED SEPARATELY WHICH GIVES SLIGHT BUT
+/ NOTICABLE DISTORTIONS IN DIAGONAL FLIGHT PATHS. IN THE
+/ NORMAL HEAT OF THE BATTLE NO ONE WILL REALLY NOTICE.
+/
+
+
+VEELIM, 0 /ENTER TO SCALE VELOCITY HELD IN
+ DCA VEEHLD /AC
+ TAD VEEHLD
+ SMA /BRANCH FOR POSITIVE OR NEGATIV
+ JMP VEEPOS
+ TAD VEEMAX
+ SMA CLA /GREATER THAN MAXIMUM POSITIVE?
+ JMP VEECLR /NO
+ TAD VEEMIN /I MEAN MAXIMUM NEGATIVE - YES SET
+ JMP I VEELIM /TO MAX NEGATIV
+
+VEEPOS, TAD VEEMIN /GREATER THAN MAX?
+ SPA CLA
+ JMP VEECLR /NO
+ TAD VEEMAX /YES SET TO MAX
+ JMP I VEELIM
+
+VEECLR, TAD VEEHLD /IT WAS IN RANGE ALL ALONG
+ JMP I VEELIM
+
+VEEHLD, 0
+VEEMIN, -140
+VEEMAX, 140
+
+THEAJI, 0 /HERE TO ADJUST THE ANGLE TO A RANGE
+ SMA /0-550 OR 0-360 DEGREES. THIS IS
+ JMP .+3 /NECESSARY TO INSURE THAT PUSHDOWN OVERFLOW
+ TAD P550 /WILL NOT HAPPEN IN THE SINE AND COSINE
+ JMP .-3 /ROUTINES. THIS SIMPLY TAKES THE AC
+ TAD M550 /MODULO 360 AND EXITS
+ SMA
+ JMP .-2
+ TAD P550 /FOLLOW IT THROUGH AND SEE IF IT DOESN'T
+ JMP I THEAJI
+
+\f
+/
+/ ONE OF THESE ROUTINE IS ENTERED WHEN A WINNER IS DECLARED.
+/ THE ADDRESS OF THE VICTORY MESSAGE IS PLACED IN MESS AND
+/ THE GAMOVR FLAG SET TO CAUSE A BRANCH TO JOBLOP WHEN THE
+/ DISPLAY CYCLE IS COMPLETED. THE ROUTINE WILL THEN DISPLAY
+/ THE APPROPRIATE MESSAGE OVER THE REMAINING SHIPS IF
+/ ANY UNTIL THE KEYBOARD IS MOLESTED OR THE CLOCK RUNS OUT
+/ AND THE NEXT DISPLAY UPDATE CYCLE IS SET. AT ANY RATE THE
+/ PROGRAM WILL REACH HERE ONLY WHEN SOMEONE HAS BITTEN THE
+/ INTERGALACTIC DUST.
+/
+
+
+ONEWIN, 0 /THIS IS CALLED WHEN TWOFIN IS SET
+ TAD MES1 /AND ONE FIN IS NOT. SET ONE TO VICTOR
+ DCA MESS /AND SET GAMOVR FLAG
+ IAC
+ DCA GAMOVR
+ TAD MESS6+3
+ JMS INCREM
+ DCA MESS6+3
+ DCA PNTCNT
+ JMP I ONEWIN /THEN RETURN TO UPDATE CYCLE
+
+TWOWIN, 0 /THIS IS CALLED WHEN ONEFIN IS SET
+ TAD MES2 /AND TWO FIN IS NOT
+ DCA MESS /SET ALSO GAMOVR
+ IAC
+ DCA GAMOVR
+ TAD MESS6+1
+ JMS INCREM
+ DCA MESS6+1
+ DCA PNTCNT
+ JMP I TWOWIN
+/
+INCREM, 0
+ TAD PNTCNT
+ BSW
+ TAD P600
+ SMA
+ TAD P6601
+ TAD M600
+ BSW
+ JMP I INCREM
+/
+NOWIN, TAD MES4 /GET HERE WHEN BOTH ONEFIN AND TWOFIN
+ DCA MESS /ARE SET .
+ IAC
+ DCA GAMOVR /NOBODY EVER REALLY WINDS
+ /UP THE WINNER IN THESE THINGS
+JOBLOP, JMP IDLE / DSB 1 KKKK /THIS IS ENTERED FROM FINISH WH
+ TAD MES0 /GAMOVR IS SET AND SERVES TO DISPLAY
+ JMS I MESOUT /THE VICTORY MESSAGE ON THE SCREEN
+ TAD MESS /USING THE CHARACTER GENERATOR SOMEWHAT
+ JMS I MESOUT /FURTHER ON UNTIL THE GAME IS RESTARTED
+ TAD MES5 /OR UNTIL THE INTERRUPT COUNT OVERFLOWS
+ JMS I MESOUT /AND THE UPDATE CYCLE IS RESTARTED
+ TAD MES3
+ JMS I MESOUT
+ TAD MES6
+ JMS I MESOUT
+FINITO, JMP JOBLOP
+
+MES0, MESS0
+MES1, MESS1
+MES2, MESS2
+MES3, MESS3
+MES4, MESS4
+MES5, MESS5
+MES6, MESS6
+MESS6, 5473
+ 6060
+ 4040
+ 6060
+ 0
+\f
+/
+/ THE FOLLOWING ARE THE SINE AND COSINE ROUTINES CUSTOMIZED
+/ FOR THIS PROGRAM FROM ANOTHER I WORKED ON. CALL EITHER
+/ SINE OR COSINE WITH ANGLE IN DEGREES IN AC. THE ARGUEMENT
+/ IS REDUCED THROUGH RECURSION UNTIL BETWEEN 0-89 DEGREES
+/ AND THEN A TABLE LOOKUP DONE TO OBTAIN THE VALUE. IT TAKES
+/ UP A FAIR AMOUNT OF SPACE BUT IT WORKS JUST FASTER
+/ THAN SHEEP. THE COSINE CALL JUST TRANSFORMS THE ARGUEMENT
+/ THROUGH SOME TRIGONOMETRIC GARBAGE AND CALLS THE SINE
+/ ROUTINE. NOTE THAT CALLING EITHER ROUTINE WITH TOO
+/ LARGE AN ARGUEMENT WILL CAUSE PUSHDOWN OVERFLOW AND THEN
+/ ALL HELL WILL BREAK LOOSE. THE ORIGINAL ROUTINE FROM WHICH
+/ THIS WAS STOLEN HAD FULL WORD PRECISION.
+/
+
+ *6400
+
+SINEIN, 0 /I REALLY CANT BRING MYSELF TO COMMENT
+ DCA SINARG /THIS. IT'S VERY STRAIGHFORWARD
+ TAD SINEIN
+ DCA I SINPSH
+ ISZ SINPSH
+ TAD SINARG
+ SZA
+ JMP SINNG2
+
+SINPOP, CLA CLL CMA
+ TAD SINPSH
+ DCA SINPSH
+ TAD I SINPSH
+ DCA SINEIN
+ TAD SINARG
+ JMP I SINEIN
+
+SINNG2, SMA
+ JMP SINPOS
+ CIA
+ JMS SINEIN
+
+SINNEG, CIA
+ DCA SINARG
+ JMP SINPOP
+
+SINPOS, TAD M264
+ SPA
+ JMP .+2
+ JMP SINNEG-1
+ TAD P132
+ SPA
+ JMP SINELK
+ SZA CLA
+ JMP .+3
+ TAD P37
+ JMP SINNEG+1
+
+ TAD SINARG
+ TAD M264
+ JMP SINNEG-1
+
+SINELK, TAD P132
+ TAD SINTAB
+ DCA SINEIN
+ TAD I SINEIN
+ DCA SINARG
+ JMP SINPOP
+
+\f
+
+SINARG, 0
+SINPSH, SINLST
+SINLST, 0
+ 0
+ 0
+ 0
+ 0
+ 0
+
+SINTAB, SINES-1
+
+COSINI, 0
+ CIA
+ TAD P132
+ JMS SINEIN
+ JMP I COSINI
+
+
+
+SINES, 00 /1
+ 01 /2
+ 01 /3
+ 02 /4
+ 02 /5
+ 03 /6
+ 03 /7
+ 04 /8
+ 05 /9
+ 05 /10
+ 06 /11
+ 06 /12
+ 07 /13
+ 07 /14
+ 10 /15
+ 10 /16
+ 11 /17
+ 11 /18
+ 12 /19
+ 12 /20
+ 13 /21
+ 13 /22
+ 14 /23
+ 15 /24
+ 15 /25
+ 16 /26
+ 16 /27
+ 17 /28
+ 17 /29
+ 20 /30
+ 20 /31
+ 20 /32
+ 21 /33
+ 21 /34
+ 22 /35
+ 22 /36
+ 23 /37
+ 23 /38
+ 24 /39
+ 24 /40
+ 25 /41
+ 25 /42
+ 25 /43
+ 26 /44
+ 26 /45
+ 27 /46
+ 27 /47
+ 27 /48
+ 30 /49
+ 30 /50
+ 30 /51
+ 31 /52
+ 31 /53
+ 31 /54
+ 32 /55
+ 32 /56
+ 32 /57
+ 33 /58
+ 33 /59
+ 33 /60
+ 33 /61
+ 34 /62
+ 34 /63
+ 34 /64
+ 35 /65
+ 35 /66
+ 35 /67
+ 35 /68
+ 35 /69
+ 36 /70
+ 36 /71
+ 36 /72
+ 36 /73
+ 36 /74
+ 36 /75
+ 37 /76
+ 37 /77
+ 37 /78
+ 37 /79
+ 37 /80
+ 37 /81
+ 37 /82
+ 37 /83
+ 37 /84
+ 37 /85
+ 37 /86
+ 37 /87
+ 37 /88
+ 37 /89
+
+\f
+
+MULTI, 0 /THIS IS STANDARD SINGLE PRECISION
+ CLL /MULTIPLY ROUTINE WHICH WAS ONCE
+ SPA /USED. I'VE LEFT IT IN SINCE
+ CMA CML IAC /THERE IS LOTS OF CORE LEFT OVER AND
+ DCA MULMP1 /MAYBLE SOMEDAY I'LL NEED IT TO PUT
+ DCA MULMP5 /IN A SUN OR SOMETHING. THIS IS THE
+ TAD I MULTI /STANDARD DEC SUBROUTINE WITH DIFFERENT
+ SNA /LABELS
+ JMP MULPSN+2
+ SPA
+ CMA CML IAC
+ DCA MULMP2
+ TAD MULTHR
+ DCA MULMP3
+
+MULMP4, TAD MULMP1
+ RAR
+ DCA MULMP1
+ TAD MULMP5
+ SZL
+ TAD MULMP2
+ CLL RAR
+ DCA MULMP5
+ ISZ MULMP3
+ JMP MULMP4
+ TAD MULMP1
+ RAR
+MULPSN, SZL
+ JMP MULCMP
+ DCA MULMP1
+ TAD MULMP5
+MULMPZ, ISZ MULTI
+ JMP I MULTI
+
+MULCMP, CMA CLL IAC
+ DCA MULMP1
+ TAD MULMP5
+ CMA
+ SZL
+ IAC
+ JMP MULMPZ
+
+MULTHR, 7764
+MULMP1, 0
+MULMP5, 0
+MULMP2, 0
+MULMP3, 0
+
+\f
+/
+/ SHIFTR DIVIDES THE AC BY TWO WHETHER POSITIVE OR NEGATIVE
+/ AND IS CALLED FROM VARIOUS PLACES. NOT ENTIRELY MYSTERIOUS
+/
+
+
+SHIFTR, 0
+ CLL
+ SPA
+ CML IAC
+ RAR
+ JMP I SHIFTR
+
+
+/
+/ POSCAL IS CALLED TO CALCULATE THE COORDINATE INCREMENTS
+/ NECESSARY TO PRODUCE THE SHIP FIGURES. RATHER THAN DOING
+/ A LOT OF EXPENSIVE MATH THIS DOES A QUICK PRODUCTION
+/ OF 1, 2, AND 3 TIMES THE SIN AND COSINE VALUES FOUND
+/ IN CALSIN AND CALCOS LEAVING THEM IN THE TABLE FOR
+/ ONESET AND TWOSET. IF THE SCOPE WERE ANY BETTER
+/ THIS PROBABLY WOULDN'T BE NEAR GOOD ENOUGH BUT....
+/
+
+POSCAL, 0
+ TAD CALSIN
+
+ DCA T10SIN
+ TAD T10SIN
+ CLL RAL
+ DCA T20SIN
+ TAD T10SIN
+ TAD T20SIN
+ DCA T30SIN
+
+ TAD CALCOS
+
+ DCA T10COS
+ TAD T10COS
+ CLL RAL
+ DCA T20COS
+ TAD T10COS
+ TAD T20COS
+ DCA T30COS
+ JMP I POSCAL
+
+\f
+ *7000
+
+/GENERAL PURPOSE SYMBOL GENERATOR
+/
+CHARS, 0 /ENTRY TO PLOT CHARACTER STRING
+ DCA ADDR /STORE STRING ADDRESS
+ TAD I ADDR /FETCH DOUBLE CHARACTER
+ RTR /SHIFT
+ RTR / FOR FIRST
+ RTR / CHARACTER
+ JMS CHAR /PLOT CHARACTER
+ SKP /NORMAL RETURN -- SKIP
+ JMP I CHARS /TERMINATION RETURN -- EXIT
+ TAD I ADDR /RECALL DOUBLE CHARACTER
+ ISZ ADDR /ADVANCE STRING ADDRESS
+ JMS CHAR /PLOT CHARACTER
+ JMP CHARS+2 /NORMAL RETURN -- REPEAT
+ JMP I CHARS /TERMINATION RETURN -- EXIT
+/
+CHAR, 0 /ENTRY TO PLOT SINGLE CHARACTER
+ AND K77 /MASK OUT UPPER BITS
+ CLL RAL /MULTIPLY CODE BY TWO
+ TAD TABLE /ADD TABLE BASE ADDRESS
+ DCA POINT /CONSTRUCT POINTER TO 24-BIT CODE
+ CMA /INITIALIZE COUNTER FOR
+ DCA COUNT2 / TWO PLOT WORDS
+ TAD I POINT /FETCH FIRST PLOT WORD
+ ISZ POINT /INCREMENT POINTER FOR NEXT ONE
+ SNA /SKIP IF NOT SPECIAL CHARACTER
+ JMP SPCHAR /ELSE GO PROCESS IT
+ DCA CURPLT /SAVE CURRENT PLOT BITS
+XPLOT, TAD KM6 /INITIALIZE 6-BIT
+ DCA COUNT6 / COUNTER
+ TAD YVALUE /RESET Y TEMPORARY
+ DCA YTEMP / VALUE FOR CHARACTER
+ TAD XVALUE /OUTPUT CURRENT
+ RAL
+ MQL
+ MQA
+/ DILX / DXC DXL / KKKK X-VALUE TO CRT
+ RAR
+ TAD XINCR /INCREMENT
+ DCA XVALUE / ABSCISSA
+YPLOT, TAD CURPLT /RECALL CURRENT PLOT BITS
+ CLL RAL /GET NEXT BIT
+ DCA CURPLT /SAVE REMAINING PLOT BITS
+ SNL /SKIP IF POINT TO PLOT
+ JMP CNTINU /ELSE JUMP AHEAD
+ TAD YTEMP /OUTPUT CURRENT
+ RAL
+ DILY / DYC DYL DIS /KKKK / Y-VALUE TO CRT
+ MQA CLA
+ DILX
+ CLA CLL /CLEAR AC
+ TAD CURPLT /RECALL CURRENT PLOT BITS
+ SNA CLA /SKIP IF POINTS REMAINING
+ JMP WRDEND /ELSE WORD IS FINISHED
+CNTINU, TAD YTEMP /INCREMENT TEMPORARY
+ TAD YINCR / Y-VALUE FOR NEXT
+ DCA YTEMP / CHARACTER STEP
+ ISZ COUNT6 /SKIP IF 6 BITS PLOTTED
+ JMP YPLOT /ELSE PLOT NEXT ONE
+ JMP XPLOT /GO UPDATE X-VALUE
+WRDEND, ISZ COUNT2 /SKIP IF ANOTHER BIT WORD
+\f JMP EXIT /ELSE EXIT
+ TAD I POINT /FETCH SECOND BIT WORD
+ SZA /SKIP IF NO PLOT POINTS
+ JMP XPLOT-1 /ELSE GO PLOT THEM
+EXIT, TAD XVALUE /INCREMENT ABSCISSA
+ TAD XINCR / FOR SPACE BETWEEN
+ DCA XVALUE / SYMBOLS
+ JMP I CHAR /EXIT FROM CHAR
+/
+SPCHAR, TAD I POINT /FETCH TRANSFER VECTOR
+ DCA POINT /STORE AS INDIRECT ADDRESS
+\f JMP I POINT /GO TO APPROPRIATE ROUTINE
+SPACE, TAD XINCR /FETCH BASIC ABSCISSA INCREMENT
+ CLL RTL /MULTIPLY BY FOUR AND
+ JMP EXIT / GO CREATE SPACE
+CRLF, TAD INITX /"CARRIAGE RETURN" RESETS X
+ DCA XVALUE / TO ITS ORIGINAL VALUE
+LF, TAD YINCR /"LINE FEED"
+ CLL RTL / DECREMENTS THE
+ CLL CIA RAL / Y-VALUE BY
+ TAD YVALUE / EIGHT SCALE
+ DCA YVALUE / STEPS
+ JMP I CHAR /EXIT FROM CHAR
+RESET, TAD INITX /"RESET" RESETS
+ DCA XVALUE / X AND Y TO
+ TAD INITY / THEIR ORIGINAL
+ JMP RESET-2 / VALUES
+TERM, ISZ CHAR /TERMINATE CODE CAUSES
+ JMP I CHAR / EXIT TO P+2
+/
+INITX, -150 /INITIAL X-VALUE
+INITY, 327 /INITIAL Y-VALUE
+XVALUE, 0 /CURRENT X-VALUE
+YVALUE, 0 /CURRENT Y-VALUE
+XINCR, 6 /BASIC X INCREMENT VALUE
+YINCR, 10 /BASIC Y INCREMENT VALUE
+YTEMP, 0 /TEMPORARY Y-VALUE
+CURPLT, 0 /CURRENT PLOT BITS
+ADDR, 0 /CURRENT STRING ADDRESS
+COUNT6, 0 /6-BIT COUNTER
+COUNT2, 0 /2-WORD COUNTER
+KM6, -6 /CONSTANT FOR COUNT6
+K77, 77 /CHARACTER CODE MASK
+POINT, 0 /TABLE POINTER
+/
+\f
+/
+TABLE, .+1 /TABLE BASE ADDRESS
+ 0 /SPECIAL CHARACTER (00)
+ TERM /TERMINATION CODE
+ 7611 / A
+ 1176
+ 7745 / B
+ 4532
+ 3641 / C
+ 4122
+ 7741 / D
+ 4136
+ 7745 / E
+ 4541
+ 7705 / F
+ 501
+ 7741 / G
+ 5173
+ 7710 / H
+ 1077
+ 4177 / I
+ 4100
+ 2040 / J
+ 4037
+ 7714 / K
+ 2241
+ 7740 / L
+ 4040
+ 7702 / M
+ 277
+ 7706 / N
+ 3077
+ 7741 / O
+ 4177
+ 7705 / P
+ 502
+ 3641 / Q
+ 6176
+ 7715 / R
+ 2542
+ 2245 / S
+ 5122
+ 177 / T
+ 100
+ 3740 / U
+ 4037
+ 1720 / V
+ 4037
+ 7730 / W
+ 3077
+ 4136 / X
+ 3641
+ 374 / Y
+ 7403
+ 6151 / Z
+ 4543
+ 7741 / [
+ 0
+ 204 / \
+ 1020
+ 4177 / ]
+ 0
+ 436 / ^
+ 400
+ 0 /SPECIAL CHARACTER (37)
+ RESET /RESET
+ 0 /SPECIAL CHARACTER (40)
+ SPACE /SPACE
+ 5600 / !
+ 0
+ 303 / "
+ 0
+ 1477 / #
+ 7714
+ 2277 / MARKER
+ 2200
+ 2313 / %
+ 6462
+ 7777 / BLOCK
+ 7777
+ 300 / '
+ 0
+ 3641 / (
+ 0
+ 4136 / )
+ 0
+ 4040 / UNDERSCORE (52)
+ 4040
+ 1034 / +
+ 1000
+ 0 /SPECIAL CHARACTER (54)
+ LF /LINE FEED
+ 1010 / -
+ 1000
+ 4000 / .
+ 0
+ 2010 / /
+ 402
+ 3641 / 0
+ 4136
+ 4442 / 1
+ 7740
+ 4261 / 2
+ 5146
+ 2145 / 3
+ 5321
+ 1710 / 4
+ 1077
+ 4745 / 5
+ 4531
+ 7750 / 6
+ 5070
+ 6111 / 7
+ 503
+ 2255 / 8
+ 5522
+ 705 / 9
+ 577
+ 2400 / :
+ 0
+ 0 /SPECIAL CHARACTER (73)
+ CRLF /CARRIAGE RETURN; LINE FEED
+ 1024 / >
+ 4200
+ 1212 / =
+ 1200
+ 4224 / <
+ 1000
+ 255 / ?
+ 300
+
+\f
+/
+/ HERE FOLLOW THE PACKED ASCII TEXTS FOR THE VARIOUS
+/ VICTORY MESSAGES. PERSONS ADVENTEROUS TO FIND THIS MIGH CARE
+/ TO TOGGLE IN SOME CUTE LITTLE MESSAGES OF THEIR OWN.
+/
+
+MESS0, 3773
+MESS5, 7340
+ 0
+/ 4040
+/ 4040
+/ 4000
+
+MESS1, 2427 /"TW"
+ 1700 /"O\"
+
+MESS2, 1716 /"ON"
+ 0500 /"E\"
+
+MESS3, 2711 /"WI"
+ 1623 /"NS"
+ 4100 /"!\"
+
+MESS4, 1617 /"NO"
+ 0217 /"BO"
+ 0431 /"DY"
+ 0000 /"\"
+
+\f
+ *4000
+/ KK: ADDED STARS IN THE SKY
+/
+FINIS1, TAD I SB
+ RAR / SCALE COORDINATES
+ TAD M1000 / SHIFT TO LEFT
+ MQL
+ CLA CLL
+ ISZ SB
+ TAD I SB
+ SNA
+ JMP FINIS3 / END OF STARS
+ RAR / SCALE COORDINATES
+ TAD M1000 / SHIFT DOWN
+ DILY
+ MQA CLA
+ DILX
+ ISZ SB
+ CLA CLL
+ TAD M100 / A LITTLE DELAY
+FINIS2, IAC
+ SZA
+ JMP FINIS2
+ JMP FINIS1
+/
+FINIS3, TAD SBI / REINITIALIZE STAR-POINTER
+ DCA SB
+ TAD ONE2 / AT THE REAL END:
+ CMA / POSITION DOT EITHER TO
+ DCA ONE2 / SHIP1 OR SHIP2
+ TAD ONE2
+ SNA CLA
+ JMP FINIS4
+ TAD LASTX
+ DILX
+ CLA
+ TAD LASTY
+ DILY
+ JMP .
+FINIS4, TAD LASTX1
+ DILX
+ CLA
+ TAD LASTY1
+ DILY
+ JMP .
+ONE2, 0
+/
+/ STARS COME FROM THE 24-VOLUME "DTV-TASCHENLEXIKON"
+/
+ *4200
+ DECIMAL
+STARS, / PEGASUS
+ 425; 1665
+ 490; 1730
+ 615; 1740
+ 682; 1735
+ 920; 1770
+ 725; 1615
+ 680; 1575
+ 425; 1665
+ 682; 1735
+ 725; 1615
+ /CANCER
+ 1500; 632
+ 1365; 615
+ 1445; 585
+ 1445; 545
+ /URSA MAJ.
+ 725; 640
+ 725; 640
+ 800; 665
+ 800; 665
+ 855; 660
+ 855; 660
+ 885; 685
+ 975; 740
+ 975; 740
+ 925; 640
+ 925; 640
+ 990; 690
+ 990; 690
+ 1000; 570
+ 1110; 560
+ 1150; 590
+ 1140; 700
+ 1200; 700
+ 1200; 730
+ /ORION
+ 1710; 1180
+ 1710; 1180
+ 1680; 1130
+ 1730; 1080
+ 1730; 1080
+ /SERPENS
+ 190; 520
+ 230; 510
+ 230; 510
+ 280; 490
+ 300; 560
+ /OPHIUCHUS
+ 100; 1000
+ 60; 880
+ 130; 885
+ 130; 885
+ 130; 750
+ /ERIDANUS
+ 1660; 1730
+ 1700; 1680
+ 1740; 1630
+ 1810; 1600
+ /POLARSTERN
+ 950; 1025
+ 950; 1025
+ 859; 1011
+ 810; 975
+ 719; 939
+ 800; 932
+ 750; 882
+ 790; 870
+ 790; 870
+ /EICHUNG
+/ 1; 1
+/ 2000; 1
+/ 2000; 2000
+/ 1; 2000
+ 0; 0
+ OCTAL
+ *7400
+
+DISBUF, 0
+
+/ THE DISPLAY BUFFERS BEGIN HERE AND EXTEND UP SOMEWHERE TO
+/ AROUND 7575 OR SO.
+/
+/
+/
+/
+/
+
+
+
+ $
+
+////////////////////////////
+/
+/ THIS IS THE END
+/
+///////////////////////////
+
+\f
\ No newline at end of file
projects / pdp8.git / commitdiff