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| 15 | |
| 16 | OS/8 FORTRAN IV |
| 17 | |
| 18 | SOFTWARE SUPPORT MANUAL |
| 19 | |
| 20 | |
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| 36 | |
| 37 | |
| 38 | DISCLAIMER |
| 39 | |
| 40 | This document file was created by scanning the |
| 41 | original document and then editing the scanned |
| 42 | text. As much as possible, the original text |
| 43 | format was restored. Some format changes were |
| 44 | made to insure this document would print on |
| 45 | current laser printers using 60 lines per page, |
| 46 | which changed the page numbering. The original |
| 47 | spelling and grammar have been preserved. |
| 48 | |
| 49 | |
| 50 | 1-NOV-1997 |
| 51 | \f |
| 52 | |
| 53 | DEC-S8-LFSSA-A-D |
| 54 | |
| 55 | AA-4532A-TA 056573 |
| 56 | |
| 57 | |
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| 70 | |
| 71 | |
| 72 | |
| 73 | OS/8 FORTRAN IV |
| 74 | |
| 75 | SOFTWARE SUPPORT MANUAL |
| 76 | |
| 77 | |
| 78 | |
| 79 | |
| 80 | |
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| 100 | |
| 101 | |
| 102 | ---------------------------------------------------------- |
| 103 | | For additional copies, order No. DEC-S8-LFSSA-A-D | |
| 104 | | from Software Distribution Center, Digital Equipment | |
| 105 | | Corporation, Maynard, Mass. | |
| 106 | ---------------------------------------------------------- |
| 107 | |
| 108 | |
| 109 | digital equipment corporation - maynard, massachusetts |
| 110 | \f |
| 111 | |
| 112 | |
| 113 | First Printing |
| 114 | June, 1973 |
| 115 | |
| 116 | |
| 117 | |
| 118 | |
| 119 | |
| 120 | |
| 121 | |
| 122 | |
| 123 | |
| 124 | |
| 125 | |
| 126 | |
| 127 | |
| 128 | |
| 129 | |
| 130 | Copyright (c) 1973 by Digital Equipment Corporation |
| 131 | |
| 132 | |
| 133 | |
| 134 | |
| 135 | |
| 136 | |
| 137 | |
| 138 | |
| 139 | |
| 140 | |
| 141 | |
| 142 | |
| 143 | |
| 144 | |
| 145 | |
| 146 | The following are trademarks of Digital Equipment Corporation, |
| 147 | Maynard, Massachusetts: |
| 148 | |
| 149 | CDP DIGITAL KA10 PS/8 |
| 150 | COMPUTER LAB DNC LAB-8 QUICKPOINT |
| 151 | COMTEX EDGRIN LAB-8/e RAD-8 |
| 152 | COMSYST EDUSYSTEM LAB-K RSTS |
| 153 | DDT FLIP CHIP OMNIBUS RSX |
| 154 | DEC FOCAL OS/8 RTM |
| 155 | DECCOMM GLC-8 PDP SABR |
| 156 | DECTAPE IDAC PHA TYPESET 8 |
| 157 | DIBOL IDACS UNIBUS |
| 158 | INDAC |
| 159 | |
| 160 | |
| 161 | |
| 162 | |
| 163 | |
| 164 | |
| 165 | |
| 166 | |
| 167 | |
| 168 | ii |
| 169 | \f |
| 170 | |
| 171 | |
| 172 | CONTENTS |
| 173 | |
| 174 | |
| 175 | |
| 176 | |
| 177 | CHAPTER 1 THE F4 COMPILER 1-1 |
| 178 | |
| 179 | CHAPTER 2 THE RALF ASSEMBLER 2-1 |
| 180 | |
| 181 | CHAPTER 3 THE FORTRAN IV LOADER 3-1 |
| 182 | |
| 183 | CHAPTER 4 THE FORTRAN IV RUN-TIME SYSTEM 4-1 |
| 184 | |
| 185 | CHAPTER 5 LIBRA AND FORLIB 5-1 |
| 186 | |
| 187 | APPENDIX A RALF Assembler Permanent Symbol Table A-1 |
| 188 | |
| 189 | APPENDIX B Assembly Instructions B-1 |
| 190 | |
| 191 | |
| 192 | |
| 193 | |
| 194 | |
| 195 | |
| 196 | |
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| 198 | |
| 199 | |
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| 220 | |
| 221 | |
| 222 | |
| 223 | |
| 224 | |
| 225 | |
| 226 | |
| 227 | iii |
| 228 | \f |
| 229 | |
| 230 | |
| 231 | CHAPTER 1 |
| 232 | |
| 233 | THE F4 COMPILER |
| 234 | |
| 235 | |
| 236 | The OS/8 F4 compiler runs in 8K on either a PDP-8 or a PDP-12. It |
| 237 | operates in three passes to transform FORTRAN IV source programs into |
| 238 | RALF assembly language. The function of each of the three passes is: |
| 239 | |
| 240 | 1. Analyze statements, check syntax and convert to a polish |
| 241 | notation. |
| 242 | |
| 243 | 2. Convert output of PASS1 to RALF assembly language making |
| 244 | extensive use of code skeleton tables. |
| 245 | |
| 246 | 3. Produce a listing of the FORTRAN source program and/or chain |
| 247 | to the assembler. |
| 248 | |
| 249 | The following is a more complete description of each of the three |
| 250 | passes. |
| 251 | |
| 252 | |
| 253 | |
| 254 | PASS1 OPERATION |
| 255 | |
| 256 | After opening the source language input file(s) and an intermediate |
| 257 | output file, PASS1 processes statements in the following fashion: |
| 258 | |
| 259 | 1. Assemble a statement into the statement buffer by reading |
| 260 | characters from the OS/8 input file. This section eliminates |
| 261 | comments and handles continuations so that the statement |
| 262 | buffer contains the entire statement as if it had been |
| 263 | written on one long line. |
| 264 | |
| 265 | 2. The statement is first assumed to be an arithmetic assignment |
| 266 | and an attempt is made to compile it as such. This is done |
| 267 | with a special switch (NOCODE) set so that in the event the |
| 268 | statement is not arithmetic, no erroneous output is produced. |
| 269 | Thus, with this switch set, the expression analyzer |
| 270 | subroutine is used merely as a syntax checker. |
| 271 | |
| 272 | 3. If the statement is indeed an arithmetic assignment statement |
| 273 | (or arithmetic statement function) the switch is set off and |
| 274 | the statement is then recompiled, this time producing output. |
| 275 | |
| 276 | 4. If not an arithmetic assignment, the statement might be one |
| 277 | of the keyword defined statements. The compiler now checks |
| 278 | the first symbol on the line to see of it is a legal keyword |
| 279 | (REAL, GOTO, etc.) and jumps to the appropriate subroutine if |
| 280 | so. Any statement that is not now classified is considered |
| 281 | to be in error. |
| 282 | |
| 283 | 5. The compilation of each statement takes place. Some state- |
| 284 | ments produce only symbol table entries (e.g., DIMENSION) |
| 285 | |
| 286 | 1-1 |
| 287 | \f |
| 288 | |
| 289 | |
| 290 | which will be processed by PASS2. Others use the arithmetic |
| 291 | expression analyzer (EXPR) and also output special purpose |
| 292 | operators which will tell PASS2 what to do with the value |
| 293 | represented by the arithmetic expression (e.g., IF, DO). |
| 294 | |
| 295 | 6. After the statement has been processed, control passes to the |
| 296 | end-of-statement routine which handles DO-loop terminations |
| 297 | and then outputs the end-of-statement code. |
| 298 | |
| 299 | 7. Statements containing some kind of error cause a special |
| 300 | error code to be output. |
| 301 | |
| 302 | 8. The entire process is now repeated for the next statement. |
| 303 | |
| 304 | 9. When the END statement is encountered, PASS1 chains to PASS2. |
| 305 | |
| 306 | |
| 307 | |
| 308 | PASS1 SYMBOL TABLE |
| 309 | |
| 310 | A significant portion of the PASS1 processing involves the production |
| 311 | of symbol table entries. These entries contain all storage related |
| 312 | information, i.e., variable name, type, dimensions, etc. |
| 313 | |
| 314 | The symbol table is organized as a set of linked lists. The first 26 |
| 315 | such lists are for variables, with the first letter of the variable |
| 316 | name corresponding to the ordinal number of the list. There are also |
| 317 | separate lists for statement numbers and literals (integer, real, |
| 318 | complex, double, and Hollerith). In addition to list elements, there |
| 319 | are special entries for holding DIMENSION and EQUIVALENCE information. |
| 320 | |
| 321 | A detailed description of each type of entry follows. (NOTE: All |
| 322 | symbol table entries are in Field 1.) |
| 323 | |
| 324 | 1. VARIABLE - The first word of each entry is a pointer to the |
| 325 | next entry, with a zero pointer signaling end of list. The |
| 326 | second word contains type information. The third word points |
| 327 | to the dimension and/or equivalence information blocks. The |
| 328 | next one to three words contain the remainder of the name |
| 329 | (the first character is implied by which list the entry is |
| 330 | in) in stripped six-bit ASCII terminated by a zero character. |
| 331 | Thus, shorter variables take less symbol table space. The |
| 332 | entries are (as for all lists in the symbol table) arranged |
| 333 | in order of increasing magnitude, or alphabetically. |
| 334 | |
| 335 | |
| 336 | |
| 337 | |
| 338 | |
| 339 | |
| 340 | |
| 341 | |
| 342 | |
| 343 | |
| 344 | |
| 345 | 1-2 |
| 346 | \f |
| 347 | |
| 348 | |
| 349 | --------------- |
| 350 | POINTER | ------> | |
| 351 | |-------------| |
| 352 | TYPE | | | | | | | | |
| 353 | |-------------| |
| 354 | DIMENSION/EQUIVALENCE | ------> | |
| 355 | |-------------| |
| 356 | NAME 2-3 | N | A | |
| 357 | |-------------| |
| 358 | NAME 4-5 | M | E | |
| 359 | |-------------| |
| 360 | NAME 6 | X | 0 | |
| 361 | --------------- |
| 362 | |
| 363 | |
| 364 | TYPE WORD FORMAT |
| 365 | |
| 366 | 0 1 2 3 4 5 6 7 8 9 10 11 |
| 367 | ---------------------------------------------------------------------- |
| 368 | | C | D | E | A | E | E || L | A | T || Y | P | E | |
| 369 | | O | I | X | S | Q | X || I | R | || | | | |
| 370 | | M | M | T | F | U | P || T | G | || | | | |
| 371 | | | | | | I | L || | | || | | | |
| 372 | | | | | | V | I || | | || | | | |
| 373 | | | | | | | C || | | || | | | |
| 374 | ---------------------------------------------------------------------- |
| 375 | |
| 376 | BIT |
| 377 | |
| 378 | 0 - Variable is in common. |
| 379 | 1 - Variable is dimensioned. |
| 380 | 2 - External symbol or subroutine/function name. |
| 381 | 3 - Symbol is the name of an arithmetic statement function. |
| 382 | 4 - Variable is an equivalence slave. |
| 383 | 5 - Variable is explicitly typed. |
| 384 | 6 - Entry is a literal. |
| 385 | 7 - Variable is a formal parameter. |
| 386 | |
| 387 | - 1 integer |
| 388 | | 2 real |
| 389 | | 3 complex |
| 390 | 8-11 < 4 double |
| 391 | Type | 5 logical |
| 392 | | 8 statement number |
| 393 | - 9 common section name |
| 394 | |
| 395 | 2. STATEMENT NUMBER - The first two words are the standard |
| 396 | pointer/type. The next three words are the statement number, |
| 397 | with leading zeros deleted, in stripped six-bit ASCII, filled |
| 398 | to the right with blanks. |
| 399 | |
| 400 | |
| 401 | |
| 402 | |
| 403 | |
| 404 | 1-3 |
| 405 | \f |
| 406 | |
| 407 | --------------- |
| 408 | POINTER | ------> | |
| 409 | |-------------| |
| 410 | TYPE | | | | | | | | |
| 411 | |-------------| |
| 412 | NUMBER 1-2 | N | U | |
| 413 | |-------------| |
| 414 | NUMBER 3-4 | M | B | |
| 415 | |-------------| |
| 416 | NUMBER 5 | R | | |
| 417 | --------------- |
| 418 | |
| 419 | 3. INTEGER OR REAL LITERALS - The first two words are the |
| 420 | pointer and type. The next three words are the value in |
| 421 | standard floating-point format (12-bit exponent, 24-bit |
| 422 | signed 2's complement mantissa). Since the type of the |
| 423 | literal must be preserved, there are two lists; hence use of |
| 424 | 1 and 1.0 in the same program will cause one entry in each of |
| 425 | the integer and real literal lists. |
| 426 | |
| 427 | --------------- |
| 428 | POINTER | ------> | |
| 429 | |-------------| |
| 430 | TYPE | | | | | | | | |
| 431 | |-------------| |
| 432 | EXPONENT | V | |
| 433 | |----A--------| |
| 434 | MANTISSA 0-11 | L | |
| 435 | |--------U----| |
| 436 | MANTISSA 12-23 | E | |
| 437 | --------------- |
| 438 | |
| 439 | 4. COMPLEX LITERALS - The first two words are standard. The |
| 440 | next three are the real part in standard floating-point |
| 441 | format. The next three are the imaginary part. |
| 442 | |
| 443 | --------------- |
| 444 | POINTER | ------> | |
| 445 | |-------------| |
| 446 | TYPE | | | | | | | | |
| 447 | |-------------| |
| 448 | REAL EXPONENT | R | |
| 449 | |----E--------| |
| 450 | REAL MANTISSA 0-11 | A | |
| 451 | |------L------| |
| 452 | REAL MANTISSA 12-23 | | |
| 453 | |-------------| |
| 454 | IMAGINARY EXPONENT | IM | |
| 455 | |----A--------| |
| 456 | IMAGINARY MANTISSA 0-11 | GIN | |
| 457 | |--------A----| |
| 458 | IMAGINARY MANTISSA 12-23 | RY | |
| 459 | --------------- |
| 460 | |
| 461 | |
| 462 | |
| 463 | 1-4 |
| 464 | \f |
| 465 | |
| 466 | |
| 467 | 5. DOUBLE PRECISION LITERALS - The first two words are standard. |
| 468 | The next six are the literal in FPP extended format (12-bit |
| 469 | exponent, 60-bit mantissa). |
| 470 | |
| 471 | --------------- |
| 472 | POINTER | ------> | |
| 473 | |-------------| |
| 474 | TYPE | | | | | | | | |
| 475 | |-------------| |
| 476 | EXPONENT | | |
| 477 | |-------------| |
| 478 | MANTISSA 0-11 | | |
| 479 | |-------------| |
| 480 | MANTISSA 12-23 | | |
| 481 | |-------------| |
| 482 | MANTISSA 24-35 | | |
| 483 | |-------------| |
| 484 | MANTISSA 36-47 | | |
| 485 | |-------------| |
| 486 | MANTISSA 48-59 | | |
| 487 | --------------- |
| 488 | |
| 489 | 6. HOLLERITH (quoted) LITERALS - The first two words are stan- |
| 490 | dard. The next N words are the characters of the literal in |
| 491 | stripped six-bit ASCII, ending in a zero character. |
| 492 | |
| 493 | --------------- |
| 494 | POINTER | ------> | |
| 495 | |-------------| |
| 496 | TYPE | | | | | | | | |
| 497 | |-------------| |
| 498 | CHARACTERS 1-2 | | |
| 499 | --------------- |
| 500 | etc. ............. |
| 501 | |
| 502 | |
| 503 | 7. DIMENSION INFORMATION BLOCK - If a variable is DIMENSIONed, |
| 504 | the third word of its symbol table entry will point to its |
| 505 | dimension information block (may be indirectly, see section |
| 506 | 8 below). The first word of this block is the number of |
| 507 | dimensions. The second word is the total size of the array |
| 508 | in elements; thus the size in PDP-8 words may be 3 or 6 times |
| 509 | this number. The third word contains the "magic number" |
| 510 | which is computed as follows: |
| 511 | |
| 512 | n-1 i |
| 513 | MN= - 1+ SUM of d(j) |
| 514 | i=1 j=1 |
| 515 | |
| 516 | where d(j) is the jth dimension and n is the number of |
| 517 | dimensions. |
| 518 | |
| 519 | |
| 520 | |
| 521 | |
| 522 | 1-5 |
| 523 | \f |
| 524 | |
| 525 | |
| 526 | For a 3-dimensional variable this number becomes: |
| 527 | |
| 528 | MN+ 1+d(1)+d(1)d(2) |
| 529 | |
| 530 | The magic number must be subtracted from any computed index, |
| 531 | since indexing starts at one and not zero. The fourth word |
| 532 | will (in PASS2) contain the displacement from #LIT of a |
| 533 | literal which will contain either the magic number in |
| 534 | un-normalized form (for dimensioned variables which are |
| 535 | subroutine arguments) or the address of the variable minus |
| 536 | the magic number (for local or COMMON dimensioned variables). |
| 537 | This literal is necessary for calling subroutines where a |
| 538 | subscripted variable is an argument. The next N words are |
| 539 | the dimensions of the variable. If the variable is a formal |
| 540 | parameter of the subroutine, it may have one or more dimen- |
| 541 | sions which are also formal parameters. In this case, the |
| 542 | magic number is zero, and the dimension(s) is a pointer to |
| 543 | the symbol table entry for the variable(s) used as a dimen- |
| 544 | sion. |
| 545 | |
| 546 | ---------- |
| 547 | NUMBER OF DIMENSIONS | # | |
| 548 | |--------| |
| 549 | TOTAL NUMBER OF ELEMENTS | SIZE | |
| 550 | |--------| |
| 551 | MAGIC NUMBER | MN | |
| 552 | |--------| |
| 553 | RESERVED | | |
| 554 | |--------| |
| 555 | DIMENSION 1 | D1 | |
| 556 | |--------| |
| 557 | DIMENSION 2 | D2 | |
| 558 | ---------- |
| 559 | ........ |
| 560 | ---------- |
| 561 | DIMENSION n | Dn | |
| 562 | ---------- |
| 563 | |
| 564 | 8. EQUIVALENCE INFORMATION BLOCK - If a variable is an |
| 565 | EQUIVALENCE slave variable, the third word of its symbol |
| 566 | table entry points to the equivalence information block. |
| 567 | The first word of this block points to the dimension infor- |
| 568 | mation (if any) of the variable. The second word points to |
| 569 | the symbol table entry of the EQUIVALENCE master variable. |
| 570 | The third word is the linearized subscript of the master |
| 571 | variable from the EQUIVALENCE statement. The fourth word is |
| 572 | the linearized subscript of the slave variable. |
| 573 | |
| 574 | |
| 575 | |
| 576 | |
| 577 | |
| 578 | |
| 579 | |
| 580 | |
| 581 | 1-6 |
| 582 | \f |
| 583 | |
| 584 | |
| 585 | --------------- |
| 586 | POINTER TO DIMENSIONS | ------> | |
| 587 | |-------------| |
| 588 | POINTER TO MASTER | ------> | |
| 589 | |-------------| |
| 590 | MASTER SUBSCRIPT | SSM | |
| 591 | |-------------| |
| 592 | SLAVE SUBSCRIPT | SSM | |
| 593 | --------------- |
| 594 | |
| 595 | 9. COMMON INFORMATION BLOCK - If a symbol is defined as the name |
| 596 | of a COMMON section, the third word of its symbol table entry |
| 597 | points to a list of common information blocks. The first |
| 598 | word of each such block points to the next block. The second |
| 599 | word is the number of entries in the list that follows. The |
| 600 | rest of the block is a set of pointers to the symbol table |
| 601 | entries of the variables in the COMMON section. |
| 602 | |
| 603 | --------------- |
| 604 | POINTER TO NEXT CIB | ------> | |
| 605 | |-------------| |
| 606 | NUMBER OF ENTRIES | # | |
| 607 | |-------------| |
| 608 | - | ------> | |
| 609 | | |-------------| |
| 610 | POINTER TO VARIABLES < | ------> | |
| 611 | IN THIS COMMON | |-------------| |
| 612 | - | ------> | |
| 613 | --------------- |
| 614 | |
| 615 | |
| 616 | |
| 617 | PASS1 OUTPUT |
| 618 | |
| 619 | The output of PASS1 is a stream of polish with many special operators. |
| 620 | Whenever an operand is to be output, the address of its symbol table |
| 621 | entry is used. The following is a list of the output codes (in their |
| 622 | mnemonic form, obtain numeric values from listing of PASS1) and the |
| 623 | operation they are conveying to PASS2: |
| 624 | |
| 625 | PUSH The next word in the output file is an operand |
| 626 | (symbol table pointer) to be put onto the stack. |
| 627 | |
| 628 | ADD Add the operands represented by the top two stack |
| 629 | entries (actually this causes PASS2 to generate |
| 630 | the RALF coding which will do the desired add). |
| 631 | |
| 632 | SUB Subtract top from next-to-top. |
| 633 | |
| 634 | MUL Multiply top two. |
| 635 | |
| 636 | DIV Divide top into next-to-top. |
| 637 | |
| 638 | EXP Raise next-to-top to power of top. |
| 639 | |
| 640 | 1-7 |
| 641 | \f |
| 642 | |
| 643 | |
| 644 | NOT Logical .NOT. of top of stack. |
| 645 | |
| 646 | NEG Negate top of stack. |
| 647 | |
| 648 | GE Compare top two for greater than or equal to, this |
| 649 | has TRUE value if the next-to-top is .GE. the top. |
| 650 | |
| 651 | GT Compare for greater than. |
| 652 | |
| 653 | LE Compare for less than or equal. |
| 654 | |
| 655 | LT Compare for less than. |
| 656 | |
| 657 | AND Logical AND of top two entries. |
| 658 | |
| 659 | OR Logical inclusive OR of top two. |
| 660 | |
| 661 | EQ Compare top two for equality. |
| 662 | |
| 663 | NE Compare top two for inequality. |
| 664 | |
| 665 | XOR Exclusive OR of top two. |
| 666 | |
| 667 | EQV EQUIVALENCE of top two. |
| 668 | |
| 669 | PAUSOP Use top of stack as PAUSE number. |
| 670 | |
| 671 | DPUSH The next two words are a symbol table pointer and |
| 672 | a displacement; put them onto the stack (used for |
| 673 | DATA statements). |
| 674 | |
| 675 | BINRD1 Take the top of stack as the unit number and com- |
| 676 | pile an unformatted READ-open. |
| 677 | |
| 678 | FMTRD1 The top two stack elements are the unit and |
| 679 | format, take them and compile a formatted READ- |
| 680 | open. |
| 681 | |
| 682 | RCLOSE Compile a READ-close. |
| 683 | |
| 684 | DARD1 Take the top two stack elements as a unit number |
| 685 | and a block number and compile a direct access |
| 686 | unformatted READ-open. |
| 687 | BINWR1 - |
| 688 | FMTWRI |> Same as for the corresponding READ case, except |
| 689 | WCLOSE | substitute the word "WRITE". |
| 690 | DAWR1 - |
| 691 | |
| 692 | DEFFIL Take the top four stack entries as the unit, |
| 693 | number of records, record size, and index |
| 694 | variable and compile a DEFINE FILE call. |
| 695 | |
| 696 | ASFDEF Set the PASS2 switch which says that the following |
| 697 | statement is an arithmetic statement function. |
| 698 | |
| 699 | 1-8 |
| 700 | \f |
| 701 | |
| 702 | |
| 703 | ARGSOP The next word is a count, call it n; take the |
| 704 | previous n stack entries as subscripts (or |
| 705 | arguments) and the N+1st entry from the top as |
| 706 | the array (or function) name; now compile this |
| 707 | as an array reference (or function/subroutine |
| 708 | call). |
| 709 | |
| 710 | EOLCOD The current statement is completed, reset stacks |
| 711 | and do other housekeeping. |
| 712 | |
| 713 | ERRCOD The following word contains an error code, write |
| 714 | it on the TTY together with the current line |
| 715 | number, and put the error code and line number |
| 716 | into the error list for possible PASS3. |
| 717 | |
| 718 | RETOPR Compile a subroutine RETURN. |
| 719 | |
| 720 | REWOPR Take the top of stack as a unit and compile a |
| 721 | rewind. |
| 722 | |
| 723 | STOROP Compile a store of the top of stack into the |
| 724 | next-to-top. |
| 725 | |
| 726 | ENDOPR Compile a RETURN if a function or subroutine or |
| 727 | a CALL EXIT if a main program. |
| 728 | |
| 729 | DEFLBL The following word is a symbol table pointer to |
| 730 | a statement number, compile this as the tag for |
| 731 | the current RALF line. |
| 732 | |
| 733 | DOFINI The following word is a symbol table pointer for |
| 734 | the DO-loop index, compile the corresponding |
| 735 | DO-ending code. |
| 736 | |
| 737 | ARTHIF The following one, two, or three words are symbol |
| 738 | table pointers to statement numbers for the less |
| 739 | than zero, zero, and greater than zero conditions |
| 740 | with the comparison to be made on the top of |
| 741 | stack. |
| 742 | |
| 743 | LIFBGN The top of stack is taken as a logical expression |
| 744 | PASS 2 should compile a jump-around-on-false; this |
| 745 | implies that some statement is to follow. |
| 746 | |
| 747 | DOBEGN The top two stack entries represent the final |
| 748 | value and increment of the DO-loop, process them |
| 749 | in hopes of finding a matching DOFINI. |
| 750 | |
| 751 | ENDFOP The top of stack is a unit, compile an END FILE. |
| 752 | |
| 753 | STOPOP Compile a CALL EXIT. |
| 754 | |
| 755 | |
| 756 | |
| 757 | |
| 758 | 1-9 |
| 759 | \f |
| 760 | |
| 761 | |
| 762 | ASNOPR The next word is the address of the symbol table |
| 763 | entry for a statement number; compile an ASSIGN |
| 764 | of this statement number to the variable |
| 765 | represented by the top of stack. |
| 766 | |
| 767 | BAKOPR Take the top of stack as the unit and compile |
| 768 | a BACKSPACE. |
| 769 | |
| 770 | FMTOPR The following word is a count N; the next N words |
| 771 | after that are the image of the FORMAT statement. |
| 772 | |
| 773 | GO2OPR The following word is the symbol table entry for |
| 774 | the statement number which is to be executed next. |
| 775 | |
| 776 | CGO2OP The following word is a count N; the next N words |
| 777 | are symbol table pointers for the statement |
| 778 | numbers of a computed GO TO list; use the value |
| 779 | represented by the top of stack to compile a |
| 780 | computed GO TO into this list. |
| 781 | |
| 782 | AGO2OP Compile an assigned GO TO with the top of stack. |
| 783 | |
| 784 | IOLMNT Take the top of stack as a list element for an |
| 785 | I/O statement and compile read or write; PASS2 |
| 786 | knows if it is a READ or WRITE by remembering |
| 787 | previous FMTRD1, FMTWR1, etc. |
| 788 | |
| 789 | DATELM The next word is a count N; the next N words are |
| 790 | a data element. |
| 791 | |
| 792 | DREPTC The next word is a repetition count for the set |
| 793 | of DATELMs up until the next ENDELM. |
| 794 | |
| 795 | ENDELM Signals the end of a data element group. |
| 796 | |
| 797 | PRGSTK Tells PASS2 to purge the top stack entry. |
| 798 | |
| 799 | DOSTOR Performs the same function as STOROP after |
| 800 | checking the top two stack elements for legal |
| 801 | DO-parameter type (integer or real). |
| 802 | |
| 803 | |
| 804 | |
| 805 | PASS 1 SUBROUTINES |
| 806 | |
| 807 | The following is a brief description of the function of each of the |
| 808 | major PASS1 subroutines: |
| 809 | |
| 810 | RDWR Compiles everything in a READ or WRITE statement |
| 811 | starting at the first left parenthesis. |
| 812 | |
| 813 | RESTCP Restore character pointer and count for the |
| 814 | statement buffer from the stack. |
| 815 | |
| 816 | |
| 817 | 1-10 |
| 818 | \f |
| 819 | |
| 820 | |
| 821 | OUTWRD Output a word (the AC on entering) to the PASS1 |
| 822 | output file. |
| 823 | |
| 824 | COMARP Test for comma or right parenthesis, skip one |
| 825 | instruction if a comma, two if a right |
| 826 | parenthesis, and none if neither. |
| 827 | |
| 828 | BACK1 Backup the statement buffer character pointer. |
| 829 | |
| 830 | GETSS Scans a variable reference, or subscripted |
| 831 | variable reference with numeric subscripts and |
| 832 | returns the linearized subscript. |
| 833 | |
| 834 | MUL12 Perform a 12-bit unsigned integer multiply. |
| 835 | |
| 836 | DOSTUF Handles compilation of DO-loop setup. |
| 837 | |
| 838 | TYPLST Process a type declaration, DIMENSION, or |
| 839 | COMMON statement; sets up type bits and/or |
| 840 | dimension information. |
| 841 | |
| 842 | LOOKUP Perform a symbol table search for variables and |
| 843 | Hollerith literals. |
| 844 | |
| 845 | LUKUP2 Perform a symbol table search for integer, real, |
| 846 | complex, and double precision literals or |
| 847 | statement numbers. |
| 848 | |
| 849 | EXPR Analyze and process an arithmetic expression. |
| 850 | |
| 851 | LETTER Get next character from the statement buffer and |
| 852 | skip if it is a letter, otherwise put the |
| 853 | character back and don't skip. |
| 854 | |
| 855 | CHECKC The first word after the JMS is the negative of |
| 856 | the ASCII character to test for; if this is the |
| 857 | next character, skip. |
| 858 | |
| 859 | GETCWB Get the next character from the statement buffer |
| 860 | preserving blanks. |
| 861 | |
| 862 | SAVECP Save the character pointer and count on the stack. |
| 863 | |
| 864 | GETC Get the next character ignoring blanks. |
| 865 | |
| 866 | ERMSG Output an error code to PASS1 output file. |
| 867 | |
| 868 | POP Pop the stack into the AC. |
| 869 | |
| 870 | PUSH Push the AC onto the stack. |
| 871 | |
| 872 | LEXPR Analyze and process an arithmetic expression, |
| 873 | legal to the left of the equal sign in an |
| 874 | assignment statement. |
| 875 | |
| 876 | 1-11 |
| 877 | \f |
| 878 | |
| 879 | GET2C Get the next two character into one word. |
| 880 | |
| 881 | STMNUM Scan off a statement number and do the symbol |
| 882 | table search. |
| 883 | |
| 884 | DIGIT Same as letter, except checks for a digit. |
| 885 | |
| 886 | NUMBER Scans off an integer, real, or double precision |
| 887 | literal. |
| 888 | |
| 889 | GETNAM Scan off a variable name. |
| 890 | |
| 891 | ICHAR Get the next character from the input file. |
| 892 | |
| 893 | |
| 894 | |
| 895 | PASS2 OPERATION |
| 896 | |
| 897 | The first part of PASS2 generates the storage for variables, |
| 898 | arguments, arrays, literals and temporaries by processing the symbol |
| 899 | table built by PASS1, which is kept in core. The next step is to |
| 900 | generate the code for subroutine entry and exit including argument |
| 901 | pickup and restore. After all such prolog code is generated, PASS2O |
| 902 | is loaded into core, overlaying most of the prolog-generating |
| 903 | functions. The main loop of the compiler is now entered. This |
| 904 | consists simply of reading a PASS1 output code from the intermediate |
| 905 | file and using this number as an index into a jump table. The |
| 906 | sections of code entered in this way then perform the correct |
| 907 | generation of RALF code. |
| 908 | |
| 909 | Example: |
| 910 | |
| 911 | The statement: A=B+C*D |
| 912 | would produce the following PASS1 output: |
| 913 | (assuming A,B,C,D are REAL) |
| 914 | |
| 915 | 1) PUSH |
| 916 | ->A (symbol table address of A) |
| 917 | |
| 918 | 2) PUSH |
| 919 | ->B |
| 920 | |
| 921 | 3) PUSH |
| 922 | ->C |
| 923 | |
| 924 | 4) PUSH |
| 925 | ->D |
| 926 | |
| 927 | 5) MUL |
| 928 | |
| 929 | 6) ADD |
| 930 | |
| 931 | 7) STOROP |
| 932 | |
| 933 | 8) EOLCOD |
| 934 | |
| 935 | 1-12 |
| 936 | \f |
| 937 | |
| 938 | |
| 939 | The corresponding operations performed by PASS2 are: |
| 940 | |
| 941 | 1) Make a 3-word entry on the stack corresponding to the |
| 942 | variable A consisting of a pointer to the symbol table |
| 943 | entry, a word containing the type, and one reserved word. |
| 944 | |
| 945 | 2) Repeat above for B. |
| 946 | |
| 947 | 3) Repeat above for C. |
| 948 | |
| 949 | 4) Repeat above for D. |
| 950 | |
| 951 | 5) The multiply operator is handled like any of the binary |
| 952 | operators by the subroutine CODE. This routine is called |
| 953 | with the address of the multiply skeleton table. The |
| 954 | top two stack entries are taken as the operands, with |
| 955 | their types used to index into the skeleton tables. |
| 956 | (See description of binary operator skeleton tables below.) |
| 957 | The correct skeleton for this combination is chosen based on |
| 958 | the where-abouts of each of the operands (AC or memory) |
| 959 | at the corresponding point in the code which is being |
| 960 | compiled. There are three possible cases: Memory,AC; |
| 961 | Memory,Memory; AC,Memory. In this example, both operands |
| 962 | are in memory so the code generated would be: |
| 963 | |
| 964 | FLDA C |
| 965 | |
| 966 | FMUL D |
| 967 | |
| 968 | The CODE subroutine then makes a new stack entry to replace |
| 969 | the entries for C and D. This entry has a 0 in place of |
| 970 | the symbol table pointer, signifying that the operand is in |
| 971 | the AC. Other special case operand codes are: |
| 972 | |
| 973 | 0 - AC ( Already mentioned) |
| 974 | |
| 975 | 1 - 51 Temporaries |
| 976 | |
| 977 | 52 - 60 Array reference, the subscript of which is in |
| 978 | an index register (1-7). |
| 979 | |
| 980 | 61 - A variable, the address of which is in base |
| 981 | location 0. |
| 982 | |
| 983 | 62 - A variable, the address of which is in base |
| 984 | location 3. |
| 985 | |
| 986 | 63-6777 - Symbol table entry (can be variable or |
| 987 | literal). |
| 988 | |
| 989 | 7000 - Special temporary |
| 990 | |
| 991 | |
| 992 | |
| 993 | |
| 994 | 1-13 |
| 995 | \f |
| 996 | |
| 997 | |
| 998 | 6) The add operator is handled in the same way as for multiply, |
| 999 | except that in this case the add skeleton table is used. |
| 1000 | When the correct row is found, the memory,AC case is chosen |
| 1001 | since the result of C*D is now in the AC. This skeleton |
| 1002 | simply generates: |
| 1003 | |
| 1004 | FADD B |
| 1005 | |
| 1006 | The new top of stack entry is a 0, since the result is in |
| 1007 | the AC. |
| 1008 | |
| 1009 | 7) The store operation works in a similar manner using a special |
| 1010 | skeleton table to determine whether the value to be stored is |
| 1011 | already in the AC and whether it must be converted from one |
| 1012 | type to another. In this case, no conversion need be |
| 1013 | performed and the code generated is: |
| 1014 | |
| 1015 | FSTA A |
| 1016 | |
| 1017 | 8) The end of statement has been reached and any necessary |
| 1018 | bookkeeping is performed. |
| 1019 | |
| 1020 | |
| 1021 | |
| 1022 | PASS2 SYMBOL TABLE |
| 1023 | |
| 1024 | PASS2 modifies the symbol table entries corresponding to variables |
| 1025 | by replacing the first word of the entry with the first character of |
| 1026 | the name, this character being derived from the list in which the name |
| 1027 | is located. |
| 1028 | |
| 1029 | |
| 1030 | |
| 1031 | PASS2 ERROR LIST |
| 1032 | |
| 1033 | PASS2 creates a list (in field 1) of error codes and line numbers |
| 1034 | corresponding to the errors printed on the Teletype during PASS2. |
| 1035 | This list works downward starting just below the skeleton table area, |
| 1036 | working towards the symbol table area. PASS3 uses this list to |
| 1037 | write out extended error messages on the listing. |
| 1038 | |
| 1039 | |
| 1040 | |
| 1041 | PASS2 SKELETON TABLES |
| 1042 | |
| 1043 | All binary operators have associated with them a skeleton table |
| 1044 | having 24 entries arranged in 8 rows and 3 columns. The rows |
| 1045 | correspond to the following eight possibilities: |
| 1046 | |
| 1047 | 1) Both operands integer or real. |
| 1048 | 2) Both operands complex. |
| 1049 | 3) Both operands double precision. |
| 1050 | 4) First operand integer or real, second complex. |
| 1051 | 5) First operand integer or real, second double precision. |
| 1052 | |
| 1053 | 1-14 |
| 1054 | \f |
| 1055 | |
| 1056 | |
| 1057 | 6) First operand complex, second integer or real. |
| 1058 | 7) First operand double precision, second integer or real. |
| 1059 | 8) Both operands logical. |
| 1060 | |
| 1061 | The columns correspond to the following three possibilities: |
| 1062 | |
| 1063 | 1) First operand in memory, second in AC. |
| 1064 | 2) Both operands in memory. |
| 1065 | 3) First operand in the AC, second in memory. |
| 1066 | |
| 1067 | Each entry of the skeleton tables is either zero (illegal operator- |
| 1068 | type combination) or points to a code skeleton (minus one). Code |
| 1069 | skeletons are composed of combinations of the following types of |
| 1070 | elements: |
| 1071 | |
| 1072 | 1) OPCODES - If an element has a non-negative value, it is taken |
| 1073 | as the address of a text string for the desired opcode. This |
| 1074 | works since all such text strings are stored below location |
| 1075 | 4000 (in field 0). In this case, the next word of the |
| 1076 | skeleton is taken as a designator for the address field, the |
| 1077 | possibilities are: |
| 1078 | |
| 1079 | a. A non-negative values means the address field is a |
| 1080 | literal text string, with the value being the address of |
| 1081 | the string. (Same restriction as for opcode text |
| 1082 | strings.) |
| 1083 | |
| 1084 | b. A zero indicates that this instruction should have no |
| 1085 | address field. |
| 1086 | |
| 1087 | c. A minus one indicates that the address field is the |
| 1088 | operand defined by the three variables ARG1, TYPE1, and |
| 1089 | BASE1. |
| 1090 | |
| 1091 | d. A minus two indicates that the address field is the |
| 1092 | operand defined by the three variables ARG2, TYPE2, and |
| 1093 | BASE2. |
| 1094 | |
| 1095 | 2) MODE CHANGE - An element value of minus one means generate a |
| 1096 | STARTF if currently in extended mode. A value of minus two |
| 1097 | means generate a STARTE if currently in single mode. |
| 1098 | |
| 1099 | 3) MACRO - Any other negative value is taken as the address |
| 1100 | (minus 3) of a sub-skeleton. This sub-skeleton may contain |
| 1101 | anything except another sub-skeleton reference. When the |
| 1102 | end of the sub-skeleton is encountered, the main skeleton is |
| 1103 | re-entered. |
| 1104 | |
| 1105 | 4) END-OF-SKELETON - A zero indicates the end of the skeleton. |
| 1106 | |
| 1107 | |
| 1108 | |
| 1109 | |
| 1110 | |
| 1111 | |
| 1112 | 1-15 |
| 1113 | \f |
| 1114 | |
| 1115 | |
| 1116 | PASS2 SUBROUTINES |
| 1117 | |
| 1118 | The following is a list of the major PASS 2 subroutines together with |
| 1119 | a brief functional description. |
| 1120 | |
| 1121 | ERMSG Output a 2-character error code together with the |
| 1122 | line number on the Teletypes; also put the code and |
| 1123 | line number into the error list for PASS3. |
| 1124 | |
| 1125 | UCODE Generate the code for unary operators, given the |
| 1126 | skeleton table address. |
| 1127 | |
| 1128 | CODE Generate code for binary operators, given the |
| 1129 | skeleton table address. |
| 1130 | |
| 1131 | INWORD Read a word from the PASS1 output file. |
| 1132 | |
| 1133 | FATAL Output a fatal error message and exit to OS/8. |
| 1134 | |
| 1135 | ONUMBER Output the AC as a 4-digit octal number. |
| 1136 | |
| 1137 | SAVEAC Generate an FSTA #TMP+XXXX if necessary. |
| 1138 | |
| 1139 | GENCOD Generate the code specified by the given code |
| 1140 | skeleton. |
| 1141 | |
| 1142 | OPCOD Output a TAB followed by the specified opcode |
| 1143 | field. |
| 1144 | |
| 1145 | OPCODE Same as OPCOD, except output a second TAB after |
| 1146 | the opcode field. |
| 1147 | |
| 1148 | OADDR Generate the address field specified by the |
| 1149 | argument. |
| 1150 | |
| 1151 | GENSTF Generate STARTF if in E mode. |
| 1152 | |
| 1153 | GENSTE Generate STARTE if in F mode. |
| 1154 | |
| 1155 | OSNUM Output a statement number preceded by a "#". |
| 1156 | |
| 1157 | CRLF Output a carriage return/line feed. |
| 1158 | |
| 1159 | OTAB Output a TAB. |
| 1160 | |
| 1161 | OUTSYM Output a text string. |
| 1162 | |
| 1163 | GARG Pop the top entry of the stack into ARG1, TYPE1, |
| 1164 | and BASE1. |
| 1165 | |
| 1166 | GARGS Pop the top two stack entries into ARG1, TYPE1, |
| 1167 | BASE1 and ARG2, TYPE2, BASE2. |
| 1168 | |
| 1169 | OUTNAM Output a variable name. |
| 1170 | |
| 1171 | 1-16 |
| 1172 | \f |
| 1173 | |
| 1174 | |
| 1175 | OLABEL Output a generated label. |
| 1176 | |
| 1177 | GETSS Find the address of the dimension information |
| 1178 | block given the symbol table address. |
| 1179 | |
| 1180 | SKPIRL Skip if integer, real, or logical. |
| 1181 | |
| 1182 | GENCAL Generate the code for a subroutine call from |
| 1183 | the information contained on the stack. |
| 1184 | |
| 1185 | MUL12 Do a 12-bit unsigned multiply. |
| 1186 | |
| 1187 | OINS Output a literal opcode and address field. |
| 1188 | |
| 1189 | OCHAR Output a character |
| 1190 | |
| 1191 | NUMBRO Output a 5-digit octal number. |
| 1192 | |
| 1193 | |
| 1194 | |
| 1195 | PASS3 OPERATION |
| 1196 | |
| 1197 | PASS3 first initializes the listing header line with the version |
| 1198 | number, date, and page number. It then processes lines, much like |
| 1199 | PASS1, handling continuations and comments and outputs their image |
| 1200 | to the listing file together with the line number. A constant check |
| 1201 | is made on the error message list for line numbers that correspond |
| 1202 | to the current line number, When such a correspondence occurs, the |
| 1203 | error code is used to find the associated detailed error message, |
| 1204 | which is then printed out. |
| 1205 | |
| 1206 | |
| 1207 | |
| 1208 | |
| 1209 | |
| 1210 | |
| 1211 | |
| 1212 | |
| 1213 | |
| 1214 | |
| 1215 | |
| 1216 | |
| 1217 | |
| 1218 | |
| 1219 | |
| 1220 | |
| 1221 | |
| 1222 | |
| 1223 | |
| 1224 | |
| 1225 | |
| 1226 | |
| 1227 | |
| 1228 | |
| 1229 | |
| 1230 | 1-17 |
| 1231 | \f |
| 1232 | |
| 1233 | |
| 1234 | CHAPTER 2 |
| 1235 | |
| 1236 | THE RALF ASSEMBLER |
| 1237 | |
| 1238 | |
| 1239 | RALF and FLAP are essentially the same program, with differences con- |
| 1240 | trolled by the conditional assembly parameter RALF, which must be |
| 1241 | nonzero to assemble RALF, or zero to assemble FLAP. The source may be |
| 1242 | assembled by either PAL8 or FLAP; although FLAP flags one error (a US |
| 1243 | on a FIELD statement), this may safely be ignored. The remainder of |
| 1244 | this chapter applies to RALF only. The following definitions are pre- |
| 1245 | requisite to discussion of the operation of this assembler. |
| 1246 | |
| 1247 | MODULE The relocatable binary output of an assembly. A module |
| 1248 | is physically an OS/8 file or sub-file in a library, |
| 1249 | and is made up of an external symbol dictionary and |
| 1250 | related text. Logically, it consists of one or more |
| 1251 | program sections and COMMON sections. |
| 1252 | |
| 1253 | LIBRARY An OS/8 file on a directory device containing a catalog |
| 1254 | and one or more modules as sub-files. Used solely by |
| 1255 | the loader, as a source of modules with which to |
| 1256 | satisfy unresolved symbols in a program being loaded. |
| 1257 | |
| 1258 | CATALOG A list of entry points defined in modules contained in |
| 1259 | a library, with an indication of the locations of the |
| 1260 | modules which define them. |
| 1261 | |
| 1262 | EXTERNAL A list of the global symbols defined in and/or used by |
| 1263 | SYMBOL a module. Usually called ESD table. |
| 1264 | DICTIONARY |
| 1265 | |
| 1266 | TEXT That part of the assembler's binary output which |
| 1267 | contains the binary data to be loaded into memory, |
| 1268 | along with sufficient information for the loader to |
| 1269 | associate the output with specific memory locations |
| 1270 | through references to the ESD table. |
| 1271 | |
| 1272 | SECTION A unit of binary data output by the assembler as part |
| 1273 | of a module to be loaded into a contiguous area of |
| 1274 | memory. COMMON sections are a special case in that |
| 1275 | they may be defined with the same name in each of many |
| 1276 | modules. In this case, all the definitions are combined |
| 1277 | to create a single section in memory whose size is that |
| 1278 | of the largest COMMON section with the given name. |
| 1279 | Program sections, the only other type of section, must |
| 1280 | have unique names. Sections are listed in the ESD |
| 1281 | table by name, type and size. |
| 1282 | |
| 1283 | ENTRY POINT An address within a section which is named and defined |
| 1284 | to be global, so that it may be used for the resolution |
| 1285 | of external references in other sections. Entry points |
| 1286 | are listed in the ESD table by name, type and address |
| 1287 | within the section in which they occur. |
| 1288 | |
| 1289 | 2-1 |
| 1290 | \f |
| 1291 | |
| 1292 | |
| 1293 | EXTERNAL A symbol which is specified at assembly time to be |
| 1294 | SYMBOL defined in another module as an entry point. External |
| 1295 | symbols are listed in the ESD table by name and type. |
| 1296 | A complete program must include entry point names |
| 1297 | equivalent to every external symbol defined in every |
| 1298 | module in the program. There need not, however, be an |
| 1299 | external symbol for every entry point, nor is there any |
| 1300 | limit on the number of modules which may contain |
| 1301 | external symbols referencing one entry point. From a |
| 1302 | functional viewpoint, entry points correspond to tags |
| 1303 | within a program and external symbols correspond to |
| 1304 | references to those tags. Every section is considered |
| 1305 | to have an entry point at location zero of the section. |
| 1306 | The name of this entry point is the section name. |
| 1307 | |
| 1308 | When RALF is called from the monitor, execution begins at the tag |
| 1309 | BEGIN. Unless entry is via CHAIN, the OS/8 command decoder is called |
| 1310 | to obtain input and output file designations. If entry is by way of |
| 1311 | CHAIN, it is assumed that the command decoder area has already been |
| 1312 | set up by the caller. In either case, it is always assumed that the |
| 1313 | USR is already in core. A check is made to determine that the first |
| 1314 | output file is a directory device file and, if no first output file |
| 1315 | was specified, the default file SYS:FORTRN.RL is set up. |
| 1316 | |
| 1317 | Default output file extensions are defined if none were specified to |
| 1318 | the command decoder, using .RL for the first output file and .LS for |
| 1319 | the second output file. The first output file is then opened, and the |
| 1320 | handler for the first input file is FETCHed. If /L or /G was |
| 1321 | specified, the loader is looked up on SYS so that chaining will be |
| 1322 | possible. The symbol table, which is loaded above 12000 in order to |
| 1323 | preserve the USR, is now moved down to 10000. Finally, the system |
| 1324 | date word is converted to character form and stored in the title |
| 1325 | buffer. This completes the initialization procedure, and control is |
| 1326 | passed to NEWLIN to collect the first line in the buffer. |
| 1327 | |
| 1328 | At NEXTST, teats are made to determine whether the line just assembled |
| 1329 | needs to be listed, and whether there are any remaining significant |
| 1330 | characters in the line which have not been assembled. If a semicolon |
| 1331 | terminated the statement, the character pointers are bumped to skip |
| 1332 | over it, and control passes to ASMBL to process the next statement on |
| 1333 | the line. If the assembler is currently in a REPEAT line and the |
| 1334 | count is not exhausted, the current line is re-assembled. Otherwise, |
| 1335 | a new line is obtained in the line buffer by collecting input |
| 1336 | characters until a carriage return is found. If the line is longer |
| 1337 | than 128 characters, all characters after the 128th are ignored and |
| 1338 | the LT message is printed. The line length is calculated and saved. |
| 1339 | |
| 1340 | At ASMBL, ASMOF is tested to determine whether the assembly is |
| 1341 | currently inside a conditional. If so, the line is scanned for angle |
| 1342 | brackets but not assembled. If not, and the first character is not a |
| 1343 | slash, leading blanks are thrown away and control passes to LUNAME. |
| 1344 | If there is a name, it is collected. If it is followed by a comma, |
| 1345 | the symbol is looked up in the user symbol table. If the symbol is |
| 1346 | undefined, it is defined as a label. If it was already defined, the |
| 1347 | |
| 1348 | 2-2 |
| 1349 | \f |
| 1350 | |
| 1351 | |
| 1352 | current location counter is compared with it to check for a possible |
| 1353 | MD error. Control then returns to ASMBL. |
| 1354 | |
| 1355 | If the symbol found by LUNAME was followed by an equal sign, it is |
| 1356 | looked up and defined according to the expression to the right of the |
| 1357 | equal sign. If it was followed by a space, either of the characters |
| 1358 | ' or #, or the character % and then a space, it is looked up in the |
| 1359 | op-code table. If it is found, control passes to the appropriate |
| 1360 | op-code handler. Otherwise, control is dispatched to GETEXP which |
| 1361 | restores the character pointers saved by LUNAME, processes the rest of |
| 1362 | the line as a single-word expression, and returns to NEXTST for the |
| 1363 | next statement. |
| 1364 | |
| 1365 | Expressions are processed on a strict left-to-right basis by the |
| 1366 | routine EXPR. A symbol is looked up, and its value is stored in WORD1 |
| 1367 | and WORD2. It is then combined with the accumulated expressions in |
| 1368 | EXPVAL according to the operator in LASTOP. A new operator (if any) |
| 1369 | is then located, and the loop begins again. When no operator is found |
| 1370 | after some symbol, the expression is considered complete and control |
| 1371 | returns to the calling routine. Undefined symbols appearing in an |
| 1372 | expression cause output of a US message, and the value zero is used |
| 1373 | in their place. COMMON and section names in the symbol table have |
| 1374 | special values (namely their lengths), but they always refer to the |
| 1375 | starting location of the sections they define, and their values are |
| 1376 | taken to be zero of the section so named. If GETNAM is not able to |
| 1377 | find a symbol in the expression, three possibilities are checked |
| 1378 | before flagging the expression as invalid: |
| 1379 | |
| 1380 | 1. It may be a number, rather than a symbol. |
| 1381 | |
| 1382 | 2. It may be one of the characters period (representing the |
| 1383 | current value of the location counter) or double quote |
| 1384 | (representing the binary value of the next ASCII character). |
| 1385 | |
| 1386 | 3. The last operator may have been a plus sign in an indexed FPP |
| 1387 | instruction. |
| 1388 | |
| 1389 | At the end of expression evaluation, the console keyboard flag is |
| 1390 | checked to ensure that the user has not typed CTRL/C to stop the |
| 1391 | assembly. |
| 1392 | |
| 1393 | There are six expression operator routines, one each for the |
| 1394 | operations add, subtract, AND, OR, multiply and divide. Except for |
| 1395 | add and subtract, these routines must operate on absolute addresses |
| 1396 | because the loader does not have facilities for non-additive |
| 1397 | resolution of address constants. |
| 1398 | |
| 1399 | The symbol table is the sole occupant of field 1, except for the OS/8 |
| 1400 | field 1 resident. The symbol table is loaded at location 12000 to |
| 1401 | prevent an unnecessary swap of the USR, but moved down, to start at |
| 1402 | location 10000, during initialization. Subsequent calls to the USR do |
| 1403 | require a swap. The symbol table is a set of linked lists, or, more |
| 1404 | properly, two sets; one for user-defined symbols and one for op-codes |
| 1405 | and pseudo-ops. Each set contains a list corresponding to every |
| 1406 | |
| 1407 | 2-3 |
| 1408 | \f |
| 1409 | |
| 1410 | |
| 1411 | letter of the alphabet, and each list consists of the symbols which |
| 1412 | start with that same letter. Every time a symbol is encountered in |
| 1413 | the source, the list corresponding to its first letter is searched |
| 1414 | until a match is found, or until the end of the list or a symbol of |
| 1415 | higher alphabetical order is found. In the latter cases, the new |
| 1416 | symbol is inserted into the user symbol table by changing the list |
| 1417 | pointers so that the new symbol appears in the list in correct |
| 1418 | alphabetical order. The pre-defined symbol table is never changed, |
| 1419 | because the user is not permitted to define op-codes or pseudo-ops. |
| 1420 | |
| 1421 | A RALF output file of relocatable binary data consists of two parts; |
| 1422 | the ESD table and the text. The ESD table contains all information |
| 1423 | required by LIBRA or the loader, and is generated between the first |
| 1424 | and second passes of assembly. It serves as a partial symbol table |
| 1425 | for the loader (the full symbol table is built up from the ESD tables |
| 1426 | of all the modules in a program) and provides the name, attributes, |
| 1427 | and value of every global symbol used by any module, as well as an ESD |
| 1428 | code by which the symbol may be referred to within the text. Every |
| 1429 | entry in the ESD table is six words long. The first three words are |
| 1430 | the symbol itself, packed in stripped ASCII, with two characters per |
| 1431 | word. The next word contains type information in the following |
| 1432 | format: |
| 1433 | |
| 1434 | A VALUE OF INDICATES |
| 1435 | |
| 1436 | 0 Last entry in the ESD table. |
| 1437 | |
| 1438 | 1 The symbol is defined as external to this module. The |
| 1439 | value of the symbol must be resolved by a symbol of the |
| 1440 | same name appearing in the ESD table of another module. |
| 1441 | The ESD code which follows the type code is the code by |
| 1442 | which references to this symbol will be identified in the |
| 1443 | text. |
| 1444 | |
| 1445 | 2 The symbol is defined as an entry point in this module. |
| 1446 | It is therefore suitable for the resolution of external |
| 1447 | references in other modules. The ESD code which follows |
| 1448 | the type word identifies the program section in which |
| 1449 | this entry point appears, and the value of the symbol is |
| 1450 | relative to that section. |
| 1451 | |
| 1452 | 3 The symbol is defined as a COMMON section whose size is |
| 1453 | at least as large as specified by the value of the |
| 1454 | symbol. If several modules contain ESD entries referring |
| 1455 | to COMMON sections with the same name, a single COMMON |
| 1456 | block having the size of the largest symbol is allocated |
| 1457 | for all of them. A name consisting of blanks is treated |
| 1458 | in the same manner as any other name. |
| 1459 | |
| 1460 | 4 The symbol is defined as a section of location |
| 1461 | independent (that is, fully word-relocatable) code of a |
| 1462 | size equal to the value of the symbol. The ESD code for |
| 1463 | this section allows text from the module to be included |
| 1464 | in this section, and relocated with respect to it. |
| 1465 | |
| 1466 | 2-4 |
| 1467 | \f |
| 1468 | |
| 1469 | |
| 1470 | 5-17 Undefined |
| 1471 | |
| 1472 | The text portion of a relocatable binary file consists of the binary |
| 1473 | data to be loaded into memory, along with information directing the |
| 1474 | loader on how to modify that data to correct the addresses for program |
| 1475 | relocation. The first word of text is a control word, which is made |
| 1476 | up of a 4-bit type code and an 8-bit indicator. Following the control |
| 1477 | word, and depending on the type code, are a number of data words to be |
| 1478 | loaded as directed by the type code and the indicator. The control |
| 1479 | word type codes are: |
| 1480 | |
| 1481 | CODE FUNCTION |
| 1482 | |
| 1483 | 0 End of text, if the indicator is zero, or no operation |
| 1484 | otherwise. |
| 1485 | |
| 1486 | 1 Copy the number of words given by the indicator from text |
| 1487 | directly into memory without modification. |
| 1488 | |
| 1489 | 2 Re-origin to the section identified by the indicator, |
| 1490 | with a relative location defined by bits 9-23 of the |
| 1491 | following doubleword. Thus, the next two words define a |
| 1492 | new origin for the following text, in the program section |
| 1493 | identified by the indicator. |
| 1494 | |
| 1495 | 3 Relocate the following doubleword bits 9-23 by the value |
| 1496 | of the symbol whose ESD code is identified by the |
| 1497 | indicator. The following doubleword is usually a two- |
| 1498 | word FPP instruction, the low-order 15 bits of which are |
| 1499 | to be relocated by the value of the symbol identified by |
| 1500 | the indicator. |
| 1501 | |
| 1502 | |
| 1503 | |
| 1504 | WRITING PDP-8 CODE UNDER OS/8 FORTRAN IV |
| 1505 | |
| 1506 | |
| 1507 | RALF contains the normal set of PDP-8 instructions (TAD, DCA, CDF, |
| 1508 | KSF, etc.), however RALF does not allow literals, the PAGE pseudo-op, |
| 1509 | or the use of I to specify indirect addressing. PDP-8 code generated |
| 1510 | by RALF is not relocatable; therefore, operations such as the |
| 1511 | following are illegal: |
| 1512 | |
| 1513 | EXTERN SWAP /Illegal |
| 1514 | TAD (SWAP /Under |
| 1515 | CDF SWAP /RALF |
| 1516 | |
| 1517 | The character % appended to the end of a memory reference instruction |
| 1518 | indicates indirect addressing, and the character Z indicates a page 0 |
| 1519 | reference: |
| 1520 | |
| 1521 | |
| 1522 | |
| 1523 | |
| 1524 | |
| 1525 | 2-5 |
| 1526 | \f |
| 1527 | |
| 1528 | |
| 1529 | CURRENT PAGE PAGE ZERO |
| 1530 | DIRECT INDIRECT DIRECT INDIRECT |
| 1531 | |
| 1532 | TAD A TAD% A TADZ A TADZ% A |
| 1533 | DCA B DCA% B DCAZ B DCAZ% B |
| 1534 | |
| 1535 | Spaces are not allowed between memory reference instructions and |
| 1536 | either the Z or the % characters. The Z must precede the % when both |
| 1537 | are used. I.e., do not write "DCA%Z". |
| 1538 | |
| 1539 | Three pseudo-ops have been added to RALF: SECT8, COMMZ, and FIELD1. |
| 1540 | All three define sections of code and are handled in the same manner |
| 1541 | as SECT; however, these new sections have special meaning for the |
| 1542 | loader. The address pseudo-op (ADDR) which generates a two word re- |
| 1543 | locatable 15 bit address (i.e., JA TAG without use of JA) might prove |
| 1544 | useful in 8-mode routines. The following example demonstrates a way |
| 1545 | in which an 8-mode routine in one RALF module calls an 8-mode routine |
| 1546 | in another module: |
| 1547 | |
| 1548 | EXTERN SUB |
| 1549 | . |
| 1550 | . |
| 1551 | RIF /Set DF to current |
| 1552 | TAD ACDF /IF for return |
| 1553 | DCA .+1 |
| 1554 | 0 /CDF X |
| 1555 | TAD KSUB /Make a CIF from |
| 1556 | RTL CLL /Field bits |
| 1557 | RAL |
| 1558 | TAD ACIF |
| 1559 | DCA .+1 |
| 1560 | 0 /CIF to field |
| 1561 | /Containing SUB |
| 1562 | JMS% KSUB+1 |
| 1563 | |
| 1564 | KSUB, ADDR SUB /Psuedo-op to |
| 1565 | /Generate 15 bit |
| 1566 | /ADDR of subroutine |
| 1567 | /SUB |
| 1568 | ACDF, CDF |
| 1569 | ACIF, CIF |
| 1570 | |
| 1571 | In general the address pseudo-op can be used to supply an 8-mode |
| 1572 | section with an argument or pointer external to the section. |
| 1573 | |
| 1574 | FPP and 8-mode code may be intermixed in any RALF section. PDP-8 mode |
| 1575 | routines must be called in FPP mode by either: |
| 1576 | |
| 1577 | TRAP3 SUB |
| 1578 | |
| 1579 | or TRAP4 SUB |
| 1580 | |
| 1581 | A TRAP3 SUB causes FRTS to generate a JMP SUB with interrupts on and |
| 1582 | the FPP hardware (if any) halted. TRAP4 generates a JMS SUB under the |
| 1583 | |
| 1584 | 2-6 |
| 1585 | \f |
| 1586 | |
| 1587 | |
| 1588 | same conditions. The return from TRAP4 is: |
| 1589 | |
| 1590 | CDF CIF 0 |
| 1591 | JMP% SUB |
| 1592 | |
| 1593 | The return from TRAP3 is: |
| 1594 | |
| 1595 | CDF CIF 0 |
| 1596 | JMP% RETURN+1 |
| 1597 | EXTERN #RETRN |
| 1598 | RETURN, ADDR #RETRN |
| 1599 | |
| 1600 | |
| 1601 | Communication between FPP and 8-mode routines is best done at the FPP |
| 1602 | level because of greater flexibility in both addressing and relocation |
| 1603 | in FPP mode. The following routine demonstrates how to pass an argu- |
| 1604 | ment to, and retrieve an argument from, an 8-mode routine: |
| 1605 | |
| 1606 | EXTERN SUB |
| 1607 | EXTERN SUBIN |
| 1608 | EXTERN SUBOUT |
| 1609 | . |
| 1610 | . |
| 1611 | . |
| 1612 | FLDA X /Arg for SUB |
| 1613 | FSTA SUBIN |
| 1614 | TRAP4 SUB /Call SUB |
| 1615 | FLDA SUBOUT /Get result |
| 1616 | FSTA Y |
| 1617 | |
| 1618 | If the 8-mode routine SUB were in the same module as the FPP routine, |
| 1619 | the externs would not be necessary. In practice it is common for FPP |
| 1620 | and 8-mode routines that communicate with one another to be in the |
| 1621 | same section. A number of techniques can be used to pass arguments. |
| 1622 | For example, an FPP routine could move the index registers to an |
| 1623 | 8-mode section and pass single precision arguments via ATX. |
| 1624 | |
| 1625 | Because 8-mode routines are commonly used in conjunction with FPP code |
| 1626 | (generated by the compiler), the 8-mode programmer should be familiar |
| 1627 | with OS/8 FORTRAN IV subroutine calling conventions. The general code |
| 1628 | for a subroutine call is a JSR, followed by a JA around a list of |
| 1629 | arguments, followed by a list of pointers to the arguments. The FPP |
| 1630 | code for the statement: |
| 1631 | |
| 1632 | CALL SUB (X,Y,Z) |
| 1633 | |
| 1634 | would be |
| 1635 | |
| 1636 | EXTERN SUB |
| 1637 | JSR SUB |
| 1638 | JA BYARG |
| 1639 | JA X |
| 1640 | JA Y |
| 1641 | JA Z |
| 1642 | |
| 1643 | 2-7 |
| 1644 | \f |
| 1645 | |
| 1646 | |
| 1647 | BYARG, . |
| 1648 | . |
| 1649 | . |
| 1650 | . |
| 1651 | |
| 1652 | The general format of every subroutine obeys the following scheme: |
| 1653 | |
| 1654 | SECT SUB |
| 1655 | JA #ST /Jump to start of |
| 1656 | /Routine |
| 1657 | TEXT +SUB+ /Needed for |
| 1658 | /Trace back |
| 1659 | RTN, SETX XSUB /Reset SUB's index |
| 1660 | SETB BSUB /And base page |
| 1661 | BSUB, FNOP /Start of base page |
| 1662 | JA . |
| 1663 | . |
| 1664 | . |
| 1665 | ORG BSUB+30 /Restart for SUB |
| 1666 | FNOP:JA RTN |
| 1667 | GOBAK, FNOP:JA . /Return to |
| 1668 | /Calling program |
| 1669 | |
| 1670 | Location 00000 of the calling routine's base page points to the list |
| 1671 | of arguments, if any, and may be used by the called subroutine |
| 1672 | provided that it is not modified. Location 0003 of the calling |
| 1673 | routine's base page is free for use by the called subroutine. |
| 1674 | |
| 1675 | Location 0030 of the calling routine's base page contains the address |
| 1676 | where execution is to continue upon exit from the subroutine, so that |
| 1677 | a subroutine should not return from a JSR call via location 0 of the |
| 1678 | calling routine: |
| 1679 | |
| 1680 | CORRECT INCORRECT |
| 1681 | |
| 1682 | FLDA 30 FLDA 0 |
| 1683 | JAC JAC |
| 1684 | |
| 1685 | The "non-standard" return allows the calling routine to reset its own |
| 1686 | index registers and base page before continuing in-line execution. |
| 1687 | General initialization code for a subroutine would be: |
| 1688 | |
| 1689 | SECT SUB |
| 1690 | JA #ST |
| 1691 | . |
| 1692 | . |
| 1693 | . |
| 1694 | BASE 0 |
| 1695 | |
| 1696 | #ST, STARTD /So only 2 words |
| 1697 | /Will be picked up |
| 1698 | FLDA 30 /Get return JA |
| 1699 | FSTA GOBAK /Save it |
| 1700 | FLDA 0 /Get pointer to list |
| 1701 | |
| 1702 | 2-8 |
| 1703 | \f |
| 1704 | |
| 1705 | |
| 1706 | SETX XSUB /Set SUB's XR |
| 1707 | SETB BSUB /Set SUB's Base |
| 1708 | BASE BSUB |
| 1709 | INDEX XSUB |
| 1710 | FSTA BSUBX /Store pointer |
| 1711 | /Somewhere on Base |
| 1712 | . |
| 1713 | . |
| 1714 | . |
| 1715 | STARTF /Set F mode before |
| 1716 | JA GOBAK /Return |
| 1717 | |
| 1718 | The above code can be optimized for routines that do not require full |
| 1719 | generality. The JA #ST around the base page code is a convenience |
| 1720 | which may be omitted. The three words of text are necessary only for |
| 1721 | error traceback and may also be omitted. If the subroutine is not |
| 1722 | going to call any general subroutines, the SETX and SETB instructions |
| 1723 | at location RTN and the JA RTN at location 0030 are not necessary. If |
| 1724 | the subroutine does not require a base page, the SETB instruction is |
| 1725 | not necessary in subroutine initialization; similar remarks apply to |
| 1726 | index registers. If neither base page nor index registers are |
| 1727 | modified by the subroutine, the return sequence: |
| 1728 | |
| 1729 | FLDA 0 |
| 1730 | JAC |
| 1731 | |
| 1732 | is also legal. In a subroutine call, the JA around the list of argu- |
| 1733 | ments is unnecessary when there are no arguments. A RALF listing of |
| 1734 | a FORTRAN source will provide a good reference of general FPP coding |
| 1735 | conventions. |
| 1736 | |
| 1737 | In order to generate good 8-mode code, one must be aware of the manner |
| 1738 | in which the loader links and relocates RALF code. The loader handles |
| 1739 | three 8-mode section types: COMMZ, FIELD1, and SECT8. All three |
| 1740 | types of section are forced to begin and end on page boundaries and to |
| 1741 | be a part of level MAIN; 8-mode sections never reside in overlays. |
| 1742 | COMMZ and FIELD1 sections are forced to reside in field 1; SECT |
| 1743 | sections may be in any field. The first COMMZ section encountered is |
| 1744 | forced to begin at location 10000, thus enabling a page 0 in field 1. |
| 1745 | COMMZ sections of the same name are handled like COMMON sections of |
| 1746 | the same name (i.e., they are combined into one common section). This |
| 1747 | feature allows 8-mode code in different modules to share page 0, pro- |
| 1748 | vided that the modules do not destroy each other's page 0 allocations. |
| 1749 | Suppose two modules were to share page 0, with the first using |
| 1750 | location 0-17 and the second using locations 20-37: |
| 1751 | |
| 1752 | /Module A |
| 1753 | COMMZ SHARE |
| 1754 | P1, 1 |
| 1755 | P2, 2 |
| 1756 | KSUBA1, SUBA1 |
| 1757 | KSUBA2, SUBA2 |
| 1758 | . |
| 1759 | . |
| 1760 | |
| 1761 | 2-9 |
| 1762 | \f |
| 1763 | |
| 1764 | |
| 1765 | . /Should not go over |
| 1766 | LASTA, -1 /20 locations |
| 1767 | |
| 1768 | FIELD1 A |
| 1769 | |
| 1770 | TADZ P1 |
| 1771 | JMSZ% KSUBA1 |
| 1772 | . |
| 1773 | . |
| 1774 | . /Module B |
| 1775 | COMMZ SHARE |
| 1776 | ORG .+20 /ORG past module A's |
| 1777 | /Page 0 |
| 1778 | P3, 3 |
| 1779 | P4, 4 |
| 1780 | KSUBB, SUBB |
| 1781 | . |
| 1782 | . |
| 1783 | . |
| 1784 | LASTB -2 |
| 1785 | FIELD1 B |
| 1786 | TADZ P3 |
| 1787 | . |
| 1788 | . |
| 1789 | . |
| 1790 | |
| 1791 | The two COMMZ sections will be put on top of one another, however, |
| 1792 | because of the ORG .+20 in module B, they will effectively reside back |
| 1793 | to back. When the image is loaded, the COMMZ sections will look as |
| 1794 | follows: |
| 1795 | |
| 1796 | LOC CONTENTS |
| 1797 | |
| 1798 | 1 0000 1 |
| 1799 | 0001 2 |
| 1800 | 2 SUBA1 |
| 1801 | 3 SUBA2 |
| 1802 | . |
| 1803 | . |
| 1804 | . |
| 1805 | 1 0017 -1 /LASTA |
| 1806 | 1 0020 3 |
| 1807 | 21 4 |
| 1808 | 22 SUBB |
| 1809 | . |
| 1810 | . |
| 1811 | . |
| 1812 | 37 -2 /LASTB |
| 1813 | |
| 1814 | If module A is to reference module B's page 0, the procedure is: |
| 1815 | |
| 1816 | P3=20 |
| 1817 | TADZ P3 |
| 1818 | |
| 1819 | |
| 1820 | 2-10 |
| 1821 | \f |
| 1822 | |
| 1823 | |
| 1824 | Alternately, a duplicate of the source code for COMMZ SHARE may be |
| 1825 | included in module B. Modules that are using the same COMMZ section |
| 1826 | must be aware of how it is divided up. Although COMMZ SHARE takes only |
| 1827 | 40 locations, the loader allocates a full 200 locations to it. All |
| 1828 | 8-mode section core allocations are always rounded up so that they |
| 1829 | terminate on a page boundary. If COMMZ sections of different names |
| 1830 | exist, they are accepted by the loader and inserted into field 1, but |
| 1831 | only one COMMZ is the real page 0. In general, it is unwise to have |
| 1832 | more than 1 COMMZ section name. |
| 1833 | |
| 1834 | FIELD1 sections are identical to COMMZ sections in most respects. |
| 1835 | Memory allocation for FIELD1 sections is assigned after COMMZ sections, |
| 1836 | however, and FIELD1 sections are combined with FORTRAN COMMON sections |
| 1837 | of the same name as well as other FIELD1 sections of the same name. |
| 1838 | The first difference ensures that COMMZ will be allocated page 0 |
| 1839 | storage even in the presence of FIELD1 sections. The second allows |
| 1840 | PDP-8 code to be loaded into COMMON, making it possible to load |
| 1841 | initialization code into data buffers. Two FIELD1 sections with the |
| 1842 | same name may be combined in the same manner as two COMMZ, sections. |
| 1843 | |
| 1844 | The primary purpose of COMMZ is to provide a PDP-8 page 0; the primary |
| 1845 | purpose of FIELD1 is to ensure that 8-mode code will be loaded into |
| 1846 | field 1 and that generating CIF CDF instructions in-line is not neces- |
| 1847 | sary. SECT8 sections may not be combined in the manner of a COMMON |
| 1848 | and are not ensured of being placed into field 1. |
| 1849 | |
| 1850 | An 8-mode section does not have to be less than a page in length; |
| 1851 | however, the programmer should be aware that a SECT8 section which |
| 1852 | exceeds one page may be loaded across a field boundary and could |
| 1853 | thereby produce disastrous results at execution time. For this |
| 1854 | reason, it is generally unwise to cross pages in SECT8 code. This |
| 1855 | situation will never occur on an 8K configuration. If the total |
| 1856 | amount of COMMZ and FIELD1 code exceeds 4K, the loader generates an |
| 1857 | OVER CORE message. The loader generates an MS error for any of the |
| 1858 | following: |
| 1859 | |
| 1860 | 1. A COMMZ section name is identical to some entry point or some |
| 1861 | non-COMMZ section name. |
| 1862 | |
| 1863 | 2. A FIELD1 section name is identical to some entry point or a |
| 1864 | SECT, SECT8 or COMMZ section name. |
| 1865 | |
| 1866 | 3. A SECT8 section name is identical to an entry point or some |
| 1867 | other section name. |
| 1868 | |
| 1869 | COMMZ sections, like FORTRAN COMMONS, are never entered in the library |
| 1870 | catalog. |
| 1871 | |
| 1872 | For users who intend to write 8-mode code that will execute in |
| 1873 | conjunction with certain 8-mode library routines, the layout of PDP-8 |
| 1874 | FIELD1 #PAGE 0 is: |
| 1875 | |
| 1876 | |
| 1877 | |
| 1878 | |
| 1879 | 2-11 |
| 1880 | \f |
| 1881 | |
| 1882 | |
| 1883 | LOCATION USE |
| 1884 | |
| 1885 | 0-1 Temps for any non-interrupt time routine. |
| 1886 | 2-13 User locations. |
| 1887 | 14-157 System locations. |
| 1888 | 160-177 User locations. |
| 1889 | |
| 1890 | 1. Do not define any COMMZ sections other than the system COMMZ |
| 1891 | which is #PAGE0. |
| 1892 | |
| 1893 | 2. If the system page 0 is desired, it will be pulled in from |
| 1894 | the library if EXTERN #DISP appears in the code. |
| 1895 | |
| 1896 | 3. Do not use any part of page 0 reserved for the system. |
| 1897 | |
| 1898 | Special purpose PDP-8 mode subroutines may be written to perform idle |
| 1899 | jobs (refreshing a scope, checking sense lines) or to handle specific |
| 1900 | interrupts not serviced by FRTS. |
| 1901 | |
| 1902 | The run-time system enters idle loops while waiting for the FPP to |
| 1903 | complete a task or for an I/O job to complete. It is possible to |
| 1904 | effect a JMS to a user routine during the idle loop. |
| 1905 | |
| 1906 | RTS contains a set of instructions such as: |
| 1907 | |
| 1908 | #IDLE, JMP .+4 |
| 1909 | 0 |
| 1910 | CDF CIF |
| 1911 | JMS I .-2 |
| 1912 | |
| 1913 | This sequence of instructions must be revised if an IDLE routine is to |
| 1914 | be called. |
| 1915 | |
| 1916 | The location #IDLE must be changed to a SKP (7410). #IDLE+1 must be |
| 1917 | set to the address of the routine to be called. #IDLE+2 must be set |
| 1918 | to a CDF CIF to the field of the routine. This setup can be done in a |
| 1919 | routine that is called at the beginning of MAIN. For example: |
| 1920 | |
| 1921 | CALL SETIDL |
| 1922 | |
| 1923 | where SETIDL is a routine such as: |
| 1924 | |
| 1925 | SECT8 SETIDL /Must be an 8-mode section |
| 1926 | JA #RET |
| 1927 | TEXT +SETIDL+ /Traceback information |
| 1928 | SXR, SETX XR |
| 1929 | SETB BP |
| 1930 | BP, 0.0 |
| 1931 | XR, 0.0 |
| 1932 | . |
| 1933 | . |
| 1934 | . |
| 1935 | |
| 1936 | |
| 1937 | |
| 1938 | 2-12 |
| 1939 | \f |
| 1940 | |
| 1941 | |
| 1942 | ORG 10*3+BP |
| 1943 | FNOP /For trace back |
| 1944 | JA SXR |
| 1945 | . |
| 1946 | 0 |
| 1947 | RET, JA . /Return address |
| 1948 | . |
| 1949 | . |
| 1950 | . |
| 1951 | #RET, STARTD /Set up |
| 1952 | FLDA 10*3 /Return address |
| 1953 | FSTA RET |
| 1954 | SETB BP /Just for traceback |
| 1955 | TRAP4 SET8 /Go to the 8 mode |
| 1956 | /Routine set 8 |
| 1957 | STARTF |
| 1958 | JA RET /Return to main |
| 1959 | SET8, 0 |
| 1960 | TAD IDLAD /Field of idle |
| 1961 | CLL RTL |
| 1962 | RAL /Move to |
| 1963 | /Bits 6-8 |
| 1964 | TAD SCDF /CDF to #IDLE |
| 1965 | DCA .+3 |
| 1966 | TAD IDLAD+1 /Address of #IDLE |
| 1967 | DCA IDPTR |
| 1968 | 0 /CDF goes here |
| 1969 | TAD S7410 /SKP |
| 1970 | DCA% IDPTR /Store at #IDLE |
| 1971 | TAD JOB+1 /Address of IDLE top routine |
| 1972 | ISZ IDPTR |
| 1973 | DCA IDPTR /Store a #IDLE+1 |
| 1974 | TAD JOB /Field of routine |
| 1975 | CLL RTL |
| 1976 | RAL /Position |
| 1977 | TAD SFIELD |
| 1978 | ISZ IDPTR |
| 1979 | DCA% IDPTR /Store at #IDLE+2 |
| 1980 | CDF CIF /Set to field 0 |
| 1981 | JMP% SET8 /Return to instruction |
| 1982 | /Following "TRAP4 SET8" |
| 1983 | EXTERN #IDLE |
| 1984 | IDLAD, ADDR #IDLE /15 bit address of IDLE |
| 1985 | JOB, ADDR DOIT /15 bit address of IDLE |
| 1986 | /Routine "DOIT" |
| 1987 | SCDF, 6201 /CDF |
| 1988 | SFIEL, 6203 /CDF CIF |
| 1989 | IDPTR, 0 |
| 1990 | S7410, 7410 /Skip |
| 1991 | |
| 1992 | /The following routine performs the |
| 1993 | /IDLE task |
| 1994 | /Executed during IDLE loops |
| 1995 | |
| 1996 | |
| 1997 | 2-13 |
| 1998 | \f |
| 1999 | |
| 2000 | |
| 2001 | DOIT, 0 |
| 2002 | . |
| 2003 | . |
| 2004 | . /Perform task |
| 2005 | . |
| 2006 | CDF CIF 0 /Back to field 0 |
| 2007 | JMP% DOIT /And back |
| 2008 | |
| 2009 | If the subroutine is checking for an illegal argument, an argument |
| 2010 | error message with traceback can be included in the subroutine by |
| 2011 | adding two lines somewhere on the base pages |
| 2012 | |
| 2013 | EXTERN #ARGER |
| 2014 | EXAMER, TRAP4 #ARGER |
| 2015 | |
| 2016 | When the error is detected in the program, effect a jump to the TRAP4 |
| 2017 | instruction. For example, |
| 2018 | |
| 2019 | FLDA% EXTMP1 |
| 2020 | JEQ EXAMER /A value of 0 is illegal |
| 2021 | or |
| 2022 | |
| 2023 | FLDA EXTMP1 |
| 2024 | FNEG |
| 2025 | FADD EXTMP2 |
| 2026 | JLT EXAMER /The value in EXTMP1 must be |
| 2027 | /greater than that in EXTMP2 |
| 2028 | |
| 2029 | Some points to note in the above example |
| 2030 | |
| 2031 | 1. Using a # as the first character in the name of the start of the |
| 2032 | program assumes that the name is not called from the FORTRAN level. |
| 2033 | This is because # is an illegal FORTRAN keyboard character. |
| 2034 | |
| 2035 | 2. If index registers 3-5 are not used by the subroutine, the space |
| 2036 | from XR3 to the ORG statement can be used for temporary storage, |
| 2037 | if needed. |
| 2038 | |
| 2039 | 3. The arguments passed from the FORTRAN level do not have to be |
| 2040 | picked up all at once at the start of the calculation (3-word) |
| 2041 | portion of the program. They can be picked up as required during |
| 2042 | the program, can be saved in temporary space, or accessed |
| 2043 | indirectly each time required, as best suits the subroutine. |
| 2044 | |
| 2045 | If a call to this routine such as Z=EXAMPL(A,B,C,D) were encountered |
| 2046 | by the compiler, it would generate the following call to the routine: |
| 2047 | |
| 2048 | JSR EXAMPL /go to the routine |
| 2049 | JA .+10 /jump around arguments |
| 2050 | JA A /pointer to lst argument |
| 2051 | JA B /pointer to 2nd argument |
| 2052 | JA C /pointer to 3rd argument |
| 2053 | JA D /pointer to 4th argument |
| 2054 | |
| 2055 | |
| 2056 | 2-14 |
| 2057 | \f |
| 2058 | |
| 2059 | |
| 2060 | The AMOD routine is listed below to illustrate an application of the |
| 2061 | formal calling sequence. It also includes an error condition check |
| 2062 | and picks up two arguments. When called from FORTRAN, the code is |
| 2063 | AMOD(X,Y). |
| 2064 | |
| 2065 | / |
| 2066 | / |
| 2067 | / |
| 2068 | / A M O D |
| 2069 | / - - - - |
| 2070 | / |
| 2071 | /SUBROUTINE AMOD(X,Y) |
| 2072 | SECT AMOD /SECTION NAME(REAL NUMBERS) |
| 2073 | ENTRY MOD /ENTRY POINT NAME(INTEGERS) |
| 2074 | JA #AMOD /JUMP TO START OF ROUTINE |
| 2075 | TEXT +AMOD + /FOR ERROR TRACE BACK |
| 2076 | AMODXR, SETX XRAMOD /SET INDEX REGISTERS |
| 2077 | SETB BPAMOD /ASSIGN BASE PAGE |
| 2078 | BPAMOD, F 0.0 /BASE PAGE |
| 2079 | XRAMOD, F 0.0 /INDEX REGS. |
| 2080 | AMODX, F 0.0 /TEMP STORAGE |
| 2081 | ORG 10*3+BPAMOD /RETURN SEQUENCE |
| 2082 | FNOP |
| 2083 | JA AMODXR |
| 2084 | 0 |
| 2085 | AMDRTN, JA . /EXIT |
| 2086 | EXTERN #ARGER |
| 2087 | AMODER, TRAP4 #ARGER /PRINT AN ERROR MESSAGE |
| 2088 | FCLA /EXIT WITH FAC=0 |
| 2089 | JA AMDRTN |
| 2090 | BASE 0 /STAY ON CALLER'S BASE PG |
| 2091 | /LONG ENOUGH TO GET RETURN ADDRESS |
| 2092 | MOD, /START OF INTEGER ROUTINE SAME AS |
| 2093 | #AMOD, STARTD /START OF REAL NUM. ROUTINE |
| 2094 | FLDA 10*3 /GET RETURN JUMP |
| 2095 | FSTA AMDRTN /SAVE IN THIS PROGRAM |
| 2096 | FLDA 0 /GET POINTER TO PASSED ARG |
| 2097 | SETX XRAMOD /ASSIGN MOD'S INDEX REGS |
| 2098 | SETB BPAMOD /AND ITS BASE PAGE |
| 2099 | BASE BPAMOD |
| 2100 | LDX 1,1 |
| 2101 | FSTA BPAMOD |
| 2102 | FLDA% BPAMOD,1 /ADDR OF X |
| 2103 | FSTA AMODX |
| 2104 | FLDA% BPAMOD,1+ /ADDR OF Y |
| 2105 | FSTA BPAMOD |
| 2106 | STARTF |
| 2107 | FLDA% BPAMOD /GET Y |
| 2108 | JEQ AMODER /Y=0 IS ERROR |
| 2109 | JGT .+3 |
| 2110 | FNEG /ABS VALUE |
| 2111 | FSTA BPAMOD |
| 2112 | FLDA% AMODX /GET X |
| 2113 | JGT .+5 |
| 2114 | |
| 2115 | 2-15 |
| 2116 | \f |
| 2117 | |
| 2118 | |
| 2119 | FNEG /ABS VALUE |
| 2120 | LDX 0,1 /NOTE SIGN |
| 2121 | FSTA AMODX /SAVE IN A TEMPORARY |
| 2122 | FDIV BPAMOD /DIVIDE BY Y |
| 2123 | JAL AMODER /TOO BIG. |
| 2124 | ALN 0 /FIX IT UP NOW. |
| 2125 | FNORM |
| 2126 | FMUL BPAMOD /MULTIPLY IT. |
| 2127 | FNEG /NEGATE IT. |
| 2128 | FADD AMODX /AND ADD IN X. |
| 2129 | JXN AM,1 /CHECK SIGN |
| 2130 | FNEG |
| 2131 | AM, JA AMDRTN /DONE |
| 2132 | |
| 2133 | RTS has its own interrupt skip chain in which all on-line device flags |
| 2134 | are checked and serviced. This chain may be extended to handle |
| 2135 | special interrupts. The external tag #INT marks the first of three |
| 2136 | locations on RTS which have to be modified to effect a JMS to the |
| 2137 | user's special interrupt handler. The three locations must be set up |
| 2138 | in exactly the same manner as that used to set up #IDLE, #IDLE1, |
| 2139 | #IDLE2 as described above. All the same conventions hold. Refer also |
| 2140 | to the library subroutines ONQI and ONQB. |
| 2141 | |
| 2142 | Three pseudo-ops have been added to RALF to help the loader determine |
| 2143 | core allocation. Each is a more definitive case of the SECT pseudo-op |
| 2144 | and defines a chunk of code, thereby providing more control for the |
| 2145 | user. They are: |
| 2146 | |
| 2147 | SECT8 - section starts at a page boundary |
| 2148 | FIELD1 - section starts at a page boundary and is in field 1 |
| 2149 | COMMZ - section starts at page 0 of field 1 |
| 2150 | |
| 2151 | If there is more than one SECT8 section in a module, those sections |
| 2152 | are not necessarily loaded in contiguous core. The loader considers |
| 2153 | core to be in two chunks - one block in field 0, and all of field 1 |
| 2154 | and above. |
| 2155 | |
| 2156 | If there is more than one COMMZ pseudo-op in a module, they are |
| 2157 | stacked one behind the other, but there is no way of specifying which |
| 2158 | one starts at absolute location 0 of field 1. COMMZ sections are |
| 2159 | allocated by the loader before FIELD1 sections. |
| 2160 | |
| 2161 | Modules can share a COMMZ section in the same way that FORTRAN COMMON |
| 2162 | sections can be shared. FIELD1 sections can also be shared by using |
| 2163 | the same FIELD1 section name in each module. |
| 2164 | |
| 2165 | The first occurrence of a section name defines that section. For |
| 2166 | example, |
| 2167 | |
| 2168 | SECT8 PARTA |
| 2169 | . |
| 2170 | . |
| 2171 | . |
| 2172 | SECT8 PARTB |
| 2173 | |
| 2174 | 2-16 |
| 2175 | \f |
| 2176 | |
| 2177 | |
| 2178 | . |
| 2179 | . |
| 2180 | . |
| 2181 | SECT8 PARTA |
| 2182 | |
| 2183 | The second mention of PARTA in the same module continues the source |
| 2184 | where the first mention of PARTA ended at execution time. (There is |
| 2185 | a location counter for each section.) |
| 2186 | |
| 2187 | To save core, a RALF FIELD1 section and FORTRAN COMMON section of the |
| 2188 | same name are mapped on top of each other, being allocated the length |
| 2189 | of the longer and the same absolute address by the loader. This |
| 2190 | feature is useful for initialization (once-only) code, which can |
| 2191 | later be overlayed by a data area. Thus, the occurrence of FIELD1 |
| 2192 | AREA1 in the RALF module and COMMON AREA1 in the FORTRAN program |
| 2193 | causes AREA1 to start the same location (in field 1) and have a length |
| 2194 | of at least 200 locations (depending on the length of the RALF FIELD1 |
| 2195 | section or of the COMMON section in the FORTRAN). |
| 2196 | |
| 2197 | If the subroutine is longer than one page and values are to be passed |
| 2198 | across page boundaries, the address pseudo-op, ADDR, is required. |
| 2199 | The format is: |
| 2200 | |
| 2201 | AVAR1, ADDR VAR1 |
| 2202 | |
| 2203 | This generates a two-word reference to the proper location on another |
| 2204 | page, here VAR1. For example, to pass a value to VAR1, possible code |
| 2205 | is: |
| 2206 | |
| 2207 | 00124 1244 TAD VAR2 /Value on this page |
| 2208 | 00125 3757 DCA% AVAR1+1 /Pass through 12-bit |
| 2209 | . /location |
| 2210 | 00156 0000 AVAR1,ADDR VAR1 /Field and |
| 2211 | 00157 0322 /location of VAR1 |
| 2212 | |
| 2213 | Any reference to an absolute address can be effected by the ADDR |
| 2214 | pseudo-op. |
| 2215 | |
| 2216 | If it is doubtful that the effective address is in the current data |
| 2217 | field, it is necessary to create a CDF instruction to the proper field. |
| 2218 | In the above example, suitable code to add to specify the data field |
| 2219 | is: |
| 2220 | |
| 2221 | TAD AVAR1 /Get field bits |
| 2222 | RTL /Rotate to bits 6-8 |
| 2223 | RAL |
| 2224 | TAD (6201 /Add a CDF |
| 2225 | DCA .+1 /Deposit in line |
| 2226 | 0 /Execute CDFn |
| 2227 | |
| 2228 | If the subroutine includes an off-page reference to another RALF |
| 2229 | module (e.g., in FORLIB), it can be addressed by using an EXTERN |
| 2230 | with an ADDR pseudo-op. For example, in the display program, a ref- |
| 2231 | erence to the non-interrupt task subroutine ONQB is coded as |
| 2232 | |
| 2233 | 2-17 |
| 2234 | \f |
| 2235 | |
| 2236 | |
| 2237 | EXTERN ONQB |
| 2238 | ONQBX, ADDR ONQB |
| 2239 | |
| 2240 | and is called by |
| 2241 | |
| 2242 | JMS% ONQBX+1 |
| 2243 | |
| 2244 | The next instruction in the program is ADDR DISPLY so that DISPLY will |
| 2245 | be added to the background list. Execution from ONQB returns after |
| 2246 | the ADDR pseudo-op. |
| 2247 | |
| 2248 | It may be desirable to salvage the first (field) word allocated by |
| 2249 | ADDR pseudo-ops. If the address requires only twelve bite for proper |
| 2250 | execution, code such as |
| 2251 | |
| 2252 | TMP, TMP,ADDR X |
| 2253 | ARG,ADDR X or ARG= .-1 |
| 2254 | |
| 2255 | permits TMP to be used for temporary storage because ARG+1 in the left |
| 2256 | hand example or just ARG in the right hand example defines the 12-bit |
| 2257 | address. |
| 2258 | |
| 2259 | RALF does not recognize LINC instruction or PDP-8 laboratory device |
| 2260 | instructions. Such instructions can be included in the subroutine by |
| 2261 | defining them by equate statements in the program. |
| 2262 | |
| 2263 | For example, adding the statements: |
| 2264 | |
| 2265 | PDP = 2 |
| 2266 | LINC = 6141 |
| 2267 | DIS = 140 |
| 2268 | |
| 2269 | takes care of all instructions for coding the PDP-12 display |
| 2270 | subroutine. |
| 2271 | |
| 2272 | When writing a routine that is going to be longer than a page, it can |
| 2273 | be useful to have a non-fixed origin in order not to waste core and to |
| 2274 | facilitate modification of the code. A statement such as |
| 2275 | |
| 2276 | IFPOS .-SECNAM&177-K<ORG .-SECNAM&7600+200+SECNAM> |
| 2277 | |
| 2278 | will start a new page only if the value [current location less section |
| 2279 | name] is greater than some K (start of section has a relative value of |
| 2280 | 0) where K<=177 and is the relative location on the current page |
| 2281 | before which a new page should be started. The ORG statement includes |
| 2282 | an AND mask of 7600 to preserve the current page. When added to 200 |
| 2283 | for the next page and the section name, the new origin is set. |
| 2284 | |
| 2285 | When calculating directly in a module, the following rules apply to |
| 2286 | relative and absolute values. |
| 2287 | |
| 2288 | |
| 2289 | |
| 2290 | |
| 2291 | |
| 2292 | 2-18 |
| 2293 | \f |
| 2294 | |
| 2295 | |
| 2296 | relative - relative = absolute |
| 2297 | absolute + relative = relative |
| 2298 | OR (!), AND (&) and ADD (+) of relative symbols |
| 2299 | generate the RALF error message RE. |
| 2300 | |
| 2301 | When passing arguments (single precision) from FPP code to PDP code, |
| 2302 | using the index registers is very efficient. For example, |
| 2303 | |
| 2304 | . |
| 2305 | . |
| 2306 | . |
| 2307 | FLDA% ARG1 /Get argument in FPP mode |
| 2308 | SETX MODE8 /Change index registers so XR0 is |
| 2309 | /At MODE8 |
| 2310 | ATX MODE8 /Save argument |
| 2311 | . |
| 2312 | . |
| 2313 | . |
| 2314 | TRAP4 SUB8 /Go to PDP-8 routine |
| 2315 | . |
| 2316 | . |
| 2317 | . |
| 2318 | SUB8, 0 /PDP-8 routine |
| 2319 | . |
| 2320 | . |
| 2321 | . |
| 2322 | TAD MODE8 /Get argument |
| 2323 | . |
| 2324 | . |
| 2325 | . |
| 2326 | MODE8, 0 /Index registers set here |
| 2327 | . |
| 2328 | . |
| 2329 | . |
| 2330 | |
| 2331 | |
| 2332 | |
| 2333 | |
| 2334 | |
| 2335 | |
| 2336 | |
| 2337 | |
| 2338 | |
| 2339 | |
| 2340 | |
| 2341 | |
| 2342 | |
| 2343 | |
| 2344 | |
| 2345 | |
| 2346 | |
| 2347 | |
| 2348 | |
| 2349 | |
| 2350 | |
| 2351 | 2-19 |
| 2352 | \f |
| 2353 | |
| 2354 | |
| 2355 | CHAPTER 3 |
| 2356 | |
| 2357 | THE FORTRAN IV LOADER |
| 2358 | |
| 2359 | |
| 2360 | The FORTRAN IV loader accepts a set of (up to 128) RALF modules as |
| 2361 | input, and links the modules, along with any necessary library |
| 2362 | components, to form a loader image file that may be read into memory |
| 2363 | and executed by the run-time system. The main task accomplished by the |
| 2364 | loader is program relocation, achieved by replacing the relative |
| 2365 | starting address of every section with an absolute core address. |
| 2366 | Absolute addresses are also assigned to all entry points, all |
| 2367 | relocatable binary text, and the externs. |
| 2368 | |
| 2369 | The loader executes in three passes. Pass 0 begins by determining how |
| 2370 | much memory is available on the running hardware configuration, and |
| 2371 | then constructs tables from the OS/8 command decoder input for use by |
| 2372 | pass 1 and pass 2. |
| 2373 | |
| 2374 | Pass 1 reads the relocatable binary input and creates the loader |
| 2375 | symbol table. The length of each input module is computed and stored, |
| 2376 | along with the relative values of entry points defined within the |
| 2377 | input modules. When an undefined symbol is encountered, pass 1 |
| 2378 | searches the catalog of the FORTRAN IV library specified to pass 0, |
| 2379 | or FORLIB.RL if no other library was explicitly specified, and loads |
| 2380 | the library routine corresponding to the undefined symbol. |
| 2381 | |
| 2382 | Pass 1 also allocates absolute core addresses to all modules and, |
| 2383 | through them, to all symbols. Pass 1 execution concludes by computing |
| 2384 | the lengths of all overlay levels defined for the current FORTRAN IV |
| 2385 | job. Trap vectors are also set up at this time, and the tables |
| 2386 | required for pass 2 loading are initialized. |
| 2387 | |
| 2388 | Pass 2 concludes loader execution by creating a loader image file from |
| 2389 | the relocated binary input and symbol values processed by pass 1. |
| 2390 | Pass 2 also produces the loader symbol map, if requested, and chains |
| 2391 | to the run-time system if /G was specified. |
| 2392 | |
| 2393 | Pass 0 contains very few subroutines. The routine CORDSW checks for |
| 2394 | the presence of /U, /C or /O option specifications, as supplied to the |
| 2395 | command decoder, and processes these options if necessary. A routine |
| 2396 | called UPDMOD is called when input to each overlay has been concluded, |
| 2397 | to update the module counts in the module count table. |
| 2398 | |
| 2399 | CORMOV is a general core-moving subroutine, called by the instruction |
| 2400 | sequence: |
| 2401 | |
| 2402 | JMS CORMOV |
| 2403 | CDF FROMFIELD |
| 2404 | FROMADDR - 1 |
| 2405 | CDF TOFIELD |
| 2406 | TOADDR - 1 |
| 2407 | - COUNT |
| 2408 | |
| 2409 | |
| 2410 | 3-1 |
| 2411 | \f |
| 2412 | |
| 2413 | |
| 2414 | LOADER PASS 0 (FILE COLLECTION) |
| 2415 | ------------------------------ |
| 2416 | 00000 | OS/8 Command Decoder | FIELD 0 |
| 2417 | | | |
| 2418 | | | |
| 2419 | |----------------------------| |
| 2420 | 02000 | Loader Pass 1 and | |
| 2421 | | Pass 2 | |
| 2422 | | | |
| 2423 | |----------------------------| |
| 2424 | 04600 | Core measuring routine | |
| 2425 | | and scratch area to | |
| 2426 | | save 00000-02000 | |
| 2427 | | during CD calls | |
| 2428 | |----------------------------| |
| 2429 | 06600 | | |
| 2430 | | Unused | |
| 2431 | | | |
| 2432 | |----------------------------| |
| 2433 | 07600 | OS/8 Field 0 resident | |
| 2434 | |----------------------------| |
| 2435 | 10000 | OS/8 User Service Routine | FIELD 1 |
| 2436 | | | |
| 2437 | | | |
| 2438 | |----------------------------| |
| 2439 | 12000 | Symbol table, loader map | |
| 2440 | | titles | |
| 2441 | 12400 | | |
| 2442 | |----------------------------| |
| 2443 | 13200 | Pass 0 code | |
| 2444 | |----------------------------| |
| 2445 | 14000 | Pass 1 initialization | |
| 2446 | | | |
| 2447 | | | |
| 2448 | |----------------------------| |
| 2449 | 16000 | Module count and | |
| 2450 | | module tables | |
| 2451 | |----------------------------| |
| 2452 | 17000 | Library catalog header | |
| 2453 | | read into this block | |
| 2454 | |----------------------------| |
| 2455 | 17600 | OS/8 Field 1 resident | |
| 2456 | ------------------------------ |
| 2457 | |
| 2458 | while ERROR is the local error processing routine, called with a |
| 2459 | pointer to the appropriate error message in the accumulator. |
| 2460 | |
| 2461 | The major pass 1 and pass 2 subroutines, described below, operate on |
| 2462 | the loader internal tables, whose format is presented later in this |
| 2463 | chapter. The subroutines are presented in approximately the order |
| 2464 | that they occur in the source listing. |
| 2465 | |
| 2466 | |
| 2467 | |
| 2468 | |
| 2469 | 3-2 |
| 2470 | \f |
| 2471 | |
| 2472 | |
| 2473 | LOADER PASS 1 (SYMBOL RESOLUTION) |
| 2474 | ------------------------------ |
| 2475 | 00000 | Pass 1 and Pass 2 | FIELD 0 |
| 2476 | | utility routines | |
| 2477 | |----------------------------| |
| 2478 | 01400 | Symbol map printer | |
| 2479 | |----------------------------| |
| 2480 | 02000 | Pass 2 | |
| 2481 | |----------------------------| |
| 2482 | 03200 | Pass 1 symbol collection | |
| 2483 | |----------------------------| |
| 2484 | 04000 | Inter-pass code allocates | |
| 2485 | | storage, builds and writes | |
| 2486 | | Loader Image Header Block. | |
| 2487 | |----------------------------| |
| 2488 | 04600 | Library catalog loads | |
| 2489 | | here in 8K. Unused in | |
| 2490 | | 12K or more. | |
| 2491 | |----------------------------| |
| 2492 | 07200 | Input device handlers | |
| 2493 | |----------------------------| |
| 2494 | 07600 | OS/8 Field 0 resident | |
| 2495 | |----------------------------| |
| 2496 | 10000 | ESD table | FIELD 1 |
| 2497 | | | |
| 2498 | 11400 | | |
| 2499 | |----------------------------| |
| 2500 | 12000 | Symbol table | |
| 2501 | |----------------------------| |
| 2502 | 15400 | Overlay length table | |
| 2503 | |----------------------------| |
| 2504 | 16000 | Module count and module | |
| 2505 | | tables (MCTTBL, MODTBL) | |
| 2506 | |----------------------------| |
| 2507 | 17200 | Loader header | |
| 2508 | |----------------------------| |
| 2509 | 17400 | ESD reference page | |
| 2510 | |----------------------------| |
| 2511 | 17600 | OS/8 Field 1 resident | |
| 2512 | |----------------------------| |
| 2513 | 20000 | Library catalog loads here | FIELD 2 |
| 2514 | | in 12K or more. | |
| 2515 | |----------------------------| |
| 2516 | 25000 | OS/8 BATCH processor if | |
| 2517 | | 12K or more and BATCH | |
| 2518 | | is running | |
| 2519 | ------------------------------ |
| 2520 | |
| 2521 | |
| 2522 | |
| 2523 | |
| 2524 | |
| 2525 | |
| 2526 | |
| 2527 | |
| 2528 | 3-3 |
| 2529 | \f |
| 2530 | |
| 2531 | |
| 2532 | LOADER PASS 2 (LOADER IMAGE BUILDER) |
| 2533 | ----------------------------------- |
| 2534 | 00000 | Utility routines: Symbol table | FIELD 0 |
| 2535 | | look-up, TTY message handler, | |
| 2536 | | OS/8 block I/O, MCTTBL | |
| 2537 | | processor. | |
| 2538 | |---------------------------------| |
| 2539 | 01400 | Routine to print symbol map. | |
| 2540 | |---------------------------------| |
| 2541 | 02000 | Pass 2 | |
| 2542 | |---------------------------------| |
| 2543 | 03200 | Binary buffer #1 | |
| 2544 | | | |
| 2545 | |---------------------------------| |
| 2546 | 05200 | Binary buffer #2 | |
| 2547 | | | |
| 2548 | |---------------------------------| |
| 2549 | 07200 | I/O device handlers | |
| 2550 | |---------------------------------| |
| 2551 | 07600 | OS/8 Field 0 resident | |
| 2552 | |---------------------------------| |
| 2553 | 10000 | RALF module text loads | FIELD 1 |
| 2554 | | here if 8K. | |
| 2555 | |---------------------------------| |
| 2556 | 12000 | Symbol table | |
| 2557 | | | |
| 2558 | |---------------------------------| |
| 2559 | 15400 | Overlay length table | |
| 2560 | |---------------------------------| |
| 2561 | 16000 | MCTTBL and MODTBL | - |
| 2562 | |---------------------------------| | |
| 2563 | 17200 | Binary section table and | > symbol map |
| 2564 | | binary buffer (LDBUFS) table | | output buffer |
| 2565 | |---------------------------------| | |
| 2566 | 17400 | ESD reference page | - |
| 2567 | |---------------------------------| |
| 2568 | 17600 | OS/8 Field 1 resident | |
| 2569 | |---------------------------------| |
| 2570 | 20000 | Binary buffer #3, if >8K | FIELD 2 |
| 2571 | |---------------------------------| |
| 2572 | 22000 | Binary buffer #4, if >8K | |
| 2573 | |---------------------------------| |
| 2574 | 24000 | Binary buffer #5, if >12K | |
| 2575 | |---------------------------------| |
| 2576 | 26000 | Unused | |
| 2577 | |---------------------------------| |
| 2578 | 30000 | RALF module text loads | FIELD 3 |
| 2579 | | here if >12K | |
| 2580 | ----------------------------------- |
| 2581 | |
| 2582 | |
| 2583 | |
| 2584 | |
| 2585 | |
| 2586 | |
| 2587 | 3-4 |
| 2588 | \f |
| 2589 | |
| 2590 | |
| 2591 | SETBPT Sets words BPTR and BPT2 to contain AC and AC+1, |
| 2592 | respectively. |
| 2593 | |
| 2594 | TTYHAN Subroutine to unpack and print a TEXT message on the |
| 2595 | console terminal. TTYHAN is called by: |
| 2596 | |
| 2597 | CDF CURRENT |
| 2598 | CIF 0 |
| 2599 | JMS TTYHAN |
| 2600 | CDF MSGFIELD |
| 2601 | MSG |
| 2602 | |
| 2603 | RTNOS8 Prints a fatal error message and then returns to the |
| 2604 | OS/8 monitor. A pointer to the message must follow |
| 2605 | the JMS RTNOS8. |
| 2606 | |
| 2607 | IOHAN Used to execute all I/O under OS/8. The calling |
| 2608 | sequence is: |
| 2609 | |
| 2610 | TAD (ACARG /Optional |
| 2611 | CDF CURRENT |
| 2612 | CIF 0 |
| 2613 | JMS IOHAN |
| 2614 | ADDR |
| 2615 | ARG1 |
| 2616 | ARG2 |
| 2617 | ARG3 |
| 2618 | |
| 2619 | where ARG1, ARG2 and ARG3 are standard OS/8 device |
| 2620 | handler arguments and ADDR points to a three-word block |
| 2621 | in field 1 which contains the OS/8 unit number in word |
| 2622 | 1, the file length in word 2, and the starting block |
| 2623 | number in word 3. |
| 2624 | |
| 2625 | If ACARG is zero, the indicated I/O operation is |
| 2626 | executed after the handler has been FETCHed, if |
| 2627 | necessary. If ACARG=n (greater than zero), the handler |
| 2628 | for OS/8 unit n is FETCHed, no I/O is done, and the |
| 2629 | four arguments that conclude the calling sequence are |
| 2630 | not needed. |
| 2631 | |
| 2632 | ADVOVR Called to initialize the loader to accept a new input |
| 2633 | module. ADVOVR determines whether a new overlay or |
| 2634 | level is being started by accessing the module count |
| 2635 | table. If so, it sets various pointers and internal |
| 2636 | counters accordingly, rounds the previous overlay to |
| 2637 | terminate on a 200 word boundary, and updates the |
| 2638 | length of the previous level, if necessary, as the |
| 2639 | maximum of its constituent overlay lengths. |
| 2640 | |
| 2641 | NXTOVR Called by ADVOVR when the next input module will be the |
| 2642 | first module in a new overlay. |
| 2643 | |
| 2644 | |
| 2645 | |
| 2646 | 3-5 |
| 2647 | \f |
| 2648 | |
| 2649 | |
| 2650 | SETCNT Initializes the pointers and counters used by ADVOVR. |
| 2651 | SETCNT is called once at the beginning of each pass. |
| 2652 | |
| 2653 | LOOK Executes a symbol look-up in the loader symbol table. |
| 2654 | LOOK is called by: |
| 2655 | |
| 2656 | TAD (Pointer to symbol name in |
| 2657 | RALF ESD format |
| 2658 | JMS LOOK |
| 2659 | RETURN here if not found |
| 2660 | RETURN here if found |
| 2661 | GPTR points to word following entry name |
| 2662 | |
| 2663 | If the symbol is not found, it is inserted into the |
| 2664 | loader symbol table and GPTR is set to point to the |
| 2665 | word following the symbol name. |
| 2666 | |
| 2667 | SYMMAP Produces the symbol map. |
| 2668 | |
| 2669 | PUTSYM Enters an ESD symbol in the loader symbol table. PUTSYM |
| 2670 | calls LOOK to determine whether the symbol is already |
| 2671 | present in the symbol table and, if so, verifies that |
| 2672 | the symbol is not multiply defined. Otherwise, it |
| 2673 | copies the ESD data words into the symbol table entry, |
| 2674 | updates the length of the current overlay by the length |
| 2675 | associated with the symbol, and links the symbol to its |
| 2676 | parent symbol, if any. |
| 2677 | |
| 2678 | FIT Fits a section into core by subtracting its length from |
| 2679 | the amount of core still available and substituting its |
| 2680 | load address for its length in the symbol table. |
| 2681 | |
| 2682 | DO8S, FIT8S Fits an 8-mode section into core by calling FIT and |
| 2683 | then checking for field 1 overflow. |
| 2684 | |
| 2685 | SETREF Extracts data from the ESD table of the current module |
| 2686 | and initializes the ESD reference page at 17400. |
| 2687 | |
| 2688 | BLDTV Builds the transfer vector. A transfer vector entry |
| 2689 | is created for each subroutine in an overlay. This |
| 2690 | entry provides the information that the run-time system |
| 2691 | will require in order to load the overlay containing |
| 2692 | the referenced subroutine. |
| 2693 | |
| 2694 | NEWORG Called whenever an origin is found in an input module, |
| 2695 | to map the location referenced by the origin into a |
| 2696 | block of the loader image file and an address within |
| 2697 | that block. |
| 2698 | |
| 2699 | NEWBB Called whenever a new binary buffer is needed during |
| 2700 | loader image file construction. NEWBB scans a list of |
| 2701 | available buffers and dumps the content of the least |
| 2702 | recently accessed buffer to free up space for new data. |
| 2703 | |
| 2704 | |
| 2705 | 3-6 |
| 2706 | \f |
| 2707 | |
| 2708 | |
| 2709 | MERGE Relocates an input word pair and outputs it to the |
| 2710 | loader image file. |
| 2711 | |
| 2712 | GETCTL Gets a control byte from the input module and incre- |
| 2713 | ments its return address by the content of the control |
| 2714 | byte. |
| 2715 | |
| 2716 | PUTBIN Inserts words, sequentially, into the current binary |
| 2717 | buffer. When the buffer is full, PUTBIN calls NEWBB to |
| 2718 | execute output to the loader image file and supply a |
| 2719 | new buffer. |
| 2720 | |
| 2721 | TXTSCN Called once for each input module. TXTSCN reads and |
| 2722 | relocates an entire input module, executing calls to |
| 2723 | MERGE, PUTBIN and NEWORG as needed. |
| 2724 | |
| 2725 | |
| 2726 | |
| 2727 | SYMBOL TABLE |
| 2728 | |
| 2729 | |
| 2730 | |
| 2731 | The loader symbol table begins at location 12000 and contains room for |
| 2732 | 26 (decimal) permanent system symbol entries and 218 (decimal) user |
| 2733 | entries. Each entry is 7 words long, and provides the name and |
| 2734 | definition of a symbol. The table is organized in buckets according |
| 2735 | to the first character of the symbol, which must be A to Z, #, or |
| 2736 | blank (for blank COMMON). The table of bucket pointers begins at |
| 2737 | location 12000 with the pointer to bucket A, and consists of one word |
| 2738 | per bucket. This word contains a value of zero, if there are no |
| 2739 | symbols in the corresponding bucket, or else the address of the first |
| 2740 | symbol in the bucket. |
| 2741 | |
| 2742 | Symbols within a bucket are arranged in alphabetical order, with each |
| 2743 | symbol entry pointing to the following entry, and the last entry |
| 2744 | pointing to zero. Thus, the symbol table appears as a set of threaded |
| 2745 | lists in core. The format of a symbol table entry is: |
| 2746 | |
| 2747 | |
| 2748 | |
| 2749 | |
| 2750 | |
| 2751 | |
| 2752 | |
| 2753 | |
| 2754 | |
| 2755 | |
| 2756 | |
| 2757 | |
| 2758 | |
| 2759 | |
| 2760 | |
| 2761 | |
| 2762 | |
| 2763 | |
| 2764 | 3-7 |
| 2765 | \f |
| 2766 | |
| 2767 | ------------------------------ |
| 2768 | | Pointer to next symbol in | |
| 2769 | | bucket (zero if none). | WORD 1 |
| 2770 | |----------------------------| |
| 2771 | | S | Y | WORD 2 |
| 2772 | |----------------------------| |
| 2773 | | M | B | WORD 3 |
| 2774 | |----------------------------| |
| 2775 | | O | L | |
| 2776 | |----------------------------| |
| 2777 | | | 3-bit | 4-bit | | |
| 2778 | | * | level | overlay | ** | |
| 2779 | | | # | # | | |
| 2780 | |----------------------------| |
| 2781 | | 9-bit pointer to | | |
| 2782 | | parent symbol | | |
| 2783 | | during pass 1 | | |
| 2784 | | (zero if none). | Field | |
| 2785 | | Trap vector | bits | |
| 2786 | | displacement | | |
| 2787 | | during pass 2. | | |
| 2788 | |----------------------------| |
| 2789 | | ADDRESS | |
| 2790 | | (Length during pass 1) | |
| 2791 | ------------------------------ |
| 2792 | |
| 2793 | |
| 2794 | * 1-bit trap vector flag during pass 1. Error flag during pass 2. |
| 2795 | |
| 2796 | ** 4-bit type code |
| 2797 | 0- undefined |
| 2798 | 1- entry point |
| 2799 | 2- extern |
| 2800 | 3- common sect |
| 2801 | 4- program sect |
| 2802 | 5- multiple entry point |
| 2803 | 6- multiple sect |
| 2804 | 7- SECT8 sect |
| 2805 | 10- COMMZ |
| 2806 | 11- FIELD1 |
| 2807 | 12 to 17- undefined |
| 2808 | |
| 2809 | Several special symbols are created by the loader. The symbol #YLVLn, |
| 2810 | where n is an octal digit, describes overlay level n. This symbol |
| 2811 | table entry contains the length of level n during pass 1 and the |
| 2812 | starting address of level n during pass 2. |
| 2813 | |
| 2814 | The symbol #YTRAP describes the trap vector, a method by which the |
| 2815 | run-time system controls automatic overlaying of user subroutines. |
| 2816 | Four words are allocated in the trap vector for each entry point in |
| 2817 | every overlay except overlay #MAIN. The symbol table entry for #YTRAP |
| 2818 | contains the accumulated length of the trap vector during pass 1 and |
| 2819 | the trap vector starting address during pass 2. |
| 2820 | |
| 2821 | |
| 2822 | |
| 2823 | 3-8 |
| 2824 | \f |
| 2825 | |
| 2826 | |
| 2827 | ESD CORRESPONDENCE TABLE (ESDPG) |
| 2828 | |
| 2829 | |
| 2830 | |
| 2831 | The ESD correspondence table begins at location 17400 and contains 128 |
| 2832 | (decimal) 1-word entries. This table establishes the correspondence |
| 2833 | between the local ESD reference numbers used to reference a symbol |
| 2834 | inside a RALF module, and the address of that symbol in the loader |
| 2835 | symbol table. The nth entry in the ESD correspondence table points to |
| 2836 | the address of ESD symbol n. |
| 2837 | |
| 2838 | |
| 2839 | |
| 2840 | BINARY BUFFER TABLE (LDBUFS) |
| 2841 | |
| 2842 | |
| 2843 | |
| 2844 | The binary buffer table begins at location 17247 and contains from two |
| 2845 | to ten entries, depending upon the amount of memory available. Each |
| 2846 | entry is 4 words in length. The binary buffers function as windows |
| 2847 | into the loader image file, through which the loaded program is |
| 2848 | written onto mass storage. Each binary buffer is 8 pages (4 OS/8 |
| 2849 | blocks) in length. The loader tries to minimize the amount of "window |
| 2850 | turning" necessary to buffer the binary data by keeping a record of |
| 2851 | the last time each buffer was referenced. In this way, when the |
| 2852 | content of a binary buffer must be dumped to make room for new data, |
| 2853 | the loader empties that buffer which was least recently used. |
| 2854 | |
| 2855 | In addition, program loading is overlay oriented such that only one |
| 2856 | overlay is loaded at a time and while any specific overlay is being |
| 2857 | loaded, only origins inside that overlay are legal. |
| 2858 | |
| 2859 | The format of a binary buffer table entry is: |
| 2860 | |
| 2861 | ------------------------------------ |
| 2862 | | Pointer to the binary buffer of | |
| 2863 | | "next earliest reference", i.e., | |
| 2864 | | the youngest buffer older than | WORD 1 |
| 2865 | | this buffer. Contains zero if | |
| 2866 | | this buffer is oldest. | |
| 2867 | |----------------------------------| |
| 2868 | | Loader image block #. Contains | |
| 2869 | | zero if buffer has not been used.| WORD 2 |
| 2870 | |----------------------------------| |
| 2871 | | Blocks left in current overlay | |
| 2872 | | If <4, only part of buffer will | WORD 3 |
| 2873 | | be dumped. | |
| 2874 | |----------------------------------| |
| 2875 | | Page address | Buffer | | |
| 2876 | | of buffer. | field | Unused | WORD 4 |
| 2877 | | | bits | | |
| 2878 | ------------------------------------ |
| 2879 | |
| 2880 | |
| 2881 | |
| 2882 | 3-9 |
| 2883 | \f |
| 2884 | |
| 2885 | |
| 2886 | The number of binary buffers used varies with the amount of memory |
| 2887 | available as follows: |
| 2888 | |
| 2889 | ------------------------------------------- |
| 2890 | MEMORY | NO. OF |
| 2891 | AVAIL | BUFFERS |
| 2892 | -------------------|----------------------- |
| 2893 | 8K | 2 |
| 2894 | 12K | 4 |
| 2895 | 16K | 5 |
| 2896 | 20K | 7 |
| 2897 | 24K | 10 (decimal) |
| 2898 | 28K | 10 (decimal) |
| 2899 | 32K | 10 (decimal) |
| 2900 | ------------------------------------------- |
| 2901 | |
| 2902 | |
| 2903 | |
| 2904 | BINARY SECTION TABLE |
| 2905 | |
| 2906 | |
| 2907 | |
| 2908 | The binary section table overlays the loader image header block |
| 2909 | (described under FRTS) after the latter has been written into the |
| 2910 | loader image file at the beginning of pass 2. Thus, the binary |
| 2911 | section table begins at location 17200 and contains eight 4-word |
| 2912 | entries. Each entry relates the core origin of one of the eight |
| 2913 | overlay levels to that level's position in the loader image file. |
| 2914 | The format of a binary section table entry is: |
| 2915 | |
| 2916 | ----------------------------------- |
| 2917 | | | Field | |
| 2918 | | Unused | of | WORD 1 |
| 2919 | | | level | |
| 2920 | |---------------------------------| |
| 2921 | | Address of level | WORD 2 |
| 2922 | |---------------------------------| |
| 2923 | | Relative block # | WORD 3 |
| 2924 | |---------------------------------| |
| 2925 | | Length (in blocks) | WORD 4 |
| 2926 | ----------------------------------- |
| 2927 | |
| 2928 | |
| 2929 | OVERLAY TABLE (OVLTBL) |
| 2930 | |
| 2931 | |
| 2932 | The overlay table begins at location 15435 and contains room for 113 |
| 2933 | (decimal) 2-word entries. There is one entry for each overlay |
| 2934 | defined, including overlay MAIN, with each entry designating the |
| 2935 | length in words, of the corresponding overlay. The format of an |
| 2936 | overlay table entry is: |
| 2937 | |
| 2938 | |
| 2939 | |
| 2940 | |
| 2941 | 3-10 |
| 2942 | \f |
| 2943 | |
| 2944 | |
| 2945 | OVLTBL |
| 2946 | ----------------------- |
| 2947 | | LEVEL MAIN | |
| 2948 | |---------------------| Negated to indicate |
| 2949 | | LEVEL 1 OVERLAY 1 | last table entry |
| 2950 | |--------/\/----------| / |
| 2951 | . - / |
| 2952 | . | ------------------- / |
| 2953 | . | | HIGH-order bits |/ |
| 2954 | |--------/\/----------| | | of length | WORD 1 |
| 2955 | | LEVEL m OVERLAY n-1 |>----< |-----------------| |
| 2956 | |---------------------| | | LOW-order bits | |
| 2957 | | LEVEL m OVERLAY n | | | of length | WORD 2 |
| 2958 | |---------------------| | ------------------- |
| 2959 | | OVLTBL format | - individual entry (2 words) |
| 2960 | ----------------------- |
| 2961 | |
| 2962 | |
| 2963 | |
| 2964 | MODULE DESCRIPTOR TABLE (MODTBL) |
| 2965 | |
| 2966 | |
| 2967 | |
| 2968 | The module descriptor table begins at location 16172 and contains |
| 2969 | room for 172 (decimal) 3-word entries. Each entry provides the |
| 2970 | information needed to locate an input module. The first MODTBL entry |
| 2971 | corresponds to the library file to be used in building the current |
| 2972 | loader image. Successive entries correspond to input modules and |
| 2973 | appear in the order that the modules were specified by the user, |
| 2974 | (i.e., in ascending order by level, and ascending by overlay within |
| 2975 | any given level.) At the end of pass 1, entries corresponding to |
| 2976 | individual library modules are appended to the end of the table, even |
| 2977 | though the library modules load into level MAIN. The table format is: |
| 2978 | |
| 2979 | |
| 2980 | MODTBL |
| 2981 | -------------------------------- |
| 2982 | | FORLIB.RL or user- | |
| 2983 | | specified library | - |
| 2984 | |------------------------------| | -------------------------- |
| 2985 | | Level MAIN module #1 | | | OS/8 I/O unit # | |
| 2986 | |------------------------------| | |------------------------| |
| 2987 | | Level MAIN module #2 | < | File length (positive) | |
| 2988 | |------------------------------| | |------------------------| |
| 2989 | | Level MAIN module #3 | | | Starting block # | |
| 2990 | |----/\/----------------\/\----| | -------------------------- |
| 2991 | - |
| 2992 | |----/\/----------------\/\----| |
| 2993 | | Level MAIN module n | MODTBL format of |
| 2994 | |------------------------------| individual entry (3 words) |
| 2995 | | Level 1 Overlay 1 module #1 | |
| 2996 | |------------------------------| |
| 2997 | | Level 1 Overlay 1 module #2 | |
| 2998 | |----/\/----------------\/\----| |
| 2999 | |
| 3000 | 3-11 |
| 3001 | \f |
| 3002 | |
| 3003 | |
| 3004 | |----/\/----------------\/\----| |
| 3005 | | Level 1 Overlay 1 module #n | |
| 3006 | |------------------------------| |
| 3007 | | Level 1 Overlay 2 module #1 | |
| 3008 | |----/\/----------------\/\----| |
| 3009 | . |
| 3010 | . |
| 3011 | . |
| 3012 | |----/\/----------------\/\----| |
| 3013 | | Level m Overlay n module #p | |
| 3014 | |------------------------------| |
| 3015 | | Library module #1 | |
| 3016 | |------------------------------| |
| 3017 | | Library module #2 | |
| 3018 | |----/\/----------------\/\----| |
| 3019 | |
| 3020 | MODTBL format |
| 3021 | |
| 3022 | |
| 3023 | |
| 3024 | MODULE COUNT TABLE (MCTTBL) |
| 3025 | |
| 3026 | |
| 3027 | |
| 3028 | The module count table begins at location 16000 and contains room for |
| 3029 | 122 (decimal) 1-word entries that give the (two's complement) module |
| 3030 | count for each overlay level. The table format is: |
| 3031 | |
| 3032 | |
| 3033 | MCTTBL |
| 3034 | ------------------------- |
| 3035 | | LEVEL MAIN | 1-word ENTRIES |
| 3036 | |-----------------------| |
| 3037 | | 0 | |
| 3038 | |-----------------------| |
| 3039 | | LEVEL 1 OVERLAY 1 | |
| 3040 | |-----------------------| |
| 3041 | | LEVEL 1 OVERLAY 2 | |
| 3042 | |-----------------------| |
| 3043 | | LEVEL 1 OVERLAY 3 | |
| 3044 | |----/\/---------\/\----| |
| 3045 | |
| 3046 | |----/\/---------\/\----| |
| 3047 | | LEVEL 1 OVERLAY n | |
| 3048 | |-----------------------| |
| 3049 | | 0 | |
| 3050 | |-----------------------| |
| 3051 | | LEVEL 2 OVERLAY 1 | |
| 3052 | |-----------------------| |
| 3053 | | LEVEL 2 OVERLAY 2 | |
| 3054 | |----/\/---------\/\----| |
| 3055 | |
| 3056 | |
| 3057 | |
| 3058 | |
| 3059 | 3-12 |
| 3060 | \f |
| 3061 | |
| 3062 | |
| 3063 | |
| 3064 | |----/\/---------\/\----| |
| 3065 | | LEVEL 2 OVERLAY n | |
| 3066 | |-----------------------| |
| 3067 | | 0 | |
| 3068 | |-----------------------| |
| 3069 | | LEVEL 3 OVERLAY 1 | |
| 3070 | |----/\/---------\/\----| |
| 3071 | . |
| 3072 | . |
| 3073 | . |
| 3074 | |----/\/---------\/\----| |
| 3075 | | LEVEL m OVERLAY n | |
| 3076 | |-----------------------| |
| 3077 | | 0 | |
| 3078 | |-----------------------| |
| 3079 | | 0 | |
| 3080 | ------------------------- |
| 3081 | |
| 3082 | If an overlay or level is not defined for a specific program, there is |
| 3083 | no module count table entry corresponding to that overlay or level. |
| 3084 | |
| 3085 | The loader image file, produced by the loader and read as input by the |
| 3086 | run-time system, consists of a header block followed by a binary image |
| 3087 | of each level defined in the FORTRAN IV job. |
| 3088 | |
| 3089 | ----------------------------------- ----------- |
| 3090 | | HEADER | LEVEL | LEVEL / / LEVEL | |
| 3091 | | BLOCK | MAIN | 1 \ \ n | |
| 3092 | | | | / / | |
| 3093 | ---------------------------------- ------------ |
| 3094 | |
| 3095 | |
| 3096 | The loader image file header block contains information in the |
| 3097 | following format: |
| 3098 | |
| 3099 | LOCATION CONTENTS |
| 3100 | 0 2 -- Identifies the file as a loader image file. |
| 3101 | 1-2 Initial SWAP arguments to load level MAIN. |
| 3102 | 3-4 Highest address used by core load, including overlays |
| 3103 | but not including OS/8 device handlers. |
| 3104 | 5 Loader version number. |
| 3105 | 6 Double-precision flag. |
| 3106 | 7-46 User overlay information table containing one 4-word |
| 3107 | entry per overlay level (the level MAIN entry is |
| 3108 | ignored) in the following format: |
| 3109 | |
| 3110 | |
| 3111 | |
| 3112 | |
| 3113 | |
| 3114 | |
| 3115 | |
| 3116 | |
| 3117 | |
| 3118 | 3-13 |
| 3119 | \f |
| 3120 | |
| 3121 | |
| 3122 | --------------------------------------- |
| 3123 | | Unused until SWAP time. Must | WORD 1 |
| 3124 | | be positive or zero. | |
| 3125 | |-------------------------------------| |
| 3126 | Load | Page | Bits 4-5 | Field | Bits 9-11 | WORD 2 |
| 3127 | address ---> | bits | unused | bits | unused | |
| 3128 | |-------------------------------------| |
| 3129 | | Block number of this level, | WORD 3 |
| 3130 | | relative to header block. | |
| 3131 | |-------------------------------------| |
| 3132 | | Length of overlays in this level, | WORD 4 |
| 3133 | | in blocks. | |
| 3134 | --------------------------------------- |
| 3135 | |
| 3136 | |
| 3137 | |
| 3138 | |
| 3139 | |
| 3140 | |
| 3141 | |
| 3142 | |
| 3143 | |
| 3144 | |
| 3145 | |
| 3146 | |
| 3147 | |
| 3148 | |
| 3149 | |
| 3150 | |
| 3151 | |
| 3152 | |
| 3153 | |
| 3154 | |
| 3155 | |
| 3156 | |
| 3157 | |
| 3158 | |
| 3159 | |
| 3160 | |
| 3161 | |
| 3162 | |
| 3163 | |
| 3164 | |
| 3165 | |
| 3166 | |
| 3167 | |
| 3168 | |
| 3169 | |
| 3170 | |
| 3171 | |
| 3172 | |
| 3173 | |
| 3174 | |
| 3175 | |
| 3176 | |
| 3177 | 3-14 |
| 3178 | \f |
| 3179 | |
| 3180 | |
| 3181 | CHAPTER 4 |
| 3182 | |
| 3183 | THE FORTRAN IV RUN-TIME SYSTEM |
| 3184 | |
| 3185 | |
| 3186 | The FORTRAN IV run-time system supervises execution of a FORTRAN job |
| 3187 | and provides an I/O interface between the running program and the OS/8 |
| 3188 | operating system. FRTS includes its own loader, which should not be |
| 3189 | confused with LOAD, the system loader. It executes with only one |
| 3190 | overlay, used to restore the resident monitor and effect program |
| 3191 | termination. The run-time system was designed to permit convenient |
| 3192 | modification or enhancement, and it is well documented in the assembly |
| 3193 | language source, available from the Software Distribution Center, |
| 3194 | which includes extensive comments. |
| 3195 | |
| 3196 | One of the most valuable modifications to FRTS provides for the |
| 3197 | inclusion of background (or idle) jobs. When FORTRAN is waiting for |
| 3198 | I/O operations or the FPP to complete execution, the PDP-8 or PDP-12 |
| 3199 | processor is sitting in an idle loop. An idle job may be executed by |
| 3200 | the PDP-8 or PDP-12 CPU during this time, perhaps for the purpose of |
| 3201 | refreshing a CRT display, for example, or monitoring a controlled |
| 3202 | process. To indicate such a job, the idle wait loop must be modified |
| 3203 | to include a reference to the user's PDP-8 routine. The routine #IDLE |
| 3204 | in FRTS must be changed as part of the user's subroutine from |
| 3205 | |
| 3206 | #IDLE, JMP .+4 to #IDLE, SKP |
| 3207 | 0 ADDUSR |
| 3208 | CDF CIF FLDUSR |
| 3209 | JMS I .-2 JMS I .-2 |
| 3210 | |
| 3211 | Devices issuing interrupts may be added to the interrupt skip chain so |
| 3212 | that FORTRAN checks the user's device as well as system devices. The |
| 3213 | original code is: |
| 3214 | |
| 3215 | #INT, JMP .+4 |
| 3216 | 0 |
| 3217 | CDF CIF |
| 3218 | JMS I .-2 |
| 3219 | |
| 3220 | |
| 3221 | and must be changed, as above, to: |
| 3222 | |
| 3223 | #INT, SKP |
| 3224 | ADDUSR |
| 3225 | FLDUSR |
| 3226 | JMS I .-2 |
| 3227 | |
| 3228 | In both cases, ADDUSR should be the address of the user's routine, and |
| 3229 | FLDUSR should be the memory field of the user's routine. |
| 3230 | |
| 3231 | The idle job is initiated by the subroutine HANG in the run-time |
| 3232 | system. Hang should only be called when the FORTRAN program must wait |
| 3233 | for an I/O device flag. The calling sequence is: |
| 3234 | |
| 3235 | |
| 3236 | 4-1 |
| 3237 | \f |
| 3238 | |
| 3239 | |
| 3240 | EXTERN #HANG |
| 3241 | IOF /Important. |
| 3242 | CDF n /Where n is current field. |
| 3243 | CIF 0 |
| 3244 | JMS% HANG+1 |
| 3245 | ADDRSS |
| 3246 | /Return here with interrupts OFF |
| 3247 | /When device flag is raised. |
| 3248 | |
| 3249 | HANG, ADDR #HANG |
| 3250 | |
| 3251 | The word ADDRSS must point to a location in page 400 of the run-time |
| 3252 | system which must normally contain a JMP DISMIS. Three such locations |
| 3253 | have been provided for the user at #DISMS, #DISMS+1, and #DISMS+2. The |
| 3254 | selected location must be the location via which the interrupt caused |
| 3255 | by the desired flag is dismissed. No two flag routines should use the |
| 3256 | same dismiss location. The following program example illustrates |
| 3257 | these calling conventions. This routine may be used to drive a |
| 3258 | Teletype terminal via the PT08 option. |
| 3259 | |
| 3260 | EXTERN #ONQI |
| 3261 | EXTERN #DISMS |
| 3262 | FIELD1 GETCH /JMS GETCH GETS A CHAR |
| 3263 | 0 /GETCH RUNS IN FIELD I ONLY |
| 3264 | ISZ FIRST |
| 3265 | JMP NOTFST |
| 3266 | JMS% ONQI+1 |
| 3267 | KSF1 |
| 3268 | ADDR KSFSUB |
| 3269 | TAD DISMIS+1 /SET UP TO CALL HANG |
| 3270 | DCA HNGLOC |
| 3271 | NOTFST, IOF |
| 3272 | TAD INCHR |
| 3273 | SZA CLA |
| 3274 | JMP GOT1 |
| 3275 | CIF 0 |
| 3276 | JMS% HANG+1 /NO CHAR READY: HANG |
| 3277 | HNGLOC, 0 |
| 3278 | /HANG RETURNS W/ IOF |
| 3279 | GOT1, TAD INCHR |
| 3280 | DCA FIRST |
| 3281 | DCA INCHR |
| 3282 | TAD FIRST |
| 3283 | ION |
| 3284 | JMP% GETCH |
| 3285 | /INTERRUPT ROUTINE - |
| 3286 | KSFSUB, 0 /CALLED AS SUBROUTINE |
| 3287 | KRB1 |
| 3288 | DCA INCHR |
| 3289 | CDF CIF 0 |
| 3290 | JMP% DISMIS+1 /RETURN TO SYSTEM LOCATION |
| 3291 | /CONTAINING "JMP DISMIS" |
| 3292 | INCHR, 0 |
| 3293 | ONQI, ADDR #ONQI |
| 3294 | |
| 3295 | 4-2 |
| 3296 | \f |
| 3297 | |
| 3298 | |
| 3299 | HANG, ADDR #HANG |
| 3300 | DISMIS, ADDR #DISMS |
| 3301 | FIRST, -1 |
| 3302 | |
| 3303 | In most cases, it is easier to include references to the FORLIB module |
| 3304 | ONQI for adding a handler to the interrupt skip chain and ONQB for |
| 3305 | adding a job to the idle chain, instead of trying to modify #IDLE and |
| 3306 | #INT. ONQB provides slots for up to 9 idle jobs to be executed |
| 3307 | round-robin, and ONQI provides for up to 9 user flags to be tested on |
| 3308 | program interrupts. |
| 3309 | |
| 3310 | FRTS entry points are listed, along with the core map, on the |
| 3311 | following pages. The FRTS calling sequence must be observed in any |
| 3312 | user subroutine. The formal calling sequence is illustrated below. In |
| 3313 | general, it can be used exactly as illustrated, changing only the |
| 3314 | section, entry, base page, index register and return location names. |
| 3315 | |
| 3316 | |
| 3317 | |
| 3318 | FRTS CALLING SEQUENCE |
| 3319 | |
| 3320 | |
| 3321 | |
| 3322 | SECT EXAMPL /Section name. Your module may |
| 3323 | /require another section pseudo-op |
| 3324 | /such as FIELD1 or SECT8. |
| 3325 | JA #EXSRT /Jump to start of subroutine |
| 3326 | /Use # for first character |
| 3327 | TEXT +EXAMPL+ /6 character section name for |
| 3328 | /error traceback (optional) |
| 3329 | EXAMXR, SETX XREXAM /Set up index registers |
| 3330 | /for this subroutine |
| 3331 | SETB BPEXAM /and its base page. |
| 3332 | BPEXAM, F 0.0 /Base page |
| 3333 | XREXAM, F 0.0 /Index registers 0-2 |
| 3334 | F 0.0 /Index registers 3-5 (optional) |
| 3335 | EXTMP1, F 0.0 /Space between index registers |
| 3336 | EXTMP2, F 0.0 /and the ORG for temporary |
| 3337 | EXTMP3, F 0.0 /storage (optional) |
| 3338 | ORG 10*3+BPEXAM /Location 30 of base page |
| 3339 | FNOP /Force a two-word instruction |
| 3340 | JA EXAMXR /Jump to base page for |
| 3341 | /return to calling program |
| 3342 | 0 /Force a two-word instruction |
| 3343 | EXMRTN, JA . /Will be replaced by return jump |
| 3344 | BASE 0 /Caller's base page |
| 3345 | #EXSRT, STARTD /Start of subroutine |
| 3346 | FLDA 10*3 /Get return jump from caller's |
| 3347 | /base page |
| 3348 | FSTA EXMRTN /Save in return location for |
| 3349 | /this routine |
| 3350 | FLDA 0 /Location 0 of caller's routine |
| 3351 | /is a pointer to the argument list |
| 3352 | SETX XREXAM /Change to EXAMPL's index registers |
| 3353 | |
| 3354 | 4-3 |
| 3355 | \f |
| 3356 | |
| 3357 | |
| 3358 | SETB BPEXAM /Change to EXAMPL's base page |
| 3359 | BASE BPEXAM |
| 3360 | FSTA BPEXAM /Save the pointer |
| 3361 | LDX 1,1 /Set up index register 1 |
| 3362 | FLDA% BPEXAM, 1 /Get address of argument list |
| 3363 | FSTA EXTMP1 /Save the addresses |
| 3364 | FLDA% BPEXAM, 1+ /of all passed arguments |
| 3365 | FSTA EXTMP2 |
| 3366 | FLDA% BPEXAM, 1+ |
| 3367 | FSTA EXTMP3 /Continue for all arguments |
| 3368 | . /to be picked up |
| 3369 | . |
| 3370 | . |
| 3371 | STARTF /Start three-word instructions |
| 3372 | FLDA% EXTMP1 |
| 3373 | . |
| 3374 | . |
| 3375 | . |
| 3376 | FLDA% EXTMP2 |
| 3377 | . |
| 3378 | . |
| 3379 | . /Continue to get arguments |
| 3380 | . /as required in routine |
| 3381 | JA EXMRTN /Exit when done |
| 3382 | |
| 3383 | |
| 3384 | |
| 3385 | RTS ENTRY POINT USEAGE AND COMMENTS |
| 3386 | |
| 3387 | #UE TRAP3 #UE /Produces USER ERROR error message. |
| 3388 | |
| 3389 | #ARGER or TRAP4 #ARGER /Produces BAD ARG error message. |
| 3390 | #ARGERR |
| 3391 | |
| 3392 | #READO TRAP3 #READO /Initializes |
| 3393 | JA UNITNO /formatted |
| 3394 | JA FORMAT /read operation. |
| 3395 | |
| 3396 | #WRITO TRAP3 #WRITO /Initializes |
| 3397 | JA UNITNO /formatted |
| 3398 | JA FORMAT /write operation. |
| 3399 | |
| 3400 | #RUO TRAP3 #RUO /Initializes unformatted |
| 3401 | JA UNITNO /read operation. |
| 3402 | |
| 3403 | #WUO TRAP3 #WUO /Initializes unformatted |
| 3404 | JA UNITNO /write operation. |
| 3405 | |
| 3406 | #RDAO TRAP3 #RDAO /Initializes |
| 3407 | JA UNITNO /direct access |
| 3408 | JA RECNO /read operation. |
| 3409 | |
| 3410 | |
| 3411 | |
| 3412 | |
| 3413 | 4-4 |
| 3414 | \f |
| 3415 | |
| 3416 | |
| 3417 | #WDAO TRAP3 #WDAO /Initializes |
| 3418 | JA UNITNO /direct access |
| 3419 | JA RECNO /write operation. |
| 3420 | |
| 3421 | #RFSV TRAP3 #RFSV /Passes a variable to or from the read/ |
| 3422 | /write processors via the floating AC. |
| 3423 | |
| 3424 | #RENDO TRAP3 #RENDO /Terminates a read/write operation. |
| 3425 | |
| 3426 | #ENDF FLDA UNITNO /Executes an |
| 3427 | TRAP3 #ENDF /end file, |
| 3428 | #REW or TRAP3 #REW /rewind, |
| 3429 | #BAK or TRAP3 #BAK /backspace (depending upon the entry used) |
| 3430 | /on the referenced I/O unit. |
| 3431 | |
| 3432 | #DEF TRAP3 #DEF /Opens a file |
| 3433 | JA UNITNO /for direct access I/O. |
| 3434 | JA RECORDS |
| 3435 | JA FPNPR /(FPP numbers per record) |
| 3436 | JA VARIABLE /Refer to DEFINE FILE statement |
| 3437 | |
| 3438 | #EXIT JSR #EXIT /Terminates current FORTRAN IV job. |
| 3439 | |
| 3440 | #SWAP TRAP3 #SWAP /Reads overlay OVLY into level LVL and |
| 3441 | ADDR /jumps to ADR. ADDR is given by: |
| 3442 | /ADDR=4000000*OVLY+100000*LVL+ADR |
| 3443 | |
| 3444 | #8OR12 /=00000001 if the CPU is a PDP-12. |
| 3445 | |
| 3446 | #IDLE Address of background job, used by ONQB. Contains: |
| 3447 | |
| 3448 | JMP I (NULJOB /Replace by SKP |
| 3449 | 0 /Replace by addr of background job |
| 3450 | CDF CIF 0 /Replace by field of background job |
| 3451 | JMS I .-2 |
| 3452 | JMP .-4 |
| 3453 | |
| 3454 | |
| 3455 | |
| 3456 | CORE LAYOUT OF FRTS |
| 3457 | |
| 3458 | NON-FPP FPP (Same as non-FPP |
| 3459 | unless indicated) |
| 3460 | ----------------------------------- |
| 3461 | 0000 | Page zero (0120-0134 free) | |
| 3462 | |---------------------------------| |
| 3463 | 0200 | Most entry points, character | |
| 3464 | | I/O handlers, interrupt | |
| 3465 | | service, and HANG routine | |
| 3466 | |---------------------------------| |
| 3467 | 0600 | Format decoder; A, H, and ' | |
| 3468 | | format processors, and EXIT | |
| 3469 | |------\/\---------------/\/------| |
| 3470 | |
| 3471 | |
| 3472 | 4-5 |
| 3473 | \f |
| 3474 | |
| 3475 | |
| 3476 | |------\/\---------------/\/------| |
| 3477 | 1400 | REWIND, ENDFILE, BACKSPACE and | |
| 3478 | | general unit initialization | |
| 3479 | | DATABL table (3wds/unit) | |
| 3480 | |---------------------------------| |
| 3481 | 2000 | I, E, F and G output | |
| 3482 | |---------------------------------| |
| 3483 | 2400 | I, E, F and G input | |
| 3484 | |---------------------------------| |
| 3485 | 2600 | X, L and T formats and | |
| 3486 | | GETHND routine | |
| 3487 | |---------------------------------| |
| 3488 | 3000 | Char in and char out routines | |
| 3489 | | including OS/8 packing, editing | |
| 3490 | | and forms control | |
| 3491 | |---------------------------------| |
| 3492 | 3400 | Binary and D. A. I/O, and | |
| 3493 | | DEFINE FILE processor | |
| 3494 | |---------------------------------| |
| 3495 | 3600 | Overlay loader | |
| 3496 | |---------------------------------| |
| 3497 | 4000 | Input line buffer, overlay | |
| 3498 | | and DSRN tables, FORMAT | |
| 3499 | | parenth pushdown list, /P | |
| 3500 | | processor and init flag clear | |
| 3501 | |---------------------------------| |
| 3502 | 4400 | Floating-point utilities (shift,| |
| 3503 | | add, etc.) used even w/FPP | |
| 3504 | |---------------------------------| |
| 3505 | 4600 | Error routine and messages | |
| 3506 | |---------------------------------| |
| 3507 | 5200 | OS/8 handler area and part of | |
| 3508 | | FRTS loader initialization | |
| 3509 | |---------------------------------|----------------------------- |
| 3510 | 5600 | FPP simulator | FPP start-up and trap | |
| 3511 | | | routines | |
| 3512 | | |----------------------------| |
| 3513 | 6000 | | B and D format I/O | |
| 3514 | |---------------------------------|----------------------------| |
| 3515 | 6600 | Floating-point package and | Floating-point package | |
| 3516 | | part of LPT ring buffer | (never used) and part of | |
| 3517 | | | LPT ring buffer | |
| 3518 | |---------------------------------|----------------------------- |
| 3519 | 7400 | Most of LPT ring buffer | |
| 3520 | |---------------------------------| |
| 3521 | 7600 | OS/8 handler and field | |
| 3522 | | 0 resident | |
| 3523 | |---------------------------------| |
| 3524 | 10000 | OS/8 User Service Routine | |
| 3525 | |---------------------------------| |
| 3526 | 12000 | FRTS loader tables, IONTBL | Locations 12000 to 17400 are |
| 3527 | | | overlayed at execution time |
| 3528 | |------\/\---------------/\/------| |
| 3529 | |
| 3530 | |
| 3531 | 4-6 |
| 3532 | \f |
| 3533 | |
| 3534 | |
| 3535 | |------\/\---------------/\/------| |
| 3536 | 12200 | FRTS loader: main flow | |
| 3537 | |---------------------------------| |
| 3538 | 12400 | program start-up (1) | |
| 3539 | |---------------------------------| |
| 3540 | 12600 | initialize and | |
| 3541 | | configure system | |
| 3542 | |---------------------------------| |
| 3543 | 13000 | Load OS/8 handlers and assign | |
| 3544 | | unit numbers to OS/8 files | |
| 3545 | |---------------------------------| |
| 3546 | 13400 | Utility and error routines, | |
| 3547 | | error messages | |
| 3548 | 14000 | | |
| 3549 | |---------------------------------| |
| 3550 | 15600 | FPP start-up and trap routines | Locations 14000 to 16777 are |
| 3551 | |---------------------------------| used to save lower field 0 |
| 3552 | 16000 | B and D format I/O | during loading of device |
| 3553 | |---------------------------------| handlers and file |
| 3554 | 16600 | EAE Floating-point package | specifications |
| 3555 | |---------------------------------| |
| 3556 | 17400 | Termination routine | Locations 17400 to 17777 are |
| 3557 | |---------------------------------| written on SYS block 37 |
| 3558 | 17600 | OS/8 field 1 resident | before program load and |
| 3559 | |---------------------------------| restored on termination |
| 3560 | |
| 3561 | |
| 3562 | |
| 3563 | |
| 3564 | |
| 3565 | #INT /Address of user interrupt location, used by ONQI: |
| 3566 | |
| 3567 | JMP .+4 /Replace with SKP |
| 3568 | 0 /Replace with address of interrupt |
| 3569 | processor |
| 3570 | CDF CIF 0 /Replace with field of interrupt |
| 3571 | processor |
| 3572 | JMS I .-2 |
| 3573 | |
| 3574 | #DISMS /Addresses first of three JMP DISMIS instructions |
| 3575 | for use by specialized I/O routines. |
| 3576 | |
| 3577 | #HANG /Addresses I/O dismiss routine. |
| 3578 | |
| 3579 | #RETRN /Provides return from TRAP3. |
| 3580 | |
| 3581 | |
| 3582 | |
| 3583 | |
| 3584 | ------------------------ |
| 3585 | (1) Program start-up moves OS/8 handler to top of core, writes field |
| 3586 | 1 resident onto SYS, and termination routine goes to FRTS to load |
| 3587 | program. |
| 3588 | |
| 3589 | |
| 3590 | 4-7 |
| 3591 | \f |
| 3592 | |
| 3593 | |
| 3594 | DSRN TABLE |
| 3595 | |
| 3596 | |
| 3597 | |
| 3598 | The DSRN table controls files and I/O devices used under OS/8 FORTRAN |
| 3599 | IV ASCII, binary and direct access I/O operations, including |
| 3600 | BACKSPACE, REWIND, and END FILE operations. The exact meaning of the |
| 3601 | initials DSRN is one of the great, unanswered questions of FORTRAN IV |
| 3602 | development and, as such, has considerable historical interest. The |
| 3603 | DSRN table provides room for 9 entries; each entry is 9 words in |
| 3604 | length, and contains the following data: |
| 3605 | |
| 3606 | WORD 1: (HAND) Handler entry point. If this value is positive, the |
| 3607 | I/O device handler is a FORTRAN internal (character-oriented) |
| 3608 | handler, and the remainder of the DSRN table entry is |
| 3609 | ignored. If the value is negative, the handler is an OS/8 |
| 3610 | device handler whose entry point is the two's complement of |
| 3611 | the value. Entry points always fall in the range [7607, |
| 3612 | 7777] for resident handlers or [5200, 5377] for non-resident |
| 3613 | handlers. Space for non-resident handlers is allocated |
| 3614 | downward from the top of memory, and the handlers are moved |
| 3615 | into locations 5200 to 5577 before being called. |
| 3616 | |
| 3617 | WORD 2: (HCODEW) Handler code word. Bits 0-4 of this word specify |
| 3618 | the page into which the device handler was loaded, while bits |
| 3619 | 6-8 specify the memory field. If all of bits 0-8 are zero, |
| 3620 | the handler is permanently resident. When any of these bits |
| 3621 | are non-zero, the data is used to determine which handler, if |
| 3622 | any, currently occupies locations 5200-5577. This eliminates |
| 3623 | unnecessarily moving the content of memory. Bit 10 is set if |
| 3624 | forms control has been inhibited on the I/O unit. Bit 11 is |
| 3625 | set if the device handler can execute with the interrupt |
| 3626 | system enabled. The data in bits 10 and 11 is obtained from |
| 3627 | the IOWTBL table in the FRTS loader. |
| 3628 | |
| 3629 | WORD 3: (BADFLD) Buffer address and field. Bits 0-4 address the |
| 3630 | memory page at which the I/O buffer for this unit begins, |
| 3631 | while bits 6-8 specify the memory field. Unlike the FORTRAN |
| 3632 | internal I/O unit buffers, OS/8 device handler buffers always |
| 3633 | occupy two full pages of memory. Buffer space is allocated |
| 3634 | upward from the top of the FORTRAN program. |
| 3635 | |
| 3636 | WORD 4: (CHRPTR) Character pointer. |
| 3637 | |
| 3638 | WORD 5: (CHRCTR) Character counter. Words 4 and 5 of each DSRN table |
| 3639 | entry define the current character/position in the I/O buffer |
| 3640 | as follows: |
| 3641 | |
| 3642 | |
| 3643 | |
| 3644 | |
| 3645 | |
| 3646 | |
| 3647 | |
| 3648 | |
| 3649 | 4-8 |
| 3650 | \f |
| 3651 | |
| 3652 | |
| 3653 | Value of Character Next value Next value Special |
| 3654 | CHRCTR position of CHRCTR of CHRPTR Conditions |
| 3655 | ---------------------------------------------------------------------- |
| 3656 | | Bits 4-11 of word | | | Refresh buffer if |
| 3657 | -3 | addressed by | -2 | CHRPTR + 1 | input operation and |
| 3658 | | CHRPTR | | | CHRPTR mod 256=0 |
| 3659 | | | | | |
| 3660 | -2 | " | -1 | " | none |
| 3661 | | | | | |
| 3662 | -1 | Bits 0-3 of words | | | |
| 3663 | | addressed by | | | Dump buffer if |
| 3664 | | CHRPTR-2 and | -3 | CHRPTR | output operation |
| 3665 | | CHRPTR-1 | | | and CHRPTR mod |
| 3666 | | | | | 256=0 |
| 3667 | | | | | |
| 3668 | ---------------------------------------------------------------------- |
| 3669 | |
| 3670 | |
| 3671 | WORD 6: (STBLK) Starting block of file. |
| 3672 | |
| 3673 | WORD 7: (RELBLIC) Current relative block of file. That is, block to |
| 3674 | be accessed next. |
| 3675 | |
| 3676 | WORD 8: (TOTBLK) Length of file in blocks. |
| 3677 | |
| 3678 | WORD 9: (FFLAGS) Status flags: |
| 3679 | |
| 3680 | Bit 0 - Has been written flag. Set to 1 if unit has |
| 3681 | received output since last REWIND. |
| 3682 | |
| 3683 | Bit 1 - Formatted I/O flag. Set to 1 if an ASCII I/O |
| 3684 | operation has occurred since last REWIND. |
| 3685 | |
| 3686 | Bit 2 - Unformatted I/O flag. Set to 1 if a binary or |
| 3687 | direct access I/O operation has occurred since last |
| 3688 | REWIND. Bits 1 and 2 are never set simultaneously. |
| 3689 | |
| 3690 | Bit 11- END FILEd flag. Set to 1 if unit has been END |
| 3691 | FILEd. Bit 11 is not cleared by a REWIND. |
| 3692 | |
| 3693 | When any active unit is selected for an I/O operation, the DSRN table |
| 3694 | entry for that unit is moved into 9 words on page 0. These 9 words |
| 3695 | are tagged with the labels cited above. Upon completion of the I/O |
| 3696 | operation, the 9 words are moved from page 0 back into the DSRN table. |
| 3697 | |
| 3698 | |
| 3699 | |
| 3700 | |
| 3701 | |
| 3702 | |
| 3703 | |
| 3704 | |
| 3705 | |
| 3706 | |
| 3707 | |
| 3708 | 4-9 |
| 3709 | \f |
| 3710 | |
| 3711 | |
| 3712 | /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 3 |
| 3713 | |
| 3714 | /PAGE ZERO FOR FORTRAN IV RTS |
| 3715 | |
| 3716 | 0000 *0 /INTERRUPT STUFF |
| 3717 | 00000 0000 0 |
| 3718 | 00001 5402 JMP I .+1 |
| 3719 | 00002 0400 INTRPT |
| 3720 | 00003 5165 LPGET, LPBUFR /LINE PRINTER RING BUFFER FETCH |
| 3721 | 00004 0000 TOCHR, 0 /TELETYPE STATUS WORD |
| 3722 | 00005 0000 KBDCHR, 0 /KEYBOARD INPUT CHARACTER |
| 3723 | 00006 0000 POCHR, 0 /P.T. PUNCH COMPLETION FLAG |
| 3724 | 00007 0000 RDRCHR, 0 /P.T. READER STATUS |
| 3725 | 00010 0000 FMTPXR, 0 /XR USED TO INDEX FORMAT PARENTH |
| 3726 | 00011 3777 INXR, INBUFR-1 /XR USED TO GET CHARS FROM INPUT |
| 3727 | 00012 0000 XR, 0 |
| 3728 | 00013 0000 XR1, 0 |
| 3729 | |
| 3730 | 0016 *16 |
| 3731 | 00016 0000 VEOFSW, 0 /USED BY "EOFCHK" TO STORE VARIABLE ADDRESS |
| 3732 | 00017 0000 0 /*K* MUST BE IN AUTO - XR |
| 3733 | 00020 0000 T, 0 /TEMPORARY |
| 3734 | 00021 0000 DFLG, 0 /0 = F.P., 1 = D.P. |
| 3735 | 00022 0000 INST, 0 /CURRENT INSTRUCTION WORD |
| 3736 | |
| 3737 | /IOH PAGE ZERO LOCATIONS |
| 3738 | |
| 3739 | 00023 0000 RWFLAG, 0 /READ/WRITE FLAG |
| 3740 | 00024 0000 FMTTYP, 0 /TYPE OF CONVERSION BEING DONE |
| 3741 | 00025 0000 EOLSW, 0 /EOL SW ON INPUT - CHAR POS ON OUT |
| 3742 | 00026 0000 N, 0 /REPEAT FACTOR |
| 3743 | 00027 0000 W, 0 /FIELD WIDTH |
| 3744 | 00030 0000 D, 0 /NUMBER OF PLACES AFTER DECIMAL |
| 3745 | 00031 0300 DATCDF, 0 /SUBROUTINE TO CHANGE DATA FIELD |
| 3746 | 00032 0000 DATAF, 0 /CONTAINS VARIOUS CDF'S |
| 3747 | 00033 5431 JMP I DATCDF /RETURN |
| 3748 | 00034 5013 ERR, ERROR /POINTER TO ERROR ROUTINE |
| 3749 | 00035 0000 FATAL, 0 /FATAL ERROR FLAG - 0=FATAL |
| 3750 | 00036 5000 MCDF, MAKCDF |
| 3751 | |
| 3752 | /FPP PARAMETER TABLE LOCATIONS: |
| 3753 | |
| 3754 | 00037 0000 APT, 0 /VARIOUS FIELD BITS FOR FPP |
| 3755 | 00040 5313 PC, DPTEST /FPP PROGRAM COUNTER |
| 3756 | 00041 0000 XRBASE, 0 /FPP INDEX REGISTER ARRAY ADDRESS |
| 3757 | 00042 0000 BASADR, 0 /FPP BASE PAGE ADDRESS |
| 3758 | 00043 0000 ADR, 0 /ADDRESS TEMPORARY |
| 3759 | 00044 0000 ACX, 0 |
| 3760 | 00045 0000 ACH, 0 /*** FLOATING ACCUMULATOR *** |
| 3761 | 00046 0000 ACL, 0 |
| 3762 | 00047 0000 EAC1, 0 |
| 3763 | 00050 0000 EAC2, 0 /** FOR EXTENDED PRECISION OPTION ** |
| 3764 | 00051 0003 EAC3, 0 |
| 3765 | |
| 3766 | |
| 3767 | 4-10 |
| 3768 | \f |
| 3769 | |
| 3770 | |
| 3771 | /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 4 |
| 3772 | |
| 3773 | /FLOATING POINT PACKAGE LOCATIONS |
| 3774 | |
| 3775 | 00052 0000 AC0, 0 |
| 3776 | 00053 0000 AC1, 0 /FLOATING AC OVERFLOW WORD |
| 3777 | 00054 0000 AC2, 0 /OPERAND OVFLOW WORD |
| 3778 | 00055 0000 OPX, 0 |
| 3779 | 00056 0000 OPH, 0 /*** FLOATING OPERAND REGISTER *** |
| 3780 | 00057 0000 OPL, 0 |
| 3781 | |
| 3782 | /RTS I/O SYSTEM LOCATIONS |
| 3783 | |
| 3784 | 00060 0000 FMTBYT, 0 /FORMAT BYTE POINTER |
| 3785 | 00061 0000 IFLG, 0 /I FORMAT FLAG |
| 3786 | 00062 0000 GFLG, 0 /G FORMAT FLAG |
| 3787 | 00063 0000 EFLG, 0 /E FORMAT FLAG - SOMETIMES ON FOR |
| 3788 | 00064 0000 OD, 0 |
| 3789 | 00065 0000 SCALE, 0 |
| 3790 | 00066 0000 PFACT, 0 /P-SCALE FACTOR |
| 3791 | 00067 0000 PFACTX, 0 /TEMP FOR PFACT |
| 3792 | 00070 0000 INESW, 0 /EXPONENT SWITCH |
| 3793 | 00071 0000 CHCH, 0 |
| 3794 | 00072 0000 FMTNUM, 0 /CONTAINS ACCUMULATED NUMERIC VALUE |
| 3795 | 00073 0000 CTCINH, 0 /^C INHIBIT FLAG |
| 3796 | 00074 0320 PTTY, TTY /POINTER TO TTY HANDLER - USED BY |
| 3797 | 00075 0000 0 / SO FORMS CONTROL WILL WORK ON |
| 3798 | 00076 6001 FPNXT, ICYCLE /USED AS INTERPRETER ADDRESS IF |
| 3799 | |
| 3800 | /DSRN IMAGE |
| 3801 | |
| 3802 | 00077 0000 HAND, 0 /HANDLER ENTRY POINT |
| 3803 | 00100 0000 HCODEW, 0 /HANDLER LOAD ADDR & FIELD + IOFFL |
| 3804 | 00101 0000 BADFLD, 0 /BUFFER ADDRESS AND FIELD |
| 3805 | 00102 0000 CHRPTR, 0 /ACTUALLY A WORD POINTER |
| 3806 | 00103 0000 CHRCTR, 0 /COUNTER - RANGES FROM -3 TO -1 |
| 3807 | 00104 0000 STBLK, 0 /STARTING BLOCK OF FILE |
| 3808 | 00105 0000 RELBLK, 0 /CURRENT RELATIVE BLOCK NUMBER |
| 3809 | 00106 0000 TOTBLK, 0 /LENGTH OF FILE |
| 3810 | 00107 0000 FFLAGS, 0 /FILE FLAGS: |
| 3811 | /BIT 0 - "HAS BEEN WRITTEN" FLAG |
| 3812 | /BITS 1-2 - FORMATTED/UNFORMATTED |
| 3813 | /BIT 11 - "END-FILED" FLAG |
| 3814 | 00110 0000 BUFFLD, 0 /ROUTINE TO SET DF TO BUFFER FIELD |
| 3815 | 00111 7402 BUFCDF, HLT |
| 3816 | 00112 5510 JMP I BUFFLD |
| 3817 | 00113 0000 FGPBF, 0 /THESE THREE WORDS ARE USED |
| 3818 | 00114 0000 BIOPTR, 0 /TO FETCH AND STORE FLOATING POINT |
| 3819 | 00115 0000 FEXIT /FROM RANDOM MEMORY |
| 3820 | 0200 PAGE |
| 3821 | |
| 3822 | |
| 3823 | |
| 3824 | |
| 3825 | |
| 3826 | 4-11 |
| 3827 | \f |
| 3828 | |
| 3829 | |
| 3830 | /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 5 |
| 3831 | |
| 3832 | /STARTUP CODE |
| 3833 | |
| 3834 | 00200 2203 FTEMP2, ISZ .+3 /ALSO USED AS I/O F.P. TEMPORARY |
| 3835 | 00201 6213 CDF CIF 10 |
| 3836 | 00202 5603 JMP I .+1 |
| 3837 | 00203 2200 VDATE, RTSLDR /USED TO STORE OS/8 DATE |
| 3838 | |
| 3839 | /RTS ENTRY POINTS - "VERSION INDEPENDENT" |
| 3840 | |
| 3841 | 00204 5777 VUERR, JMP I (USRERR /USER ERROR |
| 3842 | /** LOADER MUST DEFINE #ARGER AS |
| 3843 | 00205 4434 VARGER, JMS I ERR /LIBRARY ARGUMENT ERROR |
| 3844 | 00206 2023 VRENDO, ISZ RWFLAG /END OF I/O LIST |
| 3845 | 00207 5634 VRFSV, JMP I GETLMN /I/O LIST ARG ENTRY - COROUTINE |
| 3846 | 00210 5776 VBAK, JMP I (BKSPC /"BACKSPACE" ROUTINE |
| 3847 | 00211 5775 VENDF, JMP I (ENDFL /"END FILE" ROUTINE |
| 3848 | 00212 5774 VREW, JMP I (RWIND /"REWIND" ROUTINE |
| 3849 | 00213 5773 VDEF, JMP I (DFINE /"DEFINE FILE" ROUTINE |
| 3850 | 00214 7330 VWUO, AC4000 /UNFORMATTED WRITE |
| 3851 | 00215 5772 VRUO, JMP I (RWUNF /UNFORMATTED READ |
| 3852 | 00216 7330 VWDAO, AC4000 /DIRECT ACCESS WRITE |
| 3853 | 00217 5771 VRDAO, JMP I (RWDACC /DIRECT ACCESS READ |
| 3854 | 00220 7330 VWRITO, AC4000 /FORMATTED (ASCII) WRITE |
| 3855 | 00221 5770 VREADO, JMP I (RWASCI /FORMATTED (ASCII) READ |
| 3856 | 00222 5767 VSWAP, JMP I (SWAP /OVERLAY PROCESSOR |
| 3857 | 00223 3000 VEXIT, TRAP3; CALXIT /"STOP" ROUTINE - ENTERED IN FPP |
| 3858 | 00224 1317 |
| 3859 | 00225 0000 V8OR12, 0;0 /0;1 IF CPU IS A PDP-12 |
| 3860 | 00226 0000 |
| 3861 | 00227 5766 VBACKG, JMP I (NULLJB /BACKGROUND JOB DISPATCHER |
| 3862 | 00230 0000 0 |
| 3863 | 00231 6203 CDF CIF 0 /USED BY ROUTINE "ONQB" IN LIBRARY |
| 3864 | 00232 4630 JMS I .-2 |
| 3865 | 00233 5227 JMP VBACKG |
| 3866 | |
| 3867 | /IOH GET VARIABLE ROUTINE. |
| 3868 | /THIS ROUTINE MAKES THE FORMATTED I/O PROCESSOR AND THE |
| 3869 | /PROGRAM CO-ROUTINES (DEF(COROUTINE): 2 ROUTINES EACH |
| 3870 | / IS A SUBROUTINE). ON ENTRY FAC=INPUT NUMBER |
| 3871 | /IF I/O IS A READ, ON RETURN FAC=OUTPUT NUMBER IF I/O |
| 3872 | |
| 3873 | 00234 0000 GETLMN, 0 |
| 3874 | 00235 5577 VRETRN, JMP I [RETURN |
| 3875 | |
| 3876 | |
| 3877 | |
| 3878 | |
| 3879 | |
| 3880 | |
| 3881 | |
| 3882 | |
| 3883 | |
| 3884 | |
| 3885 | 4-12 |
| 3886 | \f |
| 3887 | |
| 3888 | |
| 3889 | All FORTRAN IV mass storage I/O is performed in terms of OS/8 blocks, |
| 3890 | including direct access I/O. Hence, all FORTRAN IV files conform to |
| 3891 | OS/8 standard ASCII file format. When a formatted READ or WRITE is |
| 3892 | requested, the data is converted to or from 8-bit binary representa- |
| 3893 | tion according to the FORMAT statement associated with the READ or |
| 3894 | WRITE. Standard OS/8 file format packs three 8-bit characters into |
| 3895 | two 12-bit words as follows: |
| 3896 | |
| 3897 | MASS STORAGE CORE |
| 3898 | ----------------------------- ------------------ |
| 3899 | | WORD 3 | | | WORD 1 | |
| 3900 | | bits 0-3 | WORD 1 | |----------------| |
| 3901 | |---------------------------- | WORD 2 | |
| 3902 | | WORD 3 | | |----------------| |
| 3903 | | bits 4-7 | WORD 2 | | WORD 3 | |
| 3904 | ----------------------------- ------------------ |
| 3905 | |
| 3906 | Unformatted (i.e. direct access) READ and WRITE operations also |
| 3907 | operate on standard OS/8 format files, with each statement causing one |
| 3908 | FORTRAN IV record to be read or written. A FORTRAN IV record must |
| 3909 | contain at least one OS/8 block, and always contains an integral |
| 3910 | number of blocks. The number of variables contained in a 1-block |
| 3911 | record depends upon the content and format of the I/O list, as |
| 3912 | follows: |
| 3913 | |
| 3914 | Number of 12-bit Number of |
| 3915 | Format type Words/Variable Variables/Block |
| 3916 | ___________ ________________ _______________ |
| 3917 | |
| 3918 | Integer 3 85 |
| 3919 | Real 3 85 |
| 3920 | Double precision 6 42 1/2 |
| 3921 | Complex 6 42 1/2 |
| 3922 | |
| 3923 | It is possible to mix any types of data in an I/O list; however, no |
| 3924 | more than 85 variables may be stored in one OS/8 block. The number of |
| 3925 | blocks required for a FORTRAN IV record depends, therefore, upon the |
| 3926 | number of variables in the I/O list, and may be minimized by supplying |
| 3927 | every direct access WRITE with sufficient data to nearly fill an |
| 3928 | integral number of blocks without overflowing the last block. |
| 3929 | |
| 3930 | The last word in every file block contains a block count sequence |
| 3931 | number and is not available for data storage. FRTS assigns block |
| 3932 | count numbers sequentially, beginning with 1, whenever a file is |
| 3933 | written. Block count numbers must be maintained by the user when |
| 3934 | FORTRAN IV files are created outside of an OS/8 FORTRAN IV |
| 3935 | environment. While reading a binary file, FRTS checks the block count |
| 3936 | sequence numbers on input blocks and ignores any block whose sequence |
| 3937 | number is larger than expected. Sequence number checking is disabled |
| 3938 | during direct access READ operations. |
| 3939 | |
| 3940 | When FRTS is loaded and started, the initialization routines deter- |
| 3941 | mine what optional hardware, such as FPP-12 Floating Point Processor |
| 3942 | or KE8E Extended Arithmetic Element, is present in the running |
| 3943 | hardware configuration. The initialization routines then modify FRTS |
| 3944 | |
| 3945 | 4-13 |
| 3946 | \f |
| 3947 | |
| 3948 | |
| 3949 | to use the optional hardware, if available. When an FPP is present in |
| 3950 | the system and it becomes desirable to disable the FPP under FRTS, |
| 3951 | this may be accomplished by changing the content of location 12621 |
| 3952 | from 6555 to 7200. The extended arithmetic element may be disabled in |
| 3953 | the same manner by changing the content of FRTS location 12623 from |
| 3954 | 7413 to 7200. These changes must be made before FRTS is started. The |
| 3955 | OS/8 monitor GET and ODT commands provide an excellent mechanism for |
| 3956 | changes of this type. |
| 3957 | |
| 3958 | The FRTS internal line printer handler uses a linked ring buffer for |
| 3959 | maximum I/O buffering efficiency. The buffer consists of several |
| 3960 | contiguous sections of memory, linked together by pointers. All of |
| 3961 | these buffer segments are located above 04000, so that the pointers |
| 3962 | are readily distinguishable from buffered characters. The entire |
| 3963 | 07400 page is included in the line printer ring buffer. If it becomes |
| 3964 | desirable to modify FRTS by patching or reassembly, most of the 07400 |
| 3965 | page may be reclaimed from the buffer by changing the content of |
| 3966 | location 07402 from 7577 to 5164. This frees up locations 07403 to |
| 3967 | 07577 for new code and still leaves about eighty character positions |
| 3968 | in the LPT ring buffer. |
| 3969 | |
| 3970 | Because FRTS executes with the processor interrupt system enabled, it |
| 3971 | may hang up on hardware configurations that include equipment capable |
| 3972 | of generating spurious program interrupts. In addition, any OS/8 I/O |
| 3973 | device handler that exits without clearing all device flags may cause |
| 3974 | troublesome interrupts when it is assigned as a FORTRAN I/O unit under |
| 3975 | FRTS. To counteract these potential problems, FRTS provides certain |
| 3976 | areas that are reserved for inclusion of user-generated code designed |
| 3977 | to clear device flags and/or inhibit spurious interrupts. |
| 3978 | |
| 3979 | A string of NOP instructions beginning at location 04020 is executed |
| 3980 | during FRTS initialization, just before the interrupt system is |
| 3981 | enabled. When the /H option is specified to FRTS, the system halts |
| 3982 | after these NOPs have been executed and the interrupt system has been |
| 3983 | enabled. Another string of NOPs occupying the eight locations from |
| 3984 | 03746 to 03755 is executed after every call to an OS/8 device handler. |
| 3985 | Any of these NOP instructions may be replaced by flag-handling or |
| 3986 | interrupt-servicing code. If additional memory locations are |
| 3987 | required, they may be obtained by replacing some of the code from |
| 3988 | locations 04007 to 04017 with flag-handling code. Locations 04007-17 |
| 3989 | are used to clear flags associated with LAB-8/E peripheral devices. |
| 3990 | |
| 3991 | Due to memory limitations, it is not possible to add internal I/O |
| 3992 | device handlers to the four internal handlers supplied with the |
| 3993 | system. However, FORTRAN I/O unit 0, which is not defined by the ANSI |
| 3994 | standard, may be specified for terminal I/O via the internal console |
| 3995 | terminal handler. I/O unit 0 is not re-assignable. |
| 3996 | |
| 3997 | The FRTS /P option provides a mechanism whereby the core image gener- |
| 3998 | ated from a FORTRAN program may be punched onto paper tape in binary |
| 3999 | loader format. This permits the loader image to be executed on a |
| 4000 | hardware configuration that does not include mass-storage devices. To |
| 4001 | use the /P option, specify /P to FRTS and assign a device or file as |
| 4002 | FORTRAN I/O unit 9. Assigning the paper tape punch as unit 9 causes |
| 4003 | |
| 4004 | 4-14 |
| 4005 | \f |
| 4006 | |
| 4007 | |
| 4008 | /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 6 |
| 4009 | |
| 4010 | /INTERRUPT DRIVEN I/O HANDLERS |
| 4011 | |
| 4012 | 00236 0000 LPT, 0 /RING-BUFFERED - LP08 OR LS8E |
| 4013 | 00237 0176 AND [377 /JUST IN CASE |
| 4014 | 00240 7450 LPTSNA, SNA |
| 4015 | 00241 5765 JMP I (IOERR /CANNOT BE USED FOR INPUT |
| 4016 | 00242 6002 IOF |
| 4017 | 00243 3667 DCA I LPPUT |
| 4018 | 00244 1003 TAD LPGET |
| 4019 | 00245 7041 CIA |
| 4020 | 00246 1267 TAD LPPUT |
| 4021 | 00247 7640 SZA CLA /IS LPT QUIET? |
| 4022 | 00250 5253 JMP .+3 /NO |
| 4023 | 00251 1667 TAD I LPPUT |
| 4024 | 00252 6666 LLS /YES - START 'ER UP |
| 4025 | 00253 7201 CLA IAC |
| 4026 | 00254 6665 LIE /ENABLE LPT INTERRUPTS |
| 4027 | 00255 1267 TAD LPPUT /1 IN AC, REMEMBER? |
| 4028 | 00256 3267 DCA LPPUT |
| 4029 | 00257 1667 TAD I LPPUT |
| 4030 | 00260 7510 SPA |
| 4031 | 00261 5256 JMP .-3 /NEGATIVE NUMBERS ARE BUFFER LINKS |
| 4032 | 00262 7640 SZA CLA /ANY ROOM LEFT IN BUFFER? |
| 4033 | 00263 4764 JMS I (HANG |
| 4034 | 00264 0436 LPUHNG /WAIT FOR LINE PRINTER |
| 4035 | 00265 6001 ION /TURN INTERRUPTS BACK ON |
| 4036 | 00266 5636 JMP I LPT /RETURN |
| 4037 | |
| 4038 | 00267 5165 LPPUT, LPBUFR |
| 4039 | |
| 4040 | 00270 0000 PTP, 0 /PAPER TAPE PUNCH HANDLER |
| 4041 | 00271 7450 SNA |
| 4042 | 00272 5765 JMP I (IOERR /INPUT IS ERROR |
| 4043 | 00273 3236 DCA LPT /SAVE CHAR |
| 4044 | 00274 6002 IOF |
| 4045 | 00275 1006 TAD POCHR /IF PUNCH IS NOT IDLE, |
| 4046 | 00276 7640 SZA CLA /WE DISMISS JOB |
| 4047 | 00277 4764 JMS I (HANG |
| 4048 | 00300 0502 PPUHNG /WAIT FOR PUNCH INTERRUPT |
| 4049 | 00301 1236 TAD LPT |
| 4050 | 00302 6026 PLS /OUTPUT CHAR |
| 4051 | 00303 3006 DCA POCHR /SET FLAG NON-ZERO |
| 4052 | 00304 6001 ION |
| 4053 | 00305 5670 JMP I PTP |
| 4054 | |
| 4055 | /*K* THE FOLLOWING ADDRESSES GET FALLEN INTO & MUST BE SMALL |
| 4056 | |
| 4057 | IFNZRO PPUHNG&7000 <--ERROR--> |
| 4058 | IFNZRO TTUHNG&7000 <--ERROR--> |
| 4059 | IFNZRO KBUHNG&7000 <--ERROR--> |
| 4060 | IFNZRO RDUHNG&7000 <--ERROR--> |
| 4061 | IFNZRO LPUHNG&7000 <--ERROR--> |
| 4062 | |
| 4063 | 4-15 |
| 4064 | \f |
| 4065 | |
| 4066 | |
| 4067 | /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 7 |
| 4068 | |
| 4069 | /INTERRUPT-DRIVEN PTR AND TELETYPE HANDLER |
| 4070 | |
| 4071 | 00306 0000 PTR, 0 /CRUDE READER HANDLER |
| 4072 | 00307 7640 SZA CLA |
| 4073 | 00310 5765 JMP I (IOERR /OUTPUT ILLEGAL TO PTR |
| 4074 | 00311 6002 IOF |
| 4075 | 00312 6014 RFC /START READER |
| 4076 | 00313 4764 JMS I (HANG |
| 4077 | 00314 0510 RDUHNG /HANG UNTIL COMPLETE |
| 4078 | 00315 1007 TAD RDRCHR /GET CHARACTER |
| 4079 | 00316 6001 ION |
| 4080 | 00317 5706 JMP I PTR /RETURN |
| 4081 | 00320 0000 TTY, 0 /BUFFERS 2 CHARS ON OUTPUT, 1 ON |
| 4082 | 00321 6002 IOF /DELICATE CODE AHEAD |
| 4083 | 00322 7450 SNA /INPUT OR OUTPUT? |
| 4084 | 00323 5342 JMP KBD /INPUT |
| 4085 | 00324 3236 DCA LPT /OUTPUT - SAVE CHAR |
| 4086 | 00325 1004 TAD TOCHR /GET TTY STATUS |
| 4087 | 00326 7740 SMA SZA CLA /G.T. 0 MEANS A CHAR IS BACKED UP |
| 4088 | 00327 4764 JMS I (HANG |
| 4089 | 00330 0451 TTUHNG /WAIT FOR LOG JAM TO CLEAR |
| 4090 | 00331 1004 TAD TOCHR /NO CHAR BACKED UP - SEE IF TTY |
| 4091 | 00332 7104 CLL RAL /"BUSY" FLAG IN LINK - INTERRUPTS |
| 4092 | 00333 7230 CLA CML RAR /COMPLEMENT OF BUSY IN SIGN |
| 4093 | 00334 1236 TAD LPT /GET CHAR |
| 4094 | 00335 7510 SPA /IF TTY NOT BUSY, |
| 4095 | 00336 6046 TLS /OUTPUT CHAR |
| 4096 | 00337 3004 DCA TOCHR /STORE POS OR NEG, BACKED UP |
| 4097 | 00340 6001 TTYRET, ION /TURN INTERRUPTS BACK ON |
| 4098 | 00341 5720 JMP I TTY /AND LEAVE |
| 4099 | |
| 4100 | |
| 4101 | /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 8 |
| 4102 | |
| 4103 | 00342 1005 KBD, TAD KBDCHR /HAS A CHARACTER BEEN INPUT? |
| 4104 | 00343 7650 SNA CLA |
| 4105 | 00344 4764 JMS I (HANG |
| 4106 | 00345 0465 KBUHNG /NO - RUN BACKGROUND UNTIL ONE IS |
| 4107 | 00346 1005 TAD KBDCHR /GET CHARACTER |
| 4108 | 00347 3236 DCA LPT |
| 4109 | 00350 3005 DCA KBDCHR /CHEAR CHARACTER BUFFER |
| 4110 | 00351 1236 TAD LPT |
| 4111 | 00352 5340 JMP TTYRET /RETURN WITH INTERRUPTS ON |
| 4112 | |
| 4113 | 00353 6554 KILFPP, FPHLT /BRING FPP TO A SCREECHING HALT |
| 4114 | 00354 2353 ISZ .-1 |
| 4115 | 00355 5354 JMP .-1 /WAIT FOR IT TO STOP |
| 4116 | 00356 6552 FPICL /CLEAN UP MESS HALT HAS MADE IN FPP |
| 4117 | 00357 7430 SZL /^C OR ^B? |
| 4118 | 00360 5763 JMP I (7600 /^C - HIYO SILVER, AWAY! |
| 4119 | 00361 6032 KCC /CLEAR KBD FLAG ON ^B |
| 4120 | 00362 4434 CTLBER, JMS I ERR /*** THIS MAY BE DANGEROUS! ** |
| 4121 | |
| 4122 | 4-16 |
| 4123 | \f |
| 4124 | |
| 4125 | |
| 4126 | /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 9 |
| 4127 | |
| 4128 | /INTERRUPT SERVICE ROUTINES |
| 4129 | |
| 4130 | 00400 3322 INTRPT, DCA INTAC |
| 4131 | 00401 7010 RAR |
| 4132 | 00402 3323 DCA INTLNK |
| 4133 | 00403 5207 VINT, JMP .+4 /** MUST BE AT 403 ** |
| 4134 | IFNZRO VINT-403 <--- CHANGE LOADER!!!> |
| 4135 | 00404 0000 0 |
| 4136 | 00405 6203 CDF CIF 0 /USER INTERRUPT ROUTINE GOES HERE |
| 4137 | 00406 4604 JMS I .-2 |
| 4138 | |
| 4139 | 00407 6551 FPINT /CHECK FOR FPP DONE |
| 4140 | 00410 5215 JMP LPTEST |
| 4141 | 00411 5314 FPUHNG, JMP DISMIS /ALWAYS GOES TO RESTRT |
| 4142 | |
| 4143 | 00412 5314 VDISMS, JMP DISMIS /FOR USE BY USERS |
| 4144 | 00413 5314 JMP DISMIS |
| 4145 | 00414 5314 JMP DISMIS |
| 4146 | 00415 6661 LPTEST, LSF |
| 4147 | 00416 5240 JMP NOTLPT |
| 4148 | 00417 6662 LPTLCF, LCF /CLEAR FLAG |
| 4149 | 00420 1403 TAD I LPGET |
| 4150 | 00421 7650 SNA CLA /CHECK FOR SPURIOUS INTERRUPT |
| 4151 | 00422 5314 JMPDIS, JMP DISMIS /GO AWAY IF SO |
| 4152 | 00423 3403 DCA I LPGET /ZERO CHAR JUST OUTPUT |
| 4153 | 00424 2003 ISZ LPGET |
| 4154 | 00425 1403 TAD I LPGET |
| 4155 | 00426 7510 SPA |
| 4156 | 00427 3003 DCA LPGET /TAKE CARE OF BUFFER LINKS |
| 4157 | 00430 7450 SNA |
| 4158 | 00431 1403 TAD I LPGET /HAKE SURE CHAR IS IN AC |
| 4159 | 00432 7440 SZA /IS THERE A CHARACTER? |
| 4160 | 00433 6666 LLS /YES - PRINT IT |
| 4161 | 00434 7200 CLA |
| 4162 | 00435 6661 LSF /CHECK FOR IMMEDIATE FLAG |
| 4163 | 00436 5314 LPUHNG, JMP DISMIS /NO - MAYBE RESTART PROGRAM |
| 4164 | 00437 5217 JMP LPTLCF /YES - LOOP |
| 4165 | |
| 4166 | 00440 6041 NOTLPT, TSF /CHECK TTY |
| 4167 | 00441 5252 JMP NOTTTY |
| 4168 | 00442 6042 TCF /CLEAR FLAG |
| 4169 | 00443 1004 TAD TOCHR /GET TTY STATUS |
| 4170 | 00444 7540 SMA SZA /IF THERE IS A CHARACTER WAITING, |
| 4171 | 00445 6046 TLS /OUTPUT IT. |
| 4172 | 00446 7740 SMA SZA CLA /CHANGE "WAITING" TO "BUSY", |
| 4173 | 00447 7130 STL RAR /"BUSY" TO "IDLE". |
| 4174 | 00450 3004 DCA TOCHR |
| 4175 | 00451 5314 TTUHNG, JMP DISMIS |
| 4176 | |
| 4177 | |
| 4178 | |
| 4179 | |
| 4180 | |
| 4181 | 4-17 |
| 4182 | \f |
| 4183 | |
| 4184 | |
| 4185 | /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 10 |
| 4186 | |
| 4187 | /KBD AND PTP INTERRUPTS |
| 4188 | |
| 4189 | 00452 6031 NOTTTY, KSF |
| 4190 | 00453 5276 JMP NOTKBD |
| 4191 | 00454 1175 TAD [200 |
| 4192 | 00455 6034 KRS /USE KRS TO FORCE PARITY BIT |
| 4193 | 00456 3005 DCA KBDCHR /AND ALSO SO THAT ^C WILL STILL |
| 4194 | 00457 1005 TAD KBDCHR |
| 4195 | 03460 1377 TAD (-202 /CHECK FOR ^C OR ^B |
| 4196 | 00461 7110 CLL RAR |
| 4197 | 00462 7650 SNA CLA |
| 4198 | 00463 5266 JMP CTCCTB /YUP - TAKE SOME DRASTIC ACTION |
| 4199 | 00464 6032 KCC /DATA CHARACTER - CLEAR FLAG |
| 4200 | 00465 5314 KBUHNG, JMP DISMIS |
| 4201 | |
| 4202 | 00466 1073 CTCCTB, TAD CTCINH |
| 4203 | 00467 7650 SNA CLA /ARE WE IN A HANDLER? |
| 4204 | 00470 5366 JMP NOTINH /NO |
| 4205 | 00471 1323 TAD INTLNK |
| 4206 | 00472 7104 CLL RAL /YES - RETURN WITH INTERRUPTS OFF |
| 4207 | 00473 1322 TAD INTAC /TRUST IN GOD AND RTS |
| 4208 | 00474 6244 RMF |
| 4209 | 00475 5400 JMP I 0 |
| 4210 | |
| 4211 | 00476 6021 NOTKBD, PSF |
| 4212 | 00477 5303 JMP NOTPTP |
| 4213 | 00500 6022 PCF /P.T. PUNCH INTERRUPT - CLEAR FLAG |
| 4214 | 00501 3006 DCA POCHR /CLEAR SOFTWARE FLAG |
| 4215 | 00502 5314 PPUHNG, JMP DISMIS |
| 4216 | |
| 4217 | 00503 6011 NOTPTP, RSF |
| 4218 | 00504 5311 JMP LPTERR |
| 4219 | 00505 1175 TAD [200 |
| 4220 | 00506 6012 RRB /GET RDR CHAR |
| 4221 | 00507 3007 DCA RDRCHR |
| 4222 | 00510 5314 RDUHNG, JMP DISMIS |
| 4223 | |
| 4224 | 00511 6663 LPTERR, LSE /TEST FOR LP08 ERROR FLAG |
| 4225 | 00512 7410 SKP |
| 4226 | 00513 6667 LIF /DISABLE LP08 INTERRUPTS IF ERROR |
| 4227 | 00514 1323 DISMIS, TAD INTLNK |
| 4228 | 00515 7104 CLL RAL |
| 4229 | 00516 1322 TAD INTAC /RESTORE AC AND LINK |
| 4230 | 00517 6244 RMF |
| 4231 | 00520 6001 ION |
| 4232 | 00521 5400 JMP I 0 /RETURN FROM THE INTERRUPT |
| 4233 | |
| 4234 | 00522 0000 INTAC, 0 |
| 4235 | 00523 0000 INTLNK, 0 |
| 4236 | |
| 4237 | |
| 4238 | |
| 4239 | |
| 4240 | 4-18 |
| 4241 | \f |
| 4242 | |
| 4243 | |
| 4244 | /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 11 |
| 4245 | |
| 4246 | /BACKGROUND INITIATE/TERMINATE ROUTINE |
| 4247 | |
| 4248 | 00524 0000 HANG, 0 /ALWAYS CALLED WITH INTERRUPTS OFF! |
| 4249 | 00525 1724 TAD I HANG /GET POINTER TO UNHANGING LOCATION |
| 4250 | 00526 3371 DCA UNHANG |
| 4251 | 00527 6214 RDF /GET FIELD CALLED FROM |
| 4252 | 00530 1332 TAD HCIDF0 |
| 4253 | 00531 3364 DCA HNGCDF /SAVE FOR RETURN |
| 4254 | 00532 6203 HCIDF0, CDF CIF 0 |
| 4255 | 00533 1376 TAD (JMP RESTRT /CHANGE THE "JMP DISMIS" |
| 4256 | 00534 3771 DCA I UNHANG /TO A "JMP RESTRT" |
| 4257 | 00535 1373 TAD BACKLK |
| 4258 | 00536 7104 CLL RAL |
| 4259 | 00537 1372 TAD BACKAC /SET UP BACKGROUND AC AND LINK |
| 4260 | 00540 6202 BAKCIF, CIF 0 |
| 4261 | 00541 6201 BAKCDF, CDF 0 |
| 4262 | 00542 6001 ION |
| 4263 | 00543 5774 JMP I BACKPC /INITIATE BACKGROUND |
| 4264 | |
| 4265 | / COME HERE WHEN THE HANG CONDITION HAS GONE AWAY |
| 4266 | |
| 4267 | 00544 1222 RESTRT, TAD JMPDIS /RESTORE THE UNHANG LOCATION |
| 4268 | 00545 3771 DCA I UNHANG |
| 4269 | 00546 1322 TAD INTAC /SUSPEND THE BACKGROUND |
| 4270 | 00547 3372 DCA BACKAC |
| 4271 | 00550 1323 TAD INTLNK |
| 4272 | 00551 3373 DCA BACKLK |
| 4273 | 00552 1000 TAD 0 |
| 4274 | 00553 3374 DCA BACKPC |
| 4275 | 00554 6234 RIB |
| 4276 | 00555 0174 AND [70 |
| 4277 | 00556 1332 TAD HCIDF0 |
| 4278 | 00557 3340 DCA BAKCIF |
| 4279 | 00560 6234 RIB |
| 4280 | 00561 4436 JMS I MCDF /*K* OK SINCE BACKGROUND DOESN'T |
| 4281 | 00562 3341 DCA BAKCDF |
| 4282 | 00563 2324 ISZ HANG |
| 4283 | 00564 7402 HNGCDF, HLT |
| 4284 | 00565 5724 JMP I HANG /INTERRUPTS ARE OFF - RETURN |
| 4285 | 00566 1222 NOTINH, TAD JMPDIS /IN CASE WE WERE HUNG, WE DON'T |
| 4286 | 00567 3771 DCA I UNHANG /TO GET "UNHUNG" OUT OF THE ERROR |
| 4287 | 00570 5775 JMP I (KILFPP /KILL FPP AND GO TO EXIT OR ERROR |
| 4288 | |
| 4289 | 00571 0000 UNHANG, 0 |
| 4290 | 00572 0000 BACKAC, 0 |
| 4291 | 00573 0000 BACKLK, 0 |
| 4292 | 00574 0227 BACKPC, VBACKG |
| 4293 | 0524 VHANG= HANG |
| 4294 | IFNZRO VHANG-0524 <--CHANGE LOADER!> |
| 4295 | 00575 0353 |
| 4296 | 00576 5344 |
| 4297 | 00577 7576 |
| 4298 | 0600 PAGE |
| 4299 | 4-19 |
| 4300 | \f |
| 4301 | |
| 4302 | |
| 4303 | the image to be punched out directly; however, it may be desirable to |
| 4304 | direct the binary output to an intermediate file for later transfer to |
| 4305 | paper tape via OS/8 PIP. In any event, FRTS returns to the monitor |
| 4306 | once the core image has been transferred. |
| 4307 | |
| 4308 | The output file is a binary image of memory locations 00000 to 07577 |
| 4309 | and 10000 up to the highest location used by the FORTRAN load. The |
| 4310 | content of each field is punched separately with its own checksum and |
| 4311 | leader/trailer. |
| 4312 | |
| 4313 | With the BIN loader resident in field 0, load the binary tape produced |
| 4314 | under the /P option by reading each segment separately and verifying |
| 4315 | the checksum as each memory field is loaded. When all segments have |
| 4316 | been read into memory, start execution at location 00200. The |
| 4317 | following restrictions apply: |
| 4318 | |
| 4319 | 1. OS/8 device handlers which have been assigned FORTRAN I/O |
| 4320 | unit numbers are not necessarily punched out. For this |
| 4321 | reason, I/O unit assignments other than in the form /n=m |
| 4322 | should be avoided. |
| 4323 | |
| 4324 | 2. With respect to the presence of an FPP and/or EAE, the con- |
| 4325 | figuration on which the image is punched must be identical to |
| 4326 | the configuration on which it is to be run. If the punching |
| 4327 | configuration contains hardware that is absent from the |
| 4328 | target configuration, this hardware must be disabled under |
| 4329 | FRTS. If the target configuration contains hardware that is |
| 4330 | absent from the punching configuration, the extraneous |
| 4331 | hardware will not be used. |
| 4332 | |
| 4333 | 3. The statements STOP and CALL EXIT cause a core load produced |
| 4334 | under the /P option to halt. Any fatal error flagged during |
| 4335 | punching or execution causes error traceback followed by a |
| 4336 | halt. Do not press CONTinue in response to either of these |
| 4337 | machine halts. |
| 4338 | |
| 4339 | A FORTRAN IV program is terminated in one of three ways: |
| 4340 | |
| 4341 | 1. A fatal error condition is flagged (CTRL/B) is processed as a |
| 4342 | fatal error. |
| 4343 | |
| 4344 | 2. CTRL/C is recognized, or the CPU is halted and re-started in |
| 4345 | 07600. |
| 4346 | |
| 4347 | 3. A STOP, CALL EXIT, or (under RALF) JSR #EXIT statement is |
| 4348 | executed. |
| 4349 | |
| 4350 | The sequence of events that results in program termination proceeds as |
| 4351 | follows: |
| 4352 | |
| 4353 | |
| 4354 | |
| 4355 | |
| 4356 | |
| 4357 | |
| 4358 | 4-20 |
| 4359 | \f |
| 4360 | |
| 4361 | |
| 4362 | Fatal Error STOP |
| 4363 | (1) (CTRL/B) (2) CTRL/C CALL EXIT (3) |
| 4364 | | | JSR #EXIT | |
| 4365 | ------------- --------------- --------------- |
| 4366 | | BRANCH TO | | | | SIMULATE | |
| 4367 | | ERROR | | EXECUTE IOF | | END FILE ON | |
| 4368 | | ROUTINE | | | | ANY OPEN | |
| 4369 | ------------- --------------- | FILES | |
| 4370 | | | --------------- |
| 4371 | | | |<------- |
| 4372 | ------------- --------------- / \ | |
| 4373 | | | | LET I/O DE- | / TTY, \ | |
| 4374 | | PRINT | | VICE HANDLER| /LPT BUFFERS\_| |
| 4375 | | TRACEBACK | | PROCESS ^C | \ CLEAR / NO |
| 4376 | ------------- --------------- \ ? / |
| 4377 | | | \ / |
| 4378 | | | | YES |
| 4379 | | | | |
| 4380 | | ------------- | --------------- |
| 4381 | | | | | | SET NORMAL | |
| 4382 | ----->| JMP 07605 |<------ | TERMINATION | |
| 4383 | | | | FLAG | |
| 4384 | ------------- --------------- |
| 4385 | | | |
| 4386 | | Location 07605 traps back to FRTS | |
| 4387 | -------------------------------------| |
| 4388 | (A) |
| 4389 | |
| 4390 | |
| 4391 | |
| 4392 | At point A, FRTS executes the following operations. |
| 4393 | |
| 4394 | 1. Read termination routine into memory. |
| 4395 | |
| 4396 | 2. Read OS/8 field 0 resident from block 37 of SYS. |
| 4397 | |
| 4398 | 3. Jump into termination routine at location 17400. |
| 4399 | |
| 4400 | 4. restore normal content of locations 07600 and 07605 (in OS/8 |
| 4401 | resident). |
| 4402 | |
| 4403 | 5. If configuration is an in-core TD8E DECtape system, restore |
| 4404 | second part of TD8E handler from n7600 to 27600. |
| 4405 | |
| 4406 | 6. Wait for TTY to finish all pending I/O. If BATCH is running, |
| 4407 | print LF on TTY and LPT. |
| 4408 | |
| 4409 | 7. If normal termination flag is set, close any output files |
| 4410 | that were opened by the FRTS loader. |
| 4411 | |
| 4412 | 8. Return to OS/8 monitor via location 07605. |
| 4413 | |
| 4414 | |
| 4415 | |
| 4416 | |
| 4417 | 4-21 |
| 4418 | \f |
| 4419 | |
| 4420 | |
| 4421 | /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 78 |
| 4422 | |
| 4423 | 6600 FPPKG= . /FOR EAE OVERLAY |
| 4424 | |
| 4425 | /23-BIT FLOATING PT INTERPRETER |
| 4426 | /W.J. CLOGHER, MODIFIED BY R.LARY FOR FORTRAN |
| 4427 | |
| 4428 | 06600 0000 LPBUF2, ZBLOCK 16 |
| 4429 | 06616 7160 LPBUF3 |
| 4430 | |
| 4431 | 06617 0000 AL1BMP, 0 /*K* UTILITY SUBROUTINE |
| 4432 | 06620 7240 STA |
| 4433 | 06621 1044 TAD ACX |
| 4434 | 06622 3044 DCA ACX |
| 4435 | 06623 4542 JMS I [AL1 |
| 4436 | 06624 5617 JMP I AL1BMP |
| 4437 | |
| 4438 | /FLOATING MULTIPLY-DOES 2 24X12 BIT MULTIPLIES |
| 4439 | 06625 4777 DDMPY, JMS I (DARGET |
| 4440 | 06626 7410 SKP |
| 4441 | 06627 4776 FFMPY, JMS I (ARGET /GET OPERAND |
| 4442 | 06630 4304 JMS MDSET /SET UP FOR MPY-OPX IN AC ON RETN. |
| 4443 | 06631 1044 TAD ACX /DO EXPONENT ADDITION |
| 4444 | 06632 3044 DCA ACX /STORE FINAL EXPONENT |
| 4445 | 06633 3304 DCA MDSET /ZERO TEM STORAGE FOR MPY ROUTINE |
| 4446 | 06634 3054 DCA AC2 |
| 4447 | 06635 1045 TAD ACH /IS FAC=0? |
| 4448 | 06636 7650 SNA CLA |
| 4449 | 06637 3044 DCA ACX /YES-ZERO EXPONENT |
| 4450 | 06640 4334 JMS MP24 /NO-MULTIPLY FAC BY LOW ORDER OPR. |
| 4451 | 06641 1056 TAD OPH /NOW MULTIPLY FAC BY HI ORDER MULT |
| 4452 | 06642 3057 DCA OPL |
| 4453 | 06643 4334 JMS MP24 |
| 4454 | 06644 1054 TAD AC2 /STORE RESULT BACK IN FAC |
| 4455 | 06645 3046 DCA ACL /LOW ORDER |
| 4456 | 06646 1304 TAD MDSET /HIGH ORDER |
| 4457 | 06647 3045 DCA ACH |
| 4458 | 06650 1045 TAD ACH /DO WE NEED TO NORMALIZE? |
| 4459 | 06651 7004 RAL |
| 4460 | 06652 7710 SPA CLA |
| 4461 | 06653 4217 JMS AL1BMP /YES-DO IT FAST |
| 4462 | 06654 1053 TAD AC1 |
| 4463 | 06655 7710 SPA CLA /CHECK OVERFLOW WORD |
| 4464 | 06656 2046 ISZ ACL /HIGH BIT ON - ROUND RESULT |
| 4465 | 06657 5265 JMP MDONE |
| 4466 | 06660 2045 ISZ ACH /LOW ORDER OVERFLOWED - INCREMENT |
| 4467 | 06661 1045 TAD ACH |
| 4468 | 06662 7510 SPA /CHECK FOR OVERFLOW TO 4000 0000 |
| 4469 | 06663 5775 JMP I (SHR1 /WE HANDLE A SIMILIAR CASE IN |
| 4470 | 06664 7200 CLA |
| 4471 | |
| 4472 | |
| 4473 | |
| 4474 | |
| 4475 | |
| 4476 | 4-22 |
| 4477 | \f |
| 4478 | |
| 4479 | |
| 4480 | /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 79 |
| 4481 | |
| 4482 | 06665 3053 MDONE, DCA AC1 /ZERO OVERFLOW WD(DO I NEED THIS??? |
| 4483 | 06666 2333 ISZ MSIGN /SHOULD RESULT BE NEGATIVE? |
| 4484 | 06667 7410 SKP /NO |
| 4485 | 06670 4543 JMS I [FFNEG /YES-NEGATE IT |
| 4486 | 06671 1045 TAD ACH |
| 4487 | 06672 7650 SNA CLA /A ZERO AC MEANS A ZERO EXPONENT |
| 4488 | 06673 3044 DCA ACX |
| 4489 | 06674 1021 TAD DFLG |
| 4490 | 06675 7740 SMA SZA CLA /D.P. INTEGER MODE? |
| 4491 | 06676 1044 TAD ACX /WITH ACX LESS THAN 0? |
| 4492 | 06677 7450 SNA |
| 4493 | 06700 5476 JMP I FPNXT /NO - RETURN |
| 4494 | 06701 7040 CMA |
| 4495 | 06702 4541 JMS I [ACSR /UN-NORMALIZE RESULT |
| 4496 | 06703 5476 JMP I FPNXT /RETURN |
| 4497 | |
| 4498 | |
| 4499 | |
| 4500 | |
| 4501 | /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 80 |
| 4502 | |
| 4503 | /MDSET-SETS UP SIGNS FOR MULTIPLY AND DIVIDE |
| 4504 | /ALSO SHIFTS OPERAND ONE BIT TO THE LEFT. |
| 4505 | /EXIT WITH EXPONENT OF OPERAND IN AC FOR EXPONENT |
| 4506 | /CALCULATION-CALLED WITH ADDRESS OF OPERAND IN AC AND |
| 4507 | /DATA FIELD SET PROPERLY FOR OPERAND. |
| 4508 | |
| 4509 | 06704 0000 MDSET, 0 |
| 4510 | 06705 7344 CLA CLL CMA RAL /SET SIGN CHECK TO -2 |
| 4511 | 06706 3333 DCA MSIGN |
| 4512 | 06707 1056 TAD OPH /IS OPERAND NEGATIVE? |
| 4513 | 06710 7700 SMA CLA |
| 4514 | 06711 5314 JMP .+3 /NO |
| 4515 | 06712 4774 JMS I (OPNEG /YES-NEGATE IT |
| 4516 | 06713 2333 ISZ MSIGN /BUMP SIGN CHECK |
| 4517 | 06714 1057 TAD OPL /AND SHIFT OPERAND LEFT ONE BIT |
| 4518 | 06715 7104 CLL RAL |
| 4519 | 06716 3057 DCA OPL |
| 4520 | 06717 1056 TAD OPH |
| 4521 | 06720 7004 RAL |
| 4522 | 06721 3056 DCA OPH |
| 4523 | 06722 3053 DCA AC1 /CLR. OVERFLOW WORD OF FAC |
| 4524 | 06723 1045 TAD ACH /IS FAC NEGATIVE |
| 4525 | 06724 7700 SMA CLA |
| 4526 | 06725 5331 JMP LEV /NO-GO ON |
| 4527 | 06726 4543 JMS I [FFNEG /YES-NEGATE IT |
| 4528 | 06727 2333 ISZ MSIGN /BUMP SIGN CHECK |
| 4529 | 06730 7000 NOP /MAY SKIP |
| 4530 | 06731 1055 LEV, TAD OPX /EXIT WITH OPERAND EXPONENT IN AC |
| 4531 | 06732 5704 JMP I MDSET |
| 4532 | 06733 0000 MSIGN, 0 |
| 4533 | |
| 4534 | |
| 4535 | 4-23 |
| 4536 | \f |
| 4537 | |
| 4538 | |
| 4539 | /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 81 |
| 4540 | |
| 4541 | /24 BIT BY 12 BIT MULTIPLY. MULTIPLIER IS IN OPL |
| 4542 | /MULTIPLICAND IS IN ACH AND ACL |
| 4543 | /RESULT LEFT IN MDSET,AC2, AND AC1 |
| 4544 | |
| 4545 | 06734 0000 MP24, 0 |
| 4546 | 06735 1373 TAD (-14 /SET UP 12 BIT COUNTER |
| 4547 | 06736 3055 DCA OPX |
| 4548 | 06737 1057 TAD OPL /IS MULTIPLIER=0? |
| 4549 | 06740 7440 SZA |
| 4550 | 06741 5345 JMP MPLP1 /NO-GO ON |
| 4551 | 06742 3053 DCA AC1 /YES-INSURE RESULT=0 |
| 4552 | 06743 5734 JMP I MP24 /RETURN |
| 4553 | 06744 1057 MPLP, TAD OPL /SHIFT A BIT OUT OF LOW ORDER |
| 4554 | 06745 7010 MPLP1, RAR /OF MULTIPLIER AND INTO LINK |
| 4555 | 06746 3057 DCA OPL |
| 4556 | 06747 7420 SNL /WAS IT A 1? |
| 4557 | 06750 5356 JMP MPLP2 /NO - 0 - JUST SHIFT PARTIAL PROD |
| 4558 | 06751 1054 TAD AC2 /YES-ADD MULTIPLICAND TO PARTIAL |
| 4559 | 06752 1046 TAD ACL /LOW ORDER |
| 4560 | 06753 3054 DCA AC2 |
| 4561 | 06754 7024 CML RAL /*K* NOTE THE "SNL" 5 WORDS BACK! |
| 4562 | 06755 1045 TAD ACH /HI ORDER |
| 4563 | 06756 1304 MPLP2, TAD MDSET |
| 4564 | 06757 7010 RAR /NOW SHIFT PARTIAL PROD. RIGHT 1 |
| 4565 | 06760 3304 DCA MDSET |
| 4566 | 06761 1054 TAD AC2 |
| 4567 | 06762 7010 RAR |
| 4568 | 06763 3054 DCA AC2 |
| 4569 | 06764 1053 TAD AC1 |
| 4570 | 06765 7010 RAR /OVERFLOW TO AC1 |
| 4571 | 06766 3053 DCA AC1 |
| 4572 | 06767 2055 ISZ OPX /DONE ALL 12 MULTIPLIER BITS? |
| 4573 | 06770 5344 JMP MPLP /NO-GO ON |
| 4574 | 06771 5734 JMP I MP24 /YES-RETURN |
| 4575 | 06773 7764 |
| 4576 | 06774 7203 |
| 4577 | 06775 7110 |
| 4578 | 06776 6514 |
| 4579 | 06777 6460 |
| 4580 | 7000 PAGE |
| 4581 | |
| 4582 | |
| 4583 | /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 82 |
| 4584 | |
| 4585 | /DIVIDE-BY-ZERO ROUTINE - MUST BE AT BEGINNING Of PAGE |
| 4586 | |
| 4587 | 07000 2035 DBAD, ISZ FATAL /DIVIDE BY 0 NON-FATAL |
| 4588 | 07001 4434 JMS I ERR /GIVE ERROR MSG |
| 4589 | 07002 1200 TAD DBAD |
| 4590 | 07003 3044 DCA ACX /RETURN A VERY LARGE POSITIVE NUM |
| 4591 | 07004 7332 AC2000 |
| 4592 | 07005 5325 JMP FD |
| 4593 | |
| 4594 | 4-24 |
| 4595 | \f |
| 4596 | |
| 4597 | |
| 4598 | /FLOATING DIVIDE - USES DIVIDE-AND-CORRECT METHOD |
| 4599 | |
| 4600 | 07006 4777 DDDIV, JMS I (DARGET |
| 4601 | 07007 7410 SKP |
| 4602 | 07010 4776 FFDIV, JMS I (ARGET /GET OPERAND |
| 4603 | 07011 4775 JMS I (MDSET /GO SET UP FOR DIVIDE-OPX IN AC |
| 4604 | 07012 7041 CMA IAC /NEGATE EXP. OF OPERAND |
| 4605 | 07013 1044 TAD ACX /ADD EXP OF FAC |
| 4606 | 07014 3044 DCA ACX /STORE AS FINAL EXPONENT |
| 4607 | 07015 1056 TAD OPH /NEGATE HI ORDER OP. FOR USE |
| 4608 | 07016 7141 CLL CMA IAC /AS DIVISOR |
| 4609 | 07017 3056 DCA OPH |
| 4610 | 07020 4231 JMS DV24 /CALL DIV.--(ACH+ACL)/OPH |
| 4611 | 07021 1046 TAD ACL /SAVE QUOT. FOR LATER |
| 4612 | 07022 3053 DCA AC1 |
| 4613 | 07023 1057 TAD OPL |
| 4614 | 07024 7650 SNA CLA |
| 4615 | 07025 5327 JMP DVL2 /AVOID MULTIPLYING BY 0 |
| 4616 | 07026 1374 TAD (-15 /SET COUNTER FOR 12 BIT MULTIPLY |
| 4617 | 07027 3231 DCA DV24 /TO MULTIPLY QUOT. OF DIV. BY |
| 4618 | 07030 5267 JMP DVLP1 /LOW ORDER OF OPERAND (OPL) |
| 4619 | |
| 4620 | /DIVIDE ROUTINE - (ACH,ACL)/OPH = ACL REMAINDER REM |
| 4621 | |
| 4622 | 07031 0000 DV24, 0 |
| 4623 | 07032 1045 TAD ACH /CHECK THAI DIVISOR IS .GT. |
| 4624 | 07033 1056 TAD OPH /DIVISOR IN OPH (NEGATIVE) |
| 4625 | 07034 7630 SZL CLA /IS IT? |
| 4626 | 07035 5200 JMP DBAD /NO-DIVIDE OVERFLOW |
| 4627 | 07036 1374 TAD (-15 /YES-SET UP 12 BIT LOOP |
| 4628 | 07037 3054 DCA AC2 |
| 4629 | 07040 5251 JMP DV1 /GO BEGIN DIVIDE |
| 4630 | 07041 1045 DV2, TAD ACH /CONTINUE SHIFT OF FAC LEFT |
| 4631 | 07042 7004 RAL |
| 4632 | 07043 3045 DCA ACH /RESTORE HI ORDER |
| 4633 | 07044 1045 TAD ACH /NOW SUBTRACT DIVISOR FROM HI ORDER |
| 4634 | 07045 1056 TAD OPH /DIVIDEND |
| 4635 | 07046 7430 SZL /GOOD SUBTRACT? |
| 4636 | 07047 3045 DCA ACH /YES-RESTORE HI DIVIDEND |
| 4637 | 07050 7200 CLA /NO-DON'T RESTORE--OPH.GT.ACH |
| 4638 | 07051 1046 DV1, TAD ACL /SHIFT FAC LEFT 1 BIT-ALSO SHIFT |
| 4639 | 07052 7004 RAL /1 BIT OF QUOT. INTO LOW ORD OF ACL |
| 4640 | 07053 3046 DCA ACL |
| 4641 | 07054 2054 ISZ AC2 /DONE 12 BITS OF QUOT? |
| 4642 | 07055 5241 JMP DV2 /NO-GO ON |
| 4643 | 07056 5631 JMP I DV24 /YES-RETN W/AC2=0 |
| 4644 | |
| 4645 | |
| 4646 | |
| 4647 | |
| 4648 | |
| 4649 | |
| 4650 | |
| 4651 | |
| 4652 | |
| 4653 | 4-25 |
| 4654 | \f |
| 4655 | |
| 4656 | |
| 4657 | /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 83 |
| 4658 | |
| 4659 | /DIVIDE ROUTINE CONTINUED |
| 4660 | |
| 4661 | 07057 3057 MP12L, DCA OPL /STORE BACK MULTIPLIET |
| 4662 | 07060 1054 TAD AC2 /GET PRODUCT SO FAR |
| 4663 | 07061 7420 SNL /WAS MULTIPLIER BIT A 1? |
| 4664 | 07062 5265 JMP .+3 /NO-JUST SHIFT THE PARTIAL PRODUCT |
| 4665 | 07063 7100 CLL /YES-CLEAR LINK AND ADD MULTIPLICAND |
| 4666 | 07064 1046 TAD ACL /TO PARTIAL PRODUCT |
| 4667 | 07065 7010 RAR /SHIFT PARTIAL PRODUCT-THIS IS HI |
| 4668 | 07066 3054 DCA AC2 /RESULT-STORE BACK |
| 4669 | 07067 1057 DVLP1, TAD OPL /SHIFT A BIT OUT OF MULTIPLIER |
| 4670 | 07070 7010 RAR /AND A BIT OR RESLT. INTO IT (LO |
| 4671 | 07071 2231 ISZ DV24 /DONE ALL BITS? |
| 4672 | 07072 5257 JMP MP12L /NO-LOOP BACK |
| 4673 | 07073 7141 CLL CIA /YES-LOW ORDER PROD. OF QUOT. X |
| 4674 | 07074 3046 DCA ACL /NEGATE AND STORE |
| 4675 | 07075 7024 CML RAL /PROPAGATE CARRY |
| 4676 | 07076 1054 TAD AC2 /NEGATE HI ORDER PRODUCT |
| 4677 | 07077 7161 STL CIA |
| 4678 | 07100 1045 TAD ACH /COMPARE WITH REMAINDER OF FIRST |
| 4679 | 07101 7430 SZL /WELL? |
| 4680 | 07102 5331 JMP DVOPS /GREATER THAN REM. - ADJUST QUOT OF |
| 4681 | 07103 3045 DCA ACH /OK - DO (REM - (Q*OPL)) / OPH |
| 4682 | 07104 4231 DVL3, JMS DV24 /DIVIDE BY OPH (HI ORDER OPERAND) |
| 4683 | 07105 1053 DVL1, TAD AC1 /GET QUOT. OF FIRST DIV. |
| 4684 | 07106 7500 SMA /IF HI ORDER BIT SET-MUST SHIFT 1 |
| 4685 | 07107 5325 JMP FD /NO-ITS NORMALIZED-DONE |
| 4686 | 07110 7100 SHR1, CLL |
| 4687 | 07111 2046 ISZ ACL /ROUND AND SHIFT RIGHT ONE |
| 4688 | 07112 7410 SKP |
| 4689 | 07113 7001 IAC /DOUBLE PRECISION INCREMENT |
| 4690 | 07114 7010 RAR |
| 4691 | 07115 3045 DCA ACH /STORE IN FAC |
| 4692 | 07116 1046 TAD ACL /SHIFT LOW ORDER RIGHT |
| 4693 | 07117 7010 RAR |
| 4694 | 07120 3046 DCA ACL /STORE BACK |
| 4695 | 07121 2044 ISZ ACX /BUMP EXPONENT |
| 4696 | 07122 7000 NOP |
| 4697 | 07123 1045 TAD ACH |
| 4698 | 07124 5306 JMP DVL1+1 /IF FRACT WAS 77777777 WE MUST |
| 4699 | 07125 3045 FD, DCA ACH /STORE HIGH ORDER RESULT |
| 4700 | 07126 5773 JMP I (MDONE /GO LEAVE DIVIDE |
| 4701 | |
| 4702 | 07127 3046 DVL2, DCA ACL /COME HERE IF LOW-ORDER QUO=0 |
| 4703 | 07130 5304 JMP DVL3 /SAVE SOME TIME |
| 4704 | |
| 4705 | |
| 4706 | |
| 4707 | |
| 4708 | |
| 4709 | |
| 4710 | |
| 4711 | |
| 4712 | 4-26 |
| 4713 | \f |
| 4714 | |
| 4715 | |
| 4716 | /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 84 |
| 4717 | |
| 4718 | /ROUTINE TO ADJUST QUOTIENT OF FIRST DIVIDE (MAYBE) WHEN |
| 4719 | /REMAINDER OF THE FIRST DIVIDE IS LESS THAN QUOT*OPL |
| 4720 | |
| 4721 | 07131 7041 DVOPS, CMA IAC /NEGATE AND STORE REVISED REMAINDER |
| 4722 | 07132 3045 DCA ACH |
| 4723 | 07133 7100 CLL |
| 4724 | 07134 1056 TAD OPH |
| 4725 | 07135 1045 TAD ACH /WATCH FOR OVERFLOW |
| 4726 | 07136 7420 SNL |
| 4727 | 07137 5344 JMP DVOP1 /OVERFLOW-DON'T ADJUST QUOT. OF 1 |
| 4728 | 07140 3045 DCA ACH /NO OVERFLOW-STORE NEW REM. |
| 4729 | 07141 7040 CMA /SUBTRACT 1 FROM QUOT OF |
| 4730 | 07142 1053 TAD AC1 /FIRST DIVIDE |
| 4731 | 07143 3053 DCA AC1 |
| 4732 | 07144 7300 DVOP1, CLA CLL |
| 4733 | 07145 1045 TAD ACH /GET HI ORD OF REMAINDER |
| 4734 | 07146 7450 SNA /IS IT ZERO? |
| 4735 | 07147 3046 DVOP2, DCA ACL /YES-MAKE WHOLE THING ZERO |
| 4736 | 07150 3045 DCA ACH |
| 4737 | 07151 4231 JMS DV24 /DIVIDE EXTENDED REM. BY HI DIVISOR |
| 4738 | 07152 1046 TAD ACL /NEGATE THE RESULT |
| 4739 | 07153 7141 CLL CMA IAC |
| 4740 | 07154 3046 DCA ACL |
| 4741 | 07155 7420 SNL /IF QUOT. IS NON-ZERO, SUBTRACT |
| 4742 | 07156 7040 CMA /ONE FROM HIGH ORDER QUOT. |
| 4743 | 07157 5305 JMP DVL1 /GO TO IT |
| 4744 | |
| 4745 | 07160 0000 LPBUF3, ZBLOCK 12 |
| 4746 | 07172 7316 LPBUF4 |
| 4747 | 07173 6665 |
| 4748 | 07174 7763 |
| 4749 | 07175 6704 |
| 4750 | 07176 6514 |
| 4751 | 07177 6460 |
| 4752 | 7200 PAGE |
| 4753 | |
| 4754 | |
| 4755 | |
| 4756 | |
| 4757 | |
| 4758 | |
| 4759 | |
| 4760 | |
| 4761 | |
| 4762 | |
| 4763 | |
| 4764 | |
| 4765 | |
| 4766 | |
| 4767 | |
| 4768 | |
| 4769 | |
| 4770 | |
| 4771 | 4-27 |
| 4772 | \f |
| 4773 | |
| 4774 | |
| 4775 | /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 85 |
| 4776 | |
| 4777 | /"NRMFAC" AND "OPNEG" MUST BE AT 0 AND 3 ON PAGE |
| 4778 | |
| 4779 | 07200 3053 NRMFAC, DCA AC1 /KILL OVERFLOW BIT |
| 4780 | 07201 4271 JMS FFNOR |
| 4781 | 07202 5476 JMP I FPNXT |
| 4782 | |
| 4783 | 07203 0000 OPNEG, 0 /ROUTINE TO NEGATE OPERAND |
| 4784 | 07204 1057 TAD OPL /GET LOW ORDER |
| 4785 | 07205 7141 CLL CMA IAC /NEGATE AND STORE BACK |
| 4786 | 07206 3057 DCA OPL |
| 4787 | 07207 7024 CML RAL /PROPAGATE CARRY |
| 4788 | 07210 1056 TAD OPH /GET HI ORDER |
| 4789 | 07211 7141 CLL CMA IAC /NEGATE AND STORE BACK |
| 4790 | 07212 3056 DCA OPH |
| 4791 | 07213 5603 JMP I OPNEG |
| 4792 | / |
| 4793 | /FLOATING SUBTRACT AND ADD |
| 4794 | / |
| 4795 | 07214 4777 FFSUB, JMS I (ARGET /PICK UP THE OP. |
| 4796 | 07215 4203 JMS OPNEG /NEGATE OPERAND |
| 4797 | 07216 7410 SKP |
| 4798 | 07217 4777 FFADD, JMS I (ARGET /PICK UP OPERAND |
| 4799 | 07220 1056 TAD OPH /IS OPERAND = 0 |
| 4800 | 07221 7650 SNA CLA |
| 4801 | 07222 5476 JMP I FPNXT /YES-DONE |
| 4802 | 07223 1045 TAD ACH /NO-IS FAC=0? |
| 4803 | 07224 7650 SNA CLA |
| 4804 | 07225 5236 JMP DOADD /YES-DO ADD |
| 4805 | 07226 1044 TAD ACX /NO-DO EXPONENT CALCULATION |
| 4806 | 07227 7141 CLL CMA IAC |
| 4807 | 07230 1055 TAD OPX |
| 4808 | 07231 7540 SMA SZA /WHICH EXP. GREATER? |
| 4809 | 07232 5243 JMP FACR /OPERANDS-SHIFT FAC |
| 4810 | 07233 7041 CMA IAC /FAC'S-SHIFT OPERAND=DIFFRNCE+1 |
| 4811 | 07234 4246 JMS OPSR |
| 4812 | 07235 4541 JMS I [ACSR /SHIFT FAC ONE PLACE RIGHT |
| 4813 | 07236 1055 DOADD, TAD OPX /SET EXPONENT OF RESULT |
| 4814 | 07237 3044 DCA ACX |
| 4815 | 07240 4537 JMS I [OADD /DO THE ADDITION |
| 4816 | 07241 4271 JMS FFNOR /NORMALIZE RESULT |
| 4817 | 07242 5476 JMP I FPNXT /RETURN |
| 4818 | 07243 4541 FACR, JMS I [ACSR /SHIFT FAC = DIFF.+1 |
| 4819 | 07244 4246 JMS OPSR /SHIFT OPR. 1 PLACE |
| 4820 | 07245 5236 JMP DOADD /DO ADDITION |
| 4821 | |
| 4822 | |
| 4823 | |
| 4824 | |
| 4825 | |
| 4826 | |
| 4827 | |
| 4828 | |
| 4829 | |
| 4830 | 4-28 |
| 4831 | \f |
| 4832 | |
| 4833 | |
| 4834 | /FORTRAN 4 RUNTIME SYSTEM - R.L PAL8-V8 PAGE 86 |
| 4835 | |
| 4836 | /OPERAND SHIFT RIGHT-ENTER WITH POSITIVE COUNT-1 IN AC |
| 4837 | |
| 4838 | 07246 0000 OPSR, 0 |
| 4839 | 07247 7040 CMA /- (COUNT+1) TO SHIFT COUNTER |
| 4840 | 07250 3052 DCA AC0 |
| 4841 | 07251 1056 LOP2, TAD OPH /GET SIGN BIT |
| 4842 | 07252 7100 CLL /TO LINK |
| 4843 | 07253 7510 SPA |
| 4844 | 07254 7020 CML /WITH HI MANTISSA IN AC |
| 4845 | 07255 7010 RAR /SHIFT IT RIGHT, PROPAGATING SIGN |
| 4846 | 07256 3056 DCA OPH /STORE BACK |
| 4847 | 07257 1057 TAD OPL |
| 4848 | 07260 7010 RAR |
| 4849 | 07261 3057 DCA OPL /STORE LO ORDER BACK |
| 4850 | 07262 2055 ISZ OPX /INCREMENT EXPONENT |
| 4851 | 07263 7000 NOP |
| 4852 | 07264 2052 ISZ AC0 /DONE ALL SHIFTS? |
| 4853 | 07265 5251 JMP LOP2 /NO-LOOP |
| 4854 | 07266 7010 RAR /SAVE 1 BIT OF OVERFLOW |
| 4855 | 07267 3054 DCA AC2 /IN AC2 |
| 4856 | 07270 5646 JMP I OPSR /YES-RETN. |
| 4857 | |
| 4858 | 07271 0000 FFNOR, 0 /ROUTINE TO NORMALIZE THE FAC |
| 4859 | 07272 1045 TAD ACH /GET THE HI ORDER MANTISSA |
| 4860 | 07273 7450 SNA /ZERO? |
| 4861 | 07274 1046 TAD ACL /YES-HOW ABOUT LOW? |
| 4862 | 07275 7450 SNA |
| 4863 | 07276 1053 TAD AC1 /LOW=0, IS OVRFLO BIT ON? |
| 4864 | 07277 7650 SNA CLA |
| 4865 | 07300 5313 JMP ZEXP /#=0-ZERO EXPONENT |
| 4866 | 07301 7332 NORMLP, CLA CLL CML RTR /NOT 0-MAKE A 2000 IN AC |
| 4867 | 07302 1045 TAD ACH /ADD HI ORDER MANTISSA |
| 4868 | 07303 7440 SZA /HI ORDER = 6000 |
| 4869 | 07304 5307 JMP .+3 /NO-CHECK LEFT MOST DIGIT |
| 4870 | 07305 1046 TAD ACL /YES-6000 OK IF LOW=O |
| 4871 | 07306 7640 SZA CLA |
| 4872 | 07307 7710 SPA CLA /2,3,4,5,ARE LEGAL LEFT MOST DIGS. |
| 4873 | 07310 5314 JMP FFNORR /FOR NORMALIZED #-(+2000=4,5,6,7) |
| 4874 | 07311 4534 JMS I (AL1BMP /SHIFT AC LEFT AND BUMP ACX DOWN |
| 4875 | 07312 5301 JMP NORMLP /GO BACK AND SEE IF NORMALIZED |
| 4876 | 07313 3044 ZEXP, DCA ACX |
| 4877 | 07314 3053 FFNORR, DCA AC1 /DONE W/NORMALIZE - CLEAR AC1 |
| 4878 | 07315 5671 JMP I FFNOR /RETURN |
| 4879 | |
| 4880 | 07316 0000 LPBUF4, ZBLOCK 60 |
| 4881 | 07376 7400 LPBUFE |
| 4882 | 07377 6514 |
| 4883 | 7400 PAGE |
| 4884 | |
| 4885 | |
| 4886 | |
| 4887 | |
| 4888 | |
| 4889 | 4-29 |
| 4890 | \f |
| 4891 | |
| 4892 | |
| 4893 | CHAPTER 5 |
| 4894 | |
| 4895 | LIBRA AND FORLIB |
| 4896 | |
| 4897 | |
| 4898 | The binary output of an assembly under RALF is called a RALF module. |
| 4899 | Every RALF module consists of an External Symbol Dictionary (or ESD) |
| 4900 | and associated text. The ESD lists all global symbols defined in the |
| 4901 | assembly, while the text contains the actual binary output along with |
| 4902 | relocation data. |
| 4903 | |
| 4904 | There are three major classes of global symbols. Entry points are |
| 4905 | global symbols defined in a module and referenced by code in other |
| 4906 | modules. Thus, entry points include the names of all modules and the |
| 4907 | names of all globally callable subroutines within modules. Externs are |
| 4908 | global symbols that are referenced in a module but not defined in that |
| 4909 | module. For example, the entry point of module A would appear as an |
| 4910 | extern if referenced in module B. The COMMON area comprises a third |
| 4911 | class of global symbols including all global symbols which define |
| 4912 | COMMON. |
| 4913 | |
| 4914 | A FORTRAN IV library is a specially formatted file, created with |
| 4915 | LIBRA, consisting of a library catalog (which lists section names and |
| 4916 | entry points of library modules) and a set of RALF modules, perhaps |
| 4917 | interspersed with empty subfiles. The loader uses one such library, |
| 4918 | specified by the user, to resolve externs while building a loader |
| 4919 | image file. The general structure of a FORTRAN IV library is: |
| 4920 | |
| 4921 | ---------------------------------------------------------------- |
| 4922 | | CATALOG | MODULE | FREE | MODULE | MODULE | \ |
| 4923 | | | | AREA | | | etc. / |
| 4924 | | | | | | | \ |
| 4925 | ----------------------------------------------------------------- |
| 4926 | |
| 4927 | LIBRA is a very simple program, basically a file-to-file copy inside |
| 4928 | several nested loops. The outer loop begins at START, and calls the |
| 4929 | command decoder for specification of the library and input files. If |
| 4930 | no library is specified, the previous library name is used (initially |
| 4931 | this is SYS:FORLIB.RL). If a new name is given, but no extension is |
| 4932 | specified, .RL is forced. A check is made to verify that the |
| 4933 | specified library is on a file-structured device, and the handler is |
| 4934 | FETCHed. |
| 4935 | |
| 4936 | At ZTEST, the /Z switch is tested. If it was set, control passes to |
| 4937 | NEWLIB to create a new library. Otherwise, an attempt is made to find |
| 4938 | an old library of the specified name on the device. If it fails, |
| 4939 | control passes to NEWLIB. Otherwise, the catalog of the old library |
| 4940 | is read and scanned to determine the starting block of available |
| 4941 | space. This is stored at LAVAIL. Control then passes to GETINF to |
| 4942 | begin reading input files. |
| 4943 | |
| 4944 | If /Z was set, or the specified library isn't found, a new library is |
| 4945 | entered at NEWLIB, and an empty catalog is written. Control passes to |
| 4946 | GETINF. There, a check is made to determine whether input is |
| 4947 | |
| 4948 | 5-1 |
| 4949 | \f |
| 4950 | |
| 4951 | |
| 4952 | presently coming from another library. If it is, control passes to |
| 4953 | INLIB to obtain the next module from the library. Otherwise, the next |
| 4954 | input file is obtained from the command decoder area in field 1, and |
| 4955 | if one exists, control passes to FTCHIN to load the handler. If there |
| 4956 | is none, the /C switch is tested. If it is not set, control is passed |
| 4957 | to LCLOSE to close the library. If it is set, however, the command |
| 4958 | decoder is recalled to obtain a continuation of the preceding input |
| 4959 | line, and control returns to NXTINF to look in the command decoder |
| 4960 | area. |
| 4961 | |
| 4962 | At FTCHIN, the unit, starting block, and length of the next input file |
| 4963 | are obtained from the command decoder area, the appropriate device |
| 4964 | handler is fetched, and at LUKMOD, the input file is read to ensure |
| 4965 | that it is either a module or a library. If a library, control passes |
| 4966 | to GOTLIB, which sets INLSW and goes to INLIB to obtain the first |
| 4967 | module from the library. Otherwise, the length is checked against the |
| 4968 | available length in the library, to ensure that this module can be fit |
| 4969 | in, and control goes to NXTEBK to read the ESD. |
| 4970 | |
| 4971 | At INLIB, the catalog of the library being input is read, and scanned |
| 4972 | until a module is found with a starting block greater than the |
| 4973 | starting block of the last input module (in the case of the first |
| 4974 | module in a library, MODBLK, which normally contains the starting |
| 4975 | block of a module, contains the starting block of the library, so this |
| 4976 | scan yields the starting block of the first module in the library). |
| 4977 | When the next module has been found, control returns to LUKMOD to |
| 4978 | check the length of the module against the available length in the |
| 4979 | library. |
| 4980 | |
| 4981 | At NXTEBK, the end of the input module is scanned for entry point and |
| 4982 | section names. Whenever one is found, the catalog of the output |
| 4983 | library is scanned for a matching name. If a match is found, control |
| 4984 | passes to GOTMAT, which prints the duplicated name, and if the /I |
| 4985 | switch is set, asks the operator which name to keep. If he types N, |
| 4986 | for new, control passes to DLETO to delete the old name. Otherwise, |
| 4987 | control is passed to ESDLND to find the next entry point or section |
| 4988 | name in the input. If /I is not set, /R is tested. If it is not set, |
| 4989 | control is passed to ESDLND. If it is, control flows into DELTO, |
| 4990 | where the old name is cleared, and the rest of the catalog is scanned |
| 4991 | to find the first available name slot. Control then passes to INSERT. |
| 4992 | |
| 4993 | If no match was found, the /I switch is tested. If it was set, the |
| 4994 | operator is asked whether to include the name. If he types, N, for |
| 4995 | no, control is passed to ESDLND. Otherwise, or if /I was not set, a |
| 4996 | pointer is set up for the new name, and control passes to INSERT, |
| 4997 | where the new name is added to the catalog. |
| 4998 | |
| 4999 | When the entire ESD has been scanned, INCLUD is tested to determine |
| 5000 | whether any name has been included in the catalog, and assuming at |
| 5001 | least one has, the module is copied into the library, and LAVAIL is |
| 5002 | updated to indicate the next available block in the library. Control |
| 5003 | returns to GETINF for another module. |
| 5004 | |
| 5005 | |
| 5006 | |
| 5007 | 5-2 |
| 5008 | \f |
| 5009 | |
| 5010 | |
| 5011 | LCLOSE receives control whenever the end of the input file string is |
| 5012 | reached and /C is not set. Here, any remaining changes in the library |
| 5013 | catalog are written, and if a new library was entered, it is closed. |
| 5014 | Control passes to CATLST, to create a catalog listing. The second |
| 5015 | output file, if any was specified, is opened, a title is output to it, |
| 5016 | and at PRCAT, the entire contents of the catalog are listed. When |
| 5017 | this process is complete, the output file is closed, and control |
| 5018 | returns to start for more command decoder input. |
| 5019 | |
| 5020 | User-coded modules may be added to the system library or incorporated |
| 5021 | in a new library provided that entry points, variable storage |
| 5022 | allocations, calling sequences, error conditions and the like are |
| 5023 | handled with care. |
| 5024 | |
| 5025 | Every library module must have a unique section (and entry) name(s). |
| 5026 | The library supplied by DEC uses the character # before names where |
| 5027 | duplication in the FORTRAN program may be possible. Note that this |
| 5028 | character is acceptable to RALF, but is illegal in a FORTRAN source. |
| 5029 | If more than one entry is required to the routine, they should be |
| 5030 | listed as such using the pseudo-op ENTRY before they are encountered |
| 5031 | as tags in the code. Thus, if a double precision tangent routine is |
| 5032 | being written, it may be helpful to have an entry for a double |
| 5033 | precision co-tangent calculation also. Appropriate code would be: |
| 5034 | |
| 5035 | SECT DTAN |
| 5036 | JA #DTAN |
| 5037 | ENTRY DCOT |
| 5038 | JA #DCOT |
| 5039 | . |
| 5040 | . |
| 5041 | . |
| 5042 | #DCOT, |
| 5043 | . |
| 5044 | . |
| 5045 | . |
| 5046 | #DTAN, |
| 5047 | |
| 5048 | When routines will handle double precision or complex values, allocate |
| 5049 | six words for their storage. Such routines can switch between the |
| 5050 | STARTF (3 word format) and STARTE (6 word format) pseudo-ops as |
| 5051 | required, being careful to define variables of the proper length to |
| 5052 | keep track of temporary locations. |
| 5053 | |
| 5054 | All user-written library routines are called by a JSR in STARTF mode. |
| 5055 | Depending on the type of function, the routine must be coded to exit |
| 5056 | as follows in order to return the result to the program: |
| 5057 | |
| 5058 | Single precision Answer in AC in STARTF mode |
| 5059 | (integer, real and logical) |
| 5060 | |
| 5061 | FLDA ANSWER /In STARTF mode |
| 5062 | JA RETURN /3 word result |
| 5063 | |
| 5064 | |
| 5065 | |
| 5066 | 5-3 |
| 5067 | \f |
| 5068 | |
| 5069 | |
| 5070 | Double precision: Answer in AC in STARTE mode |
| 5071 | |
| 5072 | FLDA ANSWER /In STARTE mode |
| 5073 | JA RETURN /6 word result |
| 5074 | |
| 5075 | Complex: Answer in location #CAC in |
| 5076 | STARTE mode |
| 5077 | |
| 5078 | EXTERN #CAC /Real part in first 3 words |
| 5079 | STARTE /Imaginary in last 3 words |
| 5080 | FLDA ANSWER /Exit in STARTE mode |
| 5081 | FSTA #CAC /6 word result |
| 5082 | JA RETURN |
| 5083 | |
| 5084 | Routines should conform to the FPP FORTRAN calling sequence. An |
| 5085 | example of that sequence follows: |
| 5086 | |
| 5087 | SECT DTAN /Sector name |
| 5088 | JA #DTAN /Jump to Start of Function |
| 5089 | TEXT +DTAN + /6 characters for trace |
| 5090 | /back feature must be |
| 5091 | /immediately before index |
| 5092 | /register assignment. |
| 5093 | DTANXR, SETX XRDTAN /This tag referenced when |
| 5094 | /returning to reset base |
| 5095 | /page and index registers |
| 5096 | SETB BPDTAN /if this routine called. |
| 5097 | |
| 5098 | BPDTAN, F 0.0 /3 words each |
| 5099 | XRDTAN, F 0.0 /These locations may be |
| 5100 | /used for temporary storage or |
| 5101 | ORG 10*3+BPDTAN /If this routine is called, |
| 5102 | /will set up return to it. |
| 5103 | FNOP |
| 5104 | JA DTANXR |
| 5105 | 0 |
| 5106 | DTNRTN, JA . /Return to calling program |
| 5107 | BASE 0 /Still on caller's base page |
| 5108 | #DTAN, STARTD /Start of subroutine |
| 5109 | FLDA 10*3 /Get jump to caller's return jump |
| 5110 | FSTA DTNRTN /Save for return from this routine |
| 5111 | FLDA 0 /Get next location in caller's |
| 5112 | /routine (pointer to argument list) |
| 5113 | SETX XRDTAN /Change index registers to this |
| 5114 | /routine's |
| 5115 | SETB BPDTAN /Change base page to this routine's |
| 5116 | BASE BPDTAN /Change base page to this routine's |
| 5117 | FSTA TEMP /Save pointer |
| 5118 | LDX 1,1 /Set up XRL |
| 5119 | FLDA% TEMP,1 /Get address of argument list |
| 5120 | FSTA TEMP /Save it |
| 5121 | STARTE /A double precision routine |
| 5122 | FLDA% TEMP /Get variable |
| 5123 | FSTA TEMP /Save variable |
| 5124 | |
| 5125 | 5-4 |
| 5126 | \f |
| 5127 | |
| 5128 | |
| 5129 | . |
| 5130 | . |
| 5131 | . /Calculate result |
| 5132 | . |
| 5133 | . |
| 5134 | . |
| 5135 | FLDA ANSWER /Load answer |
| 5136 | JA DTNRTN /Exit |
| 5137 | |
| 5138 | The following conventions must be observed to return to the calling |
| 5139 | program at the correct location, to permit the error trace back |
| 5140 | feature to function properly, and to preserve index registers and base |
| 5141 | page integrity. |
| 5142 | |
| 5143 | Locations 0 and 30 of the called (user-coded) program are determined |
| 5144 | by a statement in the form ORG 10*3+BPAGE which must be followed by a |
| 5145 | two-word jump to the index register and base page assignment |
| 5146 | instructions JA BPXR. In the above example, the code is: |
| 5147 | |
| 5148 | ORG 10*3+BPDATN |
| 5149 | FNOP |
| 5150 | JA DTANXR |
| 5151 | |
| 5152 | By saving the contents of location 30 of the calling program (FLDA |
| 5153 | 10*3,FSTA RETURN) for the return exit, the called program executes |
| 5154 | (when control is returned to it) a JA BPXR to its base page and index |
| 5155 | register assignment statement. In the calling program this resets the |
| 5156 | index registers and base page and then returns to execute the |
| 5157 | instruction in the calling program. In the tangent example above, the |
| 5158 | code is: |
| 5159 | |
| 5160 | FLDA 10*3 |
| 5161 | FSTA DTNRTN |
| 5162 | |
| 5163 | which creates the instruction |
| 5164 | |
| 5165 | JA xxx |
| 5166 | |
| 5167 | at the tag DTNRTN, where xxx is the location in the calling routine |
| 5168 | whose function corresponds to DTANXR in DTAN. |
| 5169 | |
| 5170 | When called, the routine must assign its own base page and index |
| 5171 | registers (SETX XROWN, SETB BPOWN). If arguments are to be passed to |
| 5172 | the called routine, a scheme such as illustrated above permits any |
| 5173 | number of arguments to be passed from the calling program and saved on |
| 5174 | the base page of the called program, in this case just two arguments. |
| 5175 | |
| 5176 | The corresponding code for the calling program (as created by the |
| 5177 | compiler) is: |
| 5178 | |
| 5179 | |
| 5180 | |
| 5181 | |
| 5182 | |
| 5183 | |
| 5184 | 5-5 |
| 5185 | \f |
| 5186 | |
| 5187 | |
| 5188 | EXTERN DTAN |
| 5189 | JSR DTAN |
| 5190 | JA .+4 /Jump past all arguments |
| 5191 | JA A /Argument |
| 5192 | . |
| 5193 | . |
| 5194 | . |
| 5195 | FSTA Q /Save result in some variable |
| 5196 | |
| 5197 | The FORTRAN for such code is: |
| 5198 | |
| 5199 | Q = DTAN (A) |
| 5200 | |
| 5201 | The calling sequence is also discussed in Chapter 2. |
| 5202 | |
| 5203 | To permit the error trace back feature to function properly, a TEXT |
| 5204 | statement followed by a six alphanumeric character name is required |
| 5205 | immediately before the index register and base page assignment |
| 5206 | statements. Thus, if the cotangent routine includes a JSR TAN and an |
| 5207 | unacceptable argument is passed to the tangent function, the trace |
| 5208 | back indicates the location of the problem by a sequence such as: |
| 5209 | |
| 5210 | DIV0 MAIN |
| 5211 | ARGUMENT |
| 5212 | 7777 SIN |
| 5213 | 0000 TAN |
| 5214 | 0000 COT |
| 5215 | 0007 MAIN |
| 5216 | |
| 5217 | (Line numbers are not relevant in RALF modules such as TAN and SIN: |
| 5218 | they are meaningful only in FORTRAN source programs.) |
| 5219 | |
| 5220 | A new library routine may call other new or existing library routines |
| 5221 | as part of its function, as well as the error handling function of the |
| 5222 | run-time system. To invoke the error message program, code such as |
| 5223 | the following is required: |
| 5224 | |
| 5225 | EXTERN #ARGER |
| 5226 | MERROR, TRAP4 #ARGER |
| 5227 | |
| 5228 | Then any condition encountered in the program that is an error should |
| 5229 | jump to MERROR. For example, if an argument of <=0 is illegal, it |
| 5230 | could be examined and handled as follows: |
| 5231 | |
| 5232 | FLDA% ARG2 |
| 5233 | JLE MERROR /<0 error |
| 5234 | FSTA NEXT / Save non-zero value |
| 5235 | |
| 5236 | In this case, the TRAP4 #ARGER at MERROR will produce the message BAD |
| 5237 | ARG DTAN nnnn followed by traceback and program termination. If a new |
| 5238 | library routine would like to use an existing library routine, a JSR |
| 5239 | to that routine is required. The sequence for passing arguments is: |
| 5240 | |
| 5241 | |
| 5242 | |
| 5243 | 5-6 |
| 5244 | \f |
| 5245 | |
| 5246 | |
| 5247 | EXTERN ATAN2 |
| 5248 | JSR ATAN2 |
| 5249 | JA .+6 /Execute upon exit from |
| 5250 | JA A /1st arg |
| 5251 | JA B /2nd arg |
| 5252 | FSTA ANSWER /Save answer |
| 5253 | |
| 5254 | The arguments must be referenced in the order expected by the called |
| 5255 | routine and must agree in number and type. The following routines can |
| 5256 | can be used in this manner: |
| 5257 | |
| 5258 | ROUTINE ARGUMENTS PASSED\r _______ ________________ |
| 5259 | |
| 5260 | AMOD Address of X then Y |
| 5261 | SQRT Address of X |
| 5262 | ALOG10 Address of X |
| 5263 | EXP Address of X |
| 5264 | SIN Address of X |
| 5265 | COS Address of X |
| 5266 | TAN Address of X |
| 5267 | SIND Address of X |
| 5268 | COSD Address of X |
| 5269 | TAND Address of X |
| 5270 | ASIN Address of X |
| 5271 | ACOS Address of X |
| 5272 | ATAN Address of X |
| 5273 | ATAN2 Address of X then Y |
| 5274 | SINH Address of X |
| 5275 | COSH Address of X |
| 5276 | TANH Address of X |
| 5277 | DMOD Address of X then Y |
| 5278 | DSIGN Address of X then Y |
| 5279 | DSIN Address of X |
| 5280 | DLOG Address of X |
| 5281 | DSQRT Address of X |
| 5282 | DCOS Address of X |
| 5283 | DLOG10 Address of X |
| 5284 | DATAN2 Address of X then Y |
| 5285 | DATAN Address of X |
| 5286 | DEXP Address of X |
| 5287 | CMPLX Address of X |
| 5288 | CSIN Address of X |
| 5289 | CCOS Address of X |
| 5290 | REAL Address of X |
| 5291 | AIMAG Address of X |
| 5292 | CONJG Address of X |
| 5293 | CEXP Address of X |
| 5294 | CLOG Address of X |
| 5295 | CABS Address of X |
| 5296 | CSQRT Address of X |
| 5297 | |
| 5298 | For real and double precision routines, the result is returned via the |
| 5299 | FAC (3 or 6 words, respectively). For complex routines, the result is |
| 5300 | returned in #CAC (6 words). |
| 5301 | |
| 5302 | 5-7 |
| 5303 | \f |
| 5304 | |
| 5305 | |
| 5306 | The TAN function from FORLIB is included here as an example of the |
| 5307 | requirements just discussed. The TAN function calls two external |
| 5308 | functions, has the standard calling sequence, and contains an error |
| 5309 | condition exit. |
| 5310 | |
| 5311 | / T A N |
| 5312 | / - - - |
| 5313 | / |
| 5314 | /SUBROUTINE TAN(X) |
| 5315 | SECT TAN /SECTION NAME |
| 5316 | JA #TAN /JUMP AROUND BASE PAGE |
| 5317 | |
| 5318 | EXTERN #ARGER |
| 5319 | TANER, TRAP4 #ARGER /EXIT TO ERROR MESSAGE HANDLER |
| 5320 | TEXT +TAN + /FOR ERROR TRACE BACK |
| 5321 | TANXR, SETX XRTAN /START OF FORMAL CALLING SEQUENCE |
| 5322 | SETB BPTAN |
| 5323 | BTAN, FNOP /START OF BASE PAGE |
| 5324 | 0 |
| 5325 | 0 |
| 5326 | XRTAN, F 0.0 /INDEX REGISTERS |
| 5327 | TAN1, F 0.0 /LOCATIONS 21-42 OCTAL AVAILABLE |
| 5328 | /FOR USER STORAGE |
| 5329 | TAN2, F 0.0 |
| 5330 | ORG 10*3+BPTAN /SET UP FOR A RETURN |
| 5331 | /TO THIS ROUTINE |
| 5332 | FNOP |
| 5333 | JA TANXR /JUMP TO XR + RP ASSIGNMENT |
| 5334 | 0 |
| 5335 | TANRTN, JA . |
| 5336 | BASE 0 |
| 5337 | #TAN, STARTD |
| 5338 | FLDA 10*3 /SAVE RETURN JUMP |
| 5339 | FSTA TANRTN |
| 5340 | FLDA 0 /GET NEXT LOCATION |
| 5341 | /IN CALLING PROGRAM |
| 5342 | SETX XRTAN /SET UP FOR TAN'S INDEX REGS |
| 5343 | SETB BPTAN /SET UP FOR TAN'S BP |
| 5344 | BASE BPTAN |
| 5345 | LDX 1,1 |
| 5346 | FSTA BPTAN |
| 5347 | FLDA% BPTAN,1 /GET ADDRESS OF X |
| 5348 | FSTA BPTAN |
| 5349 | STARTF |
| 5350 | FLDA% BPTAN /GET X |
| 5351 | JEQ TANRTN /IF 0 RETURN NOW |
| 5352 | FSTA TAN1 /SAVE FOR A SECOND |
| 5353 | EXTERN COS |
| 5354 | JSR COS /TAKE COS(X) |
| 5355 | JA .+4 /JUMP AROUND ARGUMENT LIST |
| 5356 | JA TAN1 /REFERENCE TO PASSED ARGUMENT |
| 5357 | JEQ TANER /COS=0. A NO-NO |
| 5358 | FSTA TAN2 /SAVE IT |
| 5359 | EXTERN SIN |
| 5360 | |
| 5361 | 5-8 |
| 5362 | \f |
| 5363 | |
| 5364 | |
| 5365 | JSR SIN /NOW TAKE SIN(X) |
| 5366 | JA .+4 /JUMP AROUND ARGUMENT LIST |
| 5367 | JA TAN1 /REFERENCE TO ARGUMENT |
| 5368 | FDIV TAN2 /DIV BY COS(X) |
| 5369 | JA TANRTN /EXIT |
| 5370 | |
| 5371 | The library routine ONQI illustrates many of the same conventions. |
| 5372 | This listing may also prove valuable as a guide to interfacing with |
| 5373 | the run-time system. |
| 5374 | |
| 5375 | FIELD1 ONQI /ROUTINE TO ADD A |
| 5376 | /HANDLER TO INTERRUPT SKIP CHAIN |
| 5377 | /PUT THIS CODE IN FIELD 1 |
| 5378 | 0 |
| 5379 | JMP SETINT /SET UP INT INITIALLY |
| 5380 | ISZ ONQI /BUMP ARGUMENT POINTER |
| 5381 | ISZ INTQ+1 /BUMP INTERRUPT Q POINTER |
| 5382 | DCA% INTQ+1 /STICK IOT ONTO INT Q |
| 5383 | TAD XSKP /FOLLOWED BY A SKIP |
| 5384 | ISZ INTQ+1 |
| 5385 | DCA% INTQ+1 /ONTO INT Q |
| 5386 | ISZ ONQI /SKIP FIRST WORD OF ADDR |
| 5387 | ISZ INTQ+1 |
| 5388 | ONQISW, TAD% ONQI /GET INT HANDLER ADDRESS |
| 5389 | ISZ ONQI |
| 5390 | DCA% INTADR+1 /ONTO ADDRESS STACK |
| 5391 | TAD INTADR+1 /NOW MAKE JMS% |
| 5392 | AND L177 |
| 5393 | TAD L4600 |
| 5394 | DCA% INTQ+1 /ONTO INT Q |
| 5395 | ISZ INTADR+1 |
| 5396 | ISZ IQSIZE /ROOM FOR MORE? |
| 5397 | JMP% ONQI /YES |
| 5398 | TAD .-1 /NO, CLOSE OUT THE SUBR |
| 5399 | DCA ONQI+1 |
| 5400 | JMP% ONQI |
| 5401 | SETINT, TAD ONQISW /DO THIS PART ONLY ONCE |
| 5402 | DCA ONQI+1 |
| 5403 | CDF |
| 5404 | TAD XSKP /FIX UP #INT |
| 5405 | DCA% XINT+1 /PUT SKIP INST. FIRST |
| 5406 | ISZ XINT+1 |
| 5407 | TAD INTQ+1 |
| 5408 | DCA% XINT+1 /GET ADDR. OF USER'S ROUTINE |
| 5409 | ISZ XINT+1 /ADD TO INTERRUPT CALL |
| 5410 | TAD CIFCDF /GET FIELD INSTRUCTION |
| 5411 | /FIELD1 SECTION INSURES ITS IN FIELD 1 |
| 5412 | DCA% XINT+1 |
| 5413 | CIFCDF, CDF CIF 10 |
| 5414 | JMP ONQI+1 /BACK TO ONQI |
| 5415 | EXTERN #INT |
| 5416 | XINT, ADDR #INT /POINTS TO INT RTN IN COMMON |
| 5417 | INTQ, ADDR IHANDL /MUST USE 15 BIT ADDRESS |
| 5418 | |
| 5419 | |
| 5420 | 5-9 |
| 5421 | \f |
| 5422 | |
| 5423 | |
| 5424 | INTADR, ADDR IHADRS / " |
| 5425 | |
| 5426 | IQSIZE, -5 |
| 5427 | XSKP, SKP |
| 5428 | L177, 177 |
| 5429 | L4600, 4600 |
| 5430 | CDF CIF |
| 5431 | JMP% IHANDL |
| 5432 | IHANDL, 0 |
| 5433 | REPEAT 16 |
| 5434 | JMP IHANDL-2 |
| 5435 | IHADRS, 0;0;0;0;0 /CAN SET UP 1-5 DEVICES |
| 5436 | |
| 5437 | |
| 5438 | ENTRY ONQB /USE "ENTRY" TO PERMIT |
| 5439 | /ACCESS FROM OUTSIDE OF SECTION |
| 5440 | /ROUTINE TO SET UP AN IDLE JOB |
| 5441 | ONQB, 0 |
| 5442 | JMP SETBAK /SETUP #IDLE |
| 5443 | TAD% ONQB /GET ADDRESS OF IDLE JOB |
| 5444 | ONQBSW, ISZ ONQB |
| 5445 | DCA% BAKADR+1 /STORE ONTO BACKGROUND JOB Q |
| 5446 | TAD BAKADR+1 /MAKE A JMS% |
| 5447 | ISZ BAKADR+1 |
| 5448 | AND L177 |
| 5449 | TAD L4600 |
| 5450 | ISZ BAKQ+1 |
| 5451 | DCA% BAKQ+1 |
| 5452 | ISZ BQSIZE /MORE ROOM? |
| 5453 | JMP% ONQB /YES |
| 5454 | TAD .-1 /NO, CLOSE THE DOOR |
| 5455 | DCA ONQB+1 |
| 5456 | JMP% ONQB |
| 5457 | SETBAK, TAD ONQBSW /CLOSE OFF #IDLE INITIALIZATION |
| 5458 | DCA ONQB+1 |
| 5459 | CDF |
| 5460 | TAD XSKP /FIX UP #IDLE |
| 5461 | DCA% XIDLE+1 /ADD SKIP TO IDLE CALL |
| 5462 | TAD BAKQ+1 /GET ADDRESS OF ROUTINE |
| 5463 | ISZ XIDLE+1 |
| 5464 | DCA% XIDLE+1 |
| 5465 | ISZ XIDLE+1 |
| 5466 | TAD CIFCDF /GET FIELD INSTR. |
| 5467 | DCA% XIDLE+1 |
| 5468 | CIF CDF 10 |
| 5469 | JMP ONQB+1 |
| 5470 | EXTERN #IDLE /EXTERNAL REFERENCE |
| 5471 | XIDLE, ADDR #IDLE |
| 5472 | |
| 5473 | BAKQ, ADDR BAKRND |
| 5474 | |
| 5475 | BAKADR, ADDR BHADRS |
| 5476 | |
| 5477 | |
| 5478 | |
| 5479 | 5-10 |
| 5480 | \f |
| 5481 | |
| 5482 | |
| 5483 | BQSIZE, -5 |
| 5484 | CDF CIF |
| 5485 | JMP# BAKRND |
| 5486 | BAKRND, 0 |
| 5487 | REPEAT 6 |
| 5488 | JMP BAKRND-2 |
| 5489 | BHADRS, 0;0;0;0;0 /1-5 JOBS |
| 5490 | |
| 5491 | |
| 5492 | |
| 5493 | |
| 5494 | |
| 5495 | |
| 5496 | |
| 5497 | |
| 5498 | |
| 5499 | |
| 5500 | |
| 5501 | |
| 5502 | |
| 5503 | |
| 5504 | |
| 5505 | |
| 5506 | |
| 5507 | |
| 5508 | |
| 5509 | |
| 5510 | |
| 5511 | |
| 5512 | |
| 5513 | |
| 5514 | |
| 5515 | |
| 5516 | |
| 5517 | |
| 5518 | |
| 5519 | |
| 5520 | |
| 5521 | |
| 5522 | |
| 5523 | |
| 5524 | |
| 5525 | |
| 5526 | |
| 5527 | |
| 5528 | |
| 5529 | |
| 5530 | |
| 5531 | |
| 5532 | |
| 5533 | |
| 5534 | |
| 5535 | |
| 5536 | |
| 5537 | |
| 5538 | 5-11 |
| 5539 | \f |
| 5540 | |
| 5541 | |
| 5542 | APPENDIX A |
| 5543 | |
| 5544 | RALF Assembler Permanent Symbol Table |
| 5545 | |
| 5546 | |
| 5547 | |
| 5548 | Mnemonic Code Mnemonic Code\r ________ ____ ________ ____ |
| 5549 | |
| 5550 | FPP Memory Reference Instructions FPP Special Format Instructions |
| 5551 | |
| 5552 | FADD 1000 ADDX 0110 |
| 5553 | FADDM 5000 ALN 0010 |
| 5554 | FDIV 3000 ATX 0020 |
| 5555 | FLDA 0000 FCLA 0002 |
| 5556 | FMUL 4000 FEXIT 0 |
| 5557 | FMULM 7000 FNEG 0003 |
| 5558 | FSTA 6000 FNOP 0040 |
| 5559 | FSUB 2000 FNORM 0004 |
| 5560 | FPAUSE 0001 |
| 5561 | IOT'S JA 1030 |
| 5562 | JAC 0007 |
| 5563 | FPINT 6551 JAL 1070 |
| 5564 | FPICL 6552 JEQ 1000 |
| 5565 | FPCOM 6553 JGE 1010 |
| 5566 | FPHLT 6554 JGT 1060 |
| 5567 | FPST 6555 JLE 1020 |
| 5568 | FPRST 6556 JLT 1050 |
| 5569 | FPIST 6557 JNE 1040 |
| 5570 | JSA 1120 |
| 5571 | 8-Mode Memory Reference Instructions JSR 1130 |
| 5572 | JXN 2000 |
| 5573 | AND 0000 SETB 1110 |
| 5574 | TAD 1000 SETX 1100 |
| 5575 | ISZ 2000 STARTD 0006 |
| 5576 | DCA 3000 STARTE 0050 |
| 5577 | JMS 4000 STARTF 0005 |
| 5578 | JMP 5000 TRAP3 3000 |
| 5579 | IOT 6000 TRAP4 4000 |
| 5580 | OPR 7000 TRAP5 5000 |
| 5581 | TRAP6 6000 |
| 5582 | TRAP7 7000 |
| 5583 | XTA 0030 |
| 5584 | |
| 5585 | |
| 5586 | |
| 5587 | |
| 5588 | |
| 5589 | |
| 5590 | |
| 5591 | |
| 5592 | |
| 5593 | |
| 5594 | |
| 5595 | |
| 5596 | |
| 5597 | A-1 |
| 5598 | \f |
| 5599 | |
| 5600 | |
| 5601 | Mnemonic\r ________ |
| 5602 | |
| 5603 | Pseudo-Operators |
| 5604 | |
| 5605 | ADDR |
| 5606 | BASE |
| 5607 | COMMON |
| 5608 | COMMZ |
| 5609 | DECIMAL |
| 5610 | DPCHK |
| 5611 | E |
| 5612 | END |
| 5613 | ENTRY |
| 5614 | EXTERN |
| 5615 | F |
| 5616 | FIELD1 |
| 5617 | IFNDEF |
| 5618 | IFNEG |
| 5619 | IFNZRO |
| 5620 | IFPOS |
| 5621 | IFREF |
| 5622 | IFZERO |
| 5623 | INDEX |
| 5624 | LISTOFF |
| 5625 | LISTON |
| 5626 | OCTAL |
| 5627 | ORG |
| 5628 | REPEAT |
| 5629 | SECT |
| 5630 | SECT8 |
| 5631 | TEXT |
| 5632 | ZBLOCK |
| 5633 | IFFLAP |
| 5634 | IFRALF |
| 5635 | IFSW |
| 5636 | IFNSW |
| 5637 | |
| 5638 | |
| 5639 | |
| 5640 | |
| 5641 | |
| 5642 | |
| 5643 | |
| 5644 | |
| 5645 | |
| 5646 | |
| 5647 | |
| 5648 | |
| 5649 | |
| 5650 | |
| 5651 | |
| 5652 | |
| 5653 | |
| 5654 | |
| 5655 | |
| 5656 | A-2 |
| 5657 | \f |
| 5658 | |
| 5659 | |
| 5660 | |
| 5661 | APPENDIX B |
| 5662 | |
| 5663 | ASSEMBLY INSTRUCTIONS for OS/8 |
| 5664 | |
| 5665 | |
| 5666 | The following sequence of commands may be used to assemble the OS/8 |
| 5667 | FORTRAN IV system programs. It is assumed that all PAL language |
| 5668 | sources reside on DSK. In this example, DTA1 is shown as the target |
| 5669 | device, however any other device could be used via the appropriate |
| 5670 | ASSIGN command. Note that PASS2O.SV is produced by conditional |
| 5671 | assembly of PASS2.PA and that the "O" in PASS2O is an oh, not a zero. |
| 5672 | The initial dot and asterisk characters on every command line shown |
| 5673 | are printed by the monitor. All other characters (except carriage |
| 5674 | return, in some cases) are typed by the user. Type CTRL/Z after each |
| 5675 | of the three system pauses at point (1), to continue assembly of |
| 5676 | PASS2O. Type ALT MODE to produce the "$" character. |
| 5677 | |
| 5678 | .ASSIGN DTA1 DEV |
| 5679 | .R PAL8 |
| 5680 | *F4.BN,LIST.LS<F4$ |
| 5681 | .R ABSLDR |
| 5682 | *F4$ |
| 5683 | .SAVE DEV F4=0;12200$ |
| 5684 | .R PAL8 |
| 5685 | *PASS2.BN,LIST.LS<PASS2$ |
| 5686 | .R ABSLDR |
| 5687 | *PASS2$ |
| 5688 | .SAVE DEV PASS2=0;5000$ |
| 5689 | .R PAL8 |
| 5690 | *PASS2O.BN,LIST.LS<TTY:,DSK:PASS2$OVERLY=1 (1) |
| 5691 | .R ABSLDR |
| 5692 | .PASS2O$ |
| 5693 | .SAVE DEV PASS2O=0;7605$ |
| 5694 | .R PAL8 |
| 5695 | *PASS3.BN,LIST.LS<PASS3$ |
| 5696 | .R ABSLDR |
| 5697 | *PASS3$ |
| 5698 | .SAVE DEV PASS3=0;400$ |
| 5699 | .R PAL8 |
| 5700 | *RALF.BN,LIST.LS<RALF$ |
| 5701 | .R ABSLDR |
| 5702 | *RALF$ |
| 5703 | .SAVE DEV RALF=0;200$ |
| 5704 | .R PAL8 |
| 5705 | *LOAD.BN,LIST.LS<LOAD$ |
| 5706 | .R ABSLDR |
| 5707 | *LOAD$ |
| 5708 | .SAVE DEV LOAD=0;200$ |
| 5709 | .R PAL8 |
| 5710 | *FRTS.BN,LIST.LS<RTS,RTL$ |
| 5711 | .R ABSLDR |
| 5712 | *FRTS$ |
| 5713 | .SAVE DEV FRTS=0;200$ |
| 5714 | |
| 5715 | B-1 |
| 5716 | \f |
| 5717 | |
| 5718 | |
| 5719 | .R PAL8 |
| 5720 | *LIBRA.BN,LIST.LS<LIBRA$ |
| 5721 | .R ABSLDR |
| 5722 | *LIBRA$ |
| 5723 | .SAVE DEV LIBRA=0;200$ |
| 5724 | . |
| 5725 | |
| 5726 | |
| 5727 | |
| 5728 | ASSEMBLY INSTRUCTIONS for OS/278 and OS/78 |
| 5729 | |
| 5730 | |
| 5731 | The following BATCH file lists the sequence of commands that may be |
| 5732 | used to assemble the OS/278 FORTRAN IV system programs. All the PAL |
| 5733 | language sources reside on the device assigned to SRCE, and all output |
| 5734 | files go to the device assigned to TARG. The SYS device is used to |
| 5735 | store the binary files until the programs are SAved. Note that |
| 5736 | PASS2O.SV is produced by conditional assembly of PASS2.PA and that the |
| 5737 | "O" in PASS2O is an oh, not a zero. |
| 5738 | |
| 5739 | If these commands are typed in, the initial "}" and asterisk (*) |
| 5740 | characters on every command line shown are printed by the monitor. |
| 5741 | All other characters (except carriage return, in some cases) are typed |
| 5742 | by the user. |
| 5743 | |
| 5744 | To use these commands with OS/78, replace the "}" with a ".". |
| 5745 | |
| 5746 | |
| 5747 | $JOB (FORGEN.BI) ASSEMBLE FORTRAN IV FOR OS278 |
| 5748 | |
| 5749 | /}ASSIGN XXX SRCE where XXX is the device containing the source files |
| 5750 | /}ASSIGN YYY TARG where YYY is the output device for the .SV files |
| 5751 | |
| 5752 | }PAL F4<SRCE:F4 |
| 5753 | }LOAD F4 |
| 5754 | }SAVE TARG:F4.SV;12200=100 |
| 5755 | }DELETE F4.BN |
| 5756 | |
| 5757 | }PAL PASS2<SRCE:PASS2 |
| 5758 | }LOAD PASS2 |
| 5759 | }SAVE TARG:PASS2.SV;5000=100 |
| 5760 | }DELETE PASS2.BN |
| 5761 | |
| 5762 | }PAL PASS2O<SRCE:PASS2O,PASS2 |
| 5763 | }LOAD PASS2O |
| 5764 | }SAVE TARG:PASS2O.SV;7605=100 |
| 5765 | }DELETE PASS2O.BN |
| 5766 | |
| 5767 | }PAL PASS3<SRCE:PASS3 |
| 5768 | }LOAD PASS3 |
| 5769 | }SAVE TARG:PASS3.SV;400=100 |
| 5770 | }DELETE PASS3.BN |
| 5771 | |
| 5772 | |
| 5773 | |
| 5774 | B-2 |
| 5775 | \f |
| 5776 | |
| 5777 | |
| 5778 | }PAL LOAD<SRCE:LOAD |
| 5779 | }LOAD LOAD |
| 5780 | }SAVE TARG:LOAD.SV;200=100 |
| 5781 | }DELETE LOAD.BN |
| 5782 | |
| 5783 | }PAL FRTS<SRCE:RTS,RTL /W/K |
| 5784 | }LOAD FRTS |
| 5785 | }SAVE TARG:FRTS.SV;200=100 |
| 5786 | }DELETE FTRS.BN |
| 5787 | |
| 5788 | }PAL RALF<SRCE:RALF /W |
| 5789 | }LOAD RALF |
| 5790 | }SAVE TARG:RALF.SV;200=100 |
| 5791 | }DELETE RALF.BN |
| 5792 | |
| 5793 | }PAL LIBRA<SRCE:LIBRA |
| 5794 | }LOAD LIBRA |
| 5795 | }SAVE TARG:LIBRA.SV;200=100 |
| 5796 | }DELETE LIBRA.BN |
| 5797 | |
| 5798 | $END |
| 5799 | |
| 5800 | |
| 5801 | |
| 5802 | |
| 5803 | |
| 5804 | |
| 5805 | |
| 5806 | |
| 5807 | |
| 5808 | |
| 5809 | |
| 5810 | |
| 5811 | |
| 5812 | |
| 5813 | |
| 5814 | |
| 5815 | |
| 5816 | |
| 5817 | |
| 5818 | |
| 5819 | |
| 5820 | |
| 5821 | |
| 5822 | |
| 5823 | |
| 5824 | |
| 5825 | |
| 5826 | |
| 5827 | |
| 5828 | |
| 5829 | |
| 5830 | |
| 5831 | |
| 5832 | |
| 5833 | B-3 |
| 5834 | \f |
| 5835 | |
| 5836 | |
| 5837 | |
| 5838 | INDEX |
| 5839 | |
| 5840 | |
| 5841 | |
| 5842 | Argument passing, 2-7 Idle jobs, 4-1 |
| 5843 | Arithmetic expression Indirect addressing, 2-5 |
| 5844 | analyzer, 1-1 Interrupts, |
| 5845 | Servicing, 4-1, 4-14 |
| 5846 | Spurious, 4-14 |
| 5847 | Background Jobs, 4-1 |
| 5848 | Binary buffer table, 3-9 |
| 5849 | Binary section table, 3-10 Keyword, 1-1 |
| 5850 | Block count sequence number, 4-13 |
| 5851 | |
| 5852 | LIBRA, 5-2 |
| 5853 | COMMON information block, 1-7 Library, 2-1 |
| 5854 | Communication, 2-7 Format, 5-1 |
| 5855 | COMMZ sections, 2-10 Line printer handler, 4-13 |
| 5856 | Compilation, 1-1 Literals, 1-4, 1-5 |
| 5857 | Compiler symbol table, 1-2 Loader, 3-1 |
| 5858 | Core maps, 3-2 to 3-4 |
| 5859 | Image file, 3-13 |
| 5860 | Device handlers, 4-14 Subroutines, |
| 5861 | Device flag handlers, 4-2 Loader symbol table, 3-1, 3-7 |
| 5862 | Dimension information block, 1-5 |
| 5863 | DSRN table, 4-8 |
| 5864 | Magic number, 1-5 |
| 5865 | Mixing code, 2-6 |
| 5866 | Module, 2-1 |
| 5867 | Entry point, 2-1 Module count table, 3-12 |
| 5868 | EQUIVALENCE information table, Module descriptor table, 3-11 |
| 5869 | 1-6 |
| 5870 | ESD, 2-1, 2-2, 2-4 |
| 5871 | ESD correspondence table, 3-9 Off-page references, 2-17 |
| 5872 | External symbol, 2-2 Optimized code, 2-9 |
| 5873 | External symbol dictionary, 2-1, Output codes, 1-7 |
| 5874 | 2-2, 2-4 Overlay table, 3-10 |
| 5875 | |
| 5876 | |
| 5877 | FIELD1 sections, 2-11 /P option, 4-20 |
| 5878 | Files, 4-9 Page boundaries, 2-11 |
| 5879 | Formatted I/O, 4-9 PASS1, 1-1 |
| 5880 | FRTS Output, 1-7 |
| 5881 | Calling sequence, 4-3 Subroutines, 1-10 |
| 5882 | Core maps, 4-5 to 4-7 PASS2, 1-12 |
| 5883 | Entry points, 4-4 Error list, 1-14 |
| 5884 | Initialization, 4-13 Skeleton tables, 1-14 |
| 5885 | Page zero, 4-10 Symbol table, 1-14 |
| 5886 | Subroutines, 1-16 |
| 5887 | Header block, 3-13 Pass3, 1-17 |
| 5888 | |
| 5889 | |
| 5890 | |
| 5891 | |
| 5892 | X-1 |
| 5893 | \f |
| 5894 | |
| 5895 | |
| 5896 | PDP-8 code, 2-5 |
| 5897 | Program loading, 3-9 |
| 5898 | Program termination, 4-21 |
| 5899 | Pseudo-ops, 2-3 to 2-6, |
| 5900 | 2-16 to 2-18, 5-3 |
| 5901 | |
| 5902 | |
| 5903 | RALF, 2-1 |
| 5904 | Expressions, 2-3 |
| 5905 | Symbol table, 2-3 |
| 5906 | RALF output file, 2-4 |
| 5907 | |
| 5908 | |
| 5909 | Section, 2-1 |
| 5910 | Section types, 2-9 |
| 5911 | Statement number, 1-3 |
| 5912 | Subroutine calls, 2-7 |
| 5913 | Subroutine return sequence, 2-8 |
| 5914 | Symbol table, |
| 5915 | Compiler, 1-14 |
| 5916 | Loader, 3-7 |
| 5917 | RALF, 2-4 |
| 5918 | |
| 5919 | |
| 5920 | Termination, program, 4-21 |
| 5921 | Text, 2-1 |
| 5922 | TRAP3 and TRAP4, 2-6 |
| 5923 | |
| 5924 | |
| 5925 | Variable type word, 1-2 |
| 5926 | |
| 5927 | |
| 5928 | 8-mode sections, 2-11 |
| 5929 | |
| 5930 | |
| 5931 | |
| 5932 | |
| 5933 | |
| 5934 | |
| 5935 | |
| 5936 | |
| 5937 | |
| 5938 | |
| 5939 | |
| 5940 | |
| 5941 | |
| 5942 | |
| 5943 | |
| 5944 | |
| 5945 | |
| 5946 | |
| 5947 | |
| 5948 | |
| 5949 | |
| 5950 | |
| 5951 | X-2 |
| 5952 | \f |
| 5953 | |
| 5954 | |
| 5955 | DEC-S8-LFSSA-A-D |
| 5956 | OS/8 FORTRAN IV |
| 5957 | SOFTWARE SUPPORT MANUAL |
| 5958 | |
| 5959 | |
| 5960 | READER'S COMMENTS |
| 5961 | |
| 5962 | |
| 5963 | Digital Equipment Corporation maintains a continuous effort to improve |
| 5964 | the quality and usefulness of its publications. To do this effectively |
| 5965 | we need user feedback--your critical evaluation of this document. |
| 5966 | |
| 5967 | |
| 5968 | Did you find errors in this document? If so, please specify by page. |
| 5969 | |
| 5970 | ______________________________________________________________________ |
| 5971 | ______________________________________________________________________ |
| 5972 | ______________________________________________________________________ |
| 5973 | ______________________________________________________________________ |
| 5974 | ______________________________________________________________________ |
| 5975 | |
| 5976 | |
| 5977 | How can this document be improved? |
| 5978 | |
| 5979 | ______________________________________________________________________ |
| 5980 | ______________________________________________________________________ |
| 5981 | ______________________________________________________________________ |
| 5982 | ______________________________________________________________________ |
| 5983 | ______________________________________________________________________ |
| 5984 | |
| 5985 | |
| 5986 | How does this document compare with other technical documents you |
| 5987 | have read? |
| 5988 | |
| 5989 | ______________________________________________________________________ |
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| 5992 | ______________________________________________________________________ |
| 5993 | ______________________________________________________________________ |
| 5994 | |
| 5995 | |
| 5996 | |
| 5997 | Job Title_________________________________ Date:______________________ |
| 5998 | |
| 5999 | Name:__________________________ Organization:_________________________ |
| 6000 | |
| 6001 | Street:________________________ Department:___________________________ |
| 6002 | |
| 6003 | City:_________________ State:___________ Zip or Country_______________ |
| 6004 | |
| 6005 | |
| 6006 | |
| 6007 | |
| 6008 | |
| 6009 | |
| 6010 | |
| 6011 | \f |
| 6012 | |
| 6013 | |
| 6014 | |
| 6015 | |
| 6016 | |
| 6017 | |
| 6018 | |
| 6019 | |
| 6020 | |
| 6021 | |
| 6022 | |
| 6023 | |
| 6024 | |
| 6025 | |
| 6026 | |
| 6027 | |
| 6028 | |
| 6029 | |
| 6030 | |
| 6031 | -------------------------------Fold Here------------------------------ |
| 6032 | |
| 6033 | |
| 6034 | |
| 6035 | |
| 6036 | |
| 6037 | |
| 6038 | |
| 6039 | |
| 6040 | |
| 6041 | |
| 6042 | |
| 6043 | |
| 6044 | |
| 6045 | |
| 6046 | |
| 6047 | |
| 6048 | |
| 6049 | -----------------Do Not Tear - Fold Here and Staple------------------- |
| 6050 | |
| 6051 | +---------------+ |
| 6052 | | FIRST CLASS | |
| 6053 | | PERMIT NO. 33 | |
| 6054 | | MAYNARD. MASS.| |
| 6055 | +---------------+ |
| 6056 | BUSINESS REPLY MAIL ======== |
| 6057 | NO POSTAGE STAMP NECESSARY IF MAILED IN THE UNITED STATES ======== |
| 6058 | ====================================================================== |
| 6059 | Postage will be paid by: ======== |
| 6060 | ======== |
| 6061 | +-+-+-+-+-+-+-+ ======== |
| 6062 | |d|i|g|i|t|a|l| ======== |
| 6063 | +-+-+-+-+-+-+-+ ======== |
| 6064 | Digital Equipment Corporation ======== |
| 6065 | Software Information Service ======== |
| 6066 | Software Engineering and Services ======== |
| 6067 | Maynard, Massachusetts 01754 ======== |
| 6068 | |