[h316.git] / lib / hachti / src / stack.asm

* H316 SAFE SOFTWARE STACK, REV. 0.1
*
*
* AUTHOR: 
* 
*       PHILIPP HACHTMANN, 2007
* 
* VERSIONS:
* 
*               0.1 - INITIAL REVISION (22.12.2007)
* 
* PURPOSE:
* 
*       TO PROVIDE A MULTI-PURPOSE STACK MECHANISM
*       TO PROVIDE A SPECIAL-PURPOSE STACK MECHANISM FOR RECURSIVE
*       PROGRAM CALLS
*
* THEORY OF OPERATION:
* 
* THE STACK ROUTINES MAINTAIN AN UPWARDS GROWING STACK.
* EVERY USAGE CONTEXT OF THE STACK NEEDS TO RESERVE THE SPACE FOR
* ITS STACK'S DATA. THIS ENABLES THE PROGRAMMER TO CHOOSE THE STACK
* SIZE AND USE MULTIPLE STACKS IN MULTIPLE PLACES INDEPENDENTLY.
* ALL STACK RELATED ROUTINES TAKE A POINTER TO THE STACK'S INTERNAL
* DATA AS FIRST ARGUMENT.
* 
* THE DATA LAYOUT OF THE STACK DATA IS AS FOLLOWING:
* 
* SIZE  OCT     '1000   SIZE OF THE STACK IN MACHINE WORDS
* PTR   DAC     **      THE STACK POINTER
* FILL  DAC     **      THE FILL COUNTER
* OVER  DAC     OFL     OPTIONAL POINTER TO OVERFLOW ERROR ROUTINE
* UNDR  DAC     UFL     OPTIONAL POINTER TO UNDERFLOW ERROR ROUTINE
* STCK  BSS     '1000   THE STACK DATA
* 
* IF CUSTOM ERROR HANDLING ROUTINES ARE NOT TO BE USED, SET THE TWO
* POINTER LOCATIONS TO ZERO. THEN, INTERNAL ERROR ROUTINES WILL BE
* USED. SIZE AND THE FUNCTION POINTERS HAVE TO BE INITIALISED. THE
* OTHER LOCATIONS ARE INITIALISED BY THE STACK ROUTINES.
* 
* USAGE:
* 
* INITIALISING STACK POINTER:
*       
*       CALL    S$INIT
*       DAC     SDATA   STACK DATA
*       DAC     SSIZ    DATA SIZE (NOT STACK DEPTH!!!)
*       DAC     0
*  
* PUSHING AND POPPING THE A-REGISTER FROM AND TO THE STACK:
* 
*       CALL    S$PUSH  VALUE IN A REGISTER IS PUSHED.
*       DAC     SDATA
* 
*       CALL    $$POP  VALUE FROM STACK IS POPPED INTO A-REGISTER.
*       DAC     SDATA
* 
* PUSHING AND POPPING ARBITRARY DATA FROM AND TO THE STACK:
* 
*       CALL    S$PUSM
*       DAC     SDATA
*       DAC     ADDRESS
*       OCT     SIZE
*  
*       CALL    S$POPM
*       DAC     SDATA
*       DAC     ADDRESS
*       OCT     SIZE
*
* 
* MAKING A RECURSIVE CALL FROM FORTRAN IV TO A FORTRAN IV OR OTHER ROUTINE:
* 
* THE ROUTINE S$CALL SAVES A SET OF LOCAL VARIABLES ONTO THE STACK.
* IT ALSO SAVES THE RETURN ADDRESS AND ITS OWN PARAMETERS.
* S$LLAC DOES EVERYTHING IN REVERSE ORDER.
* 
* HERE IS AN EXAMPLE HOW TO USE THE TWO ROUTINES IN FORTRAN IV:
* 
* C LOCAL VARIABLES I(3),A,Z TO SAVE
* 
*       CALL S$CALL(3,I,3,A,2,Z,2)
*       RETURN    <-- FOR THE RETURN ADDRESS OF THE CURRENT ROUTINE
*       CALL MYROUTINE(...)
*       CALL S$LLAC
* 
* ASSEMBLER CALLING SEQUENCE:
*       
*       JST     S$CALL
*       DAC     VARNO  NO OF LOCAL VARIABLES TO SAVE ON THE STACK
*       DAC     VAR1   POINTER TO FIRST VARIABLE
*       DAC     SIZE1  WORD SIZE OF VARIABLE
*       ...
*       DAC     VARN    POINTER TO LAST VARIABLE
*       DAC     SIZEN   WORD SIZE OF LAST VARIABLE
*       DAC     0       FORTRAN IV COMPILER GENERATED
* 
*       JMP*    PROC    RETURN JUMP, GENERATED BY THE "RETURN" STATEMENT
* 
*       JST     MYROUTINE
*       ...
* 
*       JST     S$LLAC
* 
*  
********************************************************************************
*
* 
**** SYMBOL DECLARATIONS
* 
	SUBR	STACK,SBUF	JUST A LABEL FOR THE OBJECT TAPE
	SUBR	S$INIT,INIT	INITIALIZATION
	SUBR	S$PUSH,PUSH	SINGLE WORD PUSH
	SUBR	S$POP,POP	SINGLE WORD POP
	SUBR	S$PUSM,PUSM	MEMORY RANGE PUSH
	SUBR	S$POPM,POPM	MEMORY RANGE POP
	SUBR	S$PTR,SPTR	STACK POINTER ACCESS
	SUBR	S$CALL,CALL
	SUBR	S$LLAC,LLAC
* 
* 	
********************************************************************************
* 
* 
	REL		RELOCATEABLE OBJECT
*  
* 
********************************************************************************
*
* *** PUSH MEMORY RANGE TO STACK
* 
PUSM	DAC	**	ENTRY POINT TO PUSH ROUTINE
	STA	ATM1	SAVE A-REGISTER
* 
	LDA*	PUSM	LOAD DATA BASE
	IRS	PUSM
	STA	DPT	SAVE FOR LATER USE
* 
	LDA*	PUSM	LOAD POINTER
	STA	PTR	STORE TO TRANSFER POINTER
	IRS	PUSM	GO TO NEXT ARGUMENT
	LDA*	PUSM	LOAD TRANSFER SIZE
	IRS	PUSM	CORRECT RETURN ADDRESS
* 
	TCA		NEGATE WORD COUNT
	STA	CNT	STORE TO COUNTER
* 
PULP	LDA*	PTR	GET DATA
	JST	PUSH	PUSH IT!
DPT	DAC	**
* 
	IRS	PTR	INCREMENT POINTER
	IRS	CNT	INCREMENT BYTE COUNTER
	JMP	PULP	DO IT AGAIN!
* 
	LDA	ATM1	RESTORE A-REG
	JMP*	PUSM	RETURN
* 
*
********************************************************************************
*
* 
**** POP MEMORY RANGE FROM STACK
* 
POPM	DAC	**	ENTRY POINT TO PUSH ROUTINE
	STA	ATM1	SAVE A-REGISTER
* 
 	LDA*	POPM	GET DATA POINTER
	IRS	POPM
	STA	DPTR	STORE FOR LATER USE
*
	LDA*	POPM	LOAD POINTER
	IRS	POPM	GO TO NEXT ARGUMENT
	ADD*	POPM	ADD TRANSFER SIZE
	SUB	=1	SUBSTRACT 1 TO GET HIGH ADDRESS
	STA	PTR	STORE TO TRANSFER POINTER
	LDA*	POPM	LOAD TRANSFER SIZE
	IRS	POPM	CORRECT RETURN ADDRESS
* 
	TCA		NEGATE WORD COUNT
	STA	CNT	STORE TO COUNTER
* 
POLP	JST	POP	POP DATA FROM THE STACK
DPTR	DAC	**
* 
	STA*	PTR	STORE IT.
	LDA	PTR
	SUB	=1	DECREMENT
	STA	PTR	WRITE BACK
	IRS	CNT	INCREMENT BYTE COUNTER
	JMP	POLP	DO IT AGAIN!
* 
	LDA	ATM1	RESTORE A-REG
	JMP*	POPM	RETURN
* 
*
********************************************************************************
*
* 
**** PUSH SINGLE WORD ONTO STACK
* 
	SUBR	PUSH
PUSH	DAC	**	REAL PUSH ROUTINE - PUSH AC TO STACK.
* 	 
	STX	XTM	SAVE X REGISTER
	STA	ATM2	SAVE A REGISTER
* 
	LDX*	PUSH	LOAD INDEX REGISTER WITH DATA BASE
	IRS	PUSH
* 
	LDA	FILL,1	LOAD FILL SIZE
	CAS	SSIZ,1	COMPARE STACK SIZE
	NOP
	JST	OFLO	OVERFLOW!
*  
	LDA	ATM2
	STA*	SPTR,1	NO OVERFLOW, PUT DATA ONTO STACK
	IRS	SPTR,1	INCREMENT STACK POINTER
	IRS	FILL,1	INCREMENT FILL SIZE
* 
	LDX	XTM	RESTORE X REGISTER
	LDA	ATM2
	JMP*	PUSH	RETURN WITH A-REG UNALTERED.
* 
* 
********************************************************************************
* 
* 
**** POP SINGLE WORD FROM STACK
* 
POP	DAC	**	REAL POP ROUTINE - POP AC FROM STACK.
* 
	STX	XTM	SAVE X REGISTER
	LDX*	POP	LOAD INDEX REGISTER WITH DATA BASE
	IRS	POP
* 
	LDA	FILL,1	FILL SIZE
	SNZ
	JST	UFLO	NOTHING INSIDE? SKIP!
* 
	LDA	SPTR,1	LOAD STACK POINTER
	SUB	=1	DECREMENT IT TO LAST USED LOCATION
	STA	SPTR,1	SAVE IT BACK
	LDA	FILL,1
	SUB	=1
	STA	FILL,1	DECREMENT FILL SIZE
* 
	LDA*	SPTR,1	LOAD VALUE FROM THE STACK
	LDX	XTM	RESTORE INDEX REGISTER
	JMP*	POP	RETURN.
* 
* 
******************************************************************************** 
*
* 
**** INITIALIZATION
* 
INIT	DAC	**	INITIALIZE STACK
	STA	ATM1
	STX	XTM
* 
	LDX*	INIT
* 
	LDA	VARS	SIZE OF MANAGEMENT VARIABLES
	ADD*	INIT	BASE ADDRESS
	STA	SPTR,1	SAVE TO STACK POINTER
	IRS	INIT
* 
	LDA*	INIT	LOAD DATA POOL SIZE POINTER
	STA	PTR	DEREFERENCE POINTER
	LDA*	PTR	LOAD DATA POOL SIZE
	SUB	VARS	VARIABLE SIZE
	STA	SSIZ,1	SAVE TO STACK DEPTH
* 
	CRA
	STA	FILL,1
* 
	LDA	ATM1
	LDX	XTM
	IRS	INIT
	IRS	INIT	FOR FORTRAN COMPATIBILITY
	JMP*	INIT
* 
*
********************************************************************************
* 
*  
**** ERROR HANDLING ROUTINES
* 
	SUBR	OFLO
OFLO	DAC	**	STACK OVERFLOW ROUTINE
	LDA	OMSP	LOAD OVERFLOW MESSAGE POINTER
	JST	TYPE	TYPE IT OUT.
* 
	HLT		WHAT WE DO: HALT THE MACHINE.
	JMP	*-1	YOU CANNOT SIMPLY LEAVE THIS, IT'S SERIOUS!
* 
* 
****************************************
* 
* 
	SUBR	UFLO
UFLO	DAC	**	STACK OVERFLOW ROUTINE
	LDA	UMSP	LOAD OVERFLOW MESSAGE POINTER
	JST	TYPE	TYPE IT OUT.
* 
	HLT		WHAT WE DO: HALT THE MACHINE.
	JMP	*-1	YOU CANNOT SIMPLY LEAVE THIS, IT'S SERIOUS!
* 
* 
****************************************
* 
* 
	SUBR	TYPE
TYPE	DAC	**
	SKS	'104	TEST ASR READY
	JMP	*-1	WAIT TO BECOME READY
	OCP	'104	SET TO OUTPUT MODE
* 
	STA	PTR	STORE POINTER
* 
TLOP	LDA*	PTR	TYPE LOOP
	SNZ		TEST FOR END
	JMP*	TYPE	RETURN
	ICA	
	OTA	'4
	JMP	*-1
	ICA
	OTA	'4
	JMP	*-1
	SKS	'104	ADDITIONAL TEST FOR READY
	JMP	*-1
	IRS	PTR	NEXT WORD.
	JMP	TLOP
* 
* 
********************************************************************************
*
* 
***** VARIABLES
* 
* 
PTR	DEC	0	TRANSFER POINTER TO USER BUFFERS
CNT	DEC	0	TRANSFER COUNTER
* 
ATM1	DEC	0	A-REGISTER BACKUP
ATM2	DEC	0	A-REGISTER BACKUP
XTM	DEC	0	X-REGISTER BACKUP
* 
* 
***** CONSTANTS
*
VARS	DEC	3	SIZE OF VARIABLES AT BEGINNING OF DATA
* 
SSIZ	EQU	0
SPTR	EQU	1	 
FILL	EQU	2
* 
OMSP	DAC	OMSG		POINTER TO MESSAGE
UMSP	DAC	UMSG		POINTER TO MESSAGE
OMSG	OCT	'006412		CR/LF CHARACTERS
	BCI	16,STACK OVERFLOW, YOUR'RE SCREWED!
	DEC	0		TERMINATION CHARACTER
UMSG	OCT	'006412		CR/LF CHARACTERS
	BCI	17,STACK UNDERFLOW, YOUR'RE SCREWED!
	DEC	0		TERMINATION CHARACTER
*       
* 
********************************************************************************
*
* 
	END			THAT'S IT.
Commit	Line	Data
	1	* H316 SAFE SOFTWARE STACK, REV. 0.1
	2	*
	3	*
	4	* AUTHOR:
	5	*
	6	* PHILIPP HACHTMANN, 2007
	7	*
	8	* VERSIONS:
	9	*
	10	* 0.1 - INITIAL REVISION (22.12.2007)
	11	*
	12	* PURPOSE:
	13	*
	14	* TO PROVIDE A MULTI-PURPOSE STACK MECHANISM
	15	* TO PROVIDE A SPECIAL-PURPOSE STACK MECHANISM FOR RECURSIVE
	16	* PROGRAM CALLS
	17	*
	18	* THEORY OF OPERATION:
	19	*
	20	* THE STACK ROUTINES MAINTAIN AN UPWARDS GROWING STACK.
	21	* EVERY USAGE CONTEXT OF THE STACK NEEDS TO RESERVE THE SPACE FOR
	22	* ITS STACK'S DATA. THIS ENABLES THE PROGRAMMER TO CHOOSE THE STACK
	23	* SIZE AND USE MULTIPLE STACKS IN MULTIPLE PLACES INDEPENDENTLY.
	24	* ALL STACK RELATED ROUTINES TAKE A POINTER TO THE STACK'S INTERNAL
	25	* DATA AS FIRST ARGUMENT.
	26	*
	27	* THE DATA LAYOUT OF THE STACK DATA IS AS FOLLOWING:
	28	*
	29	* SIZE OCT '1000 SIZE OF THE STACK IN MACHINE WORDS
	30	* PTR DAC ** THE STACK POINTER
	31	* FILL DAC ** THE FILL COUNTER
	32	* OVER DAC OFL OPTIONAL POINTER TO OVERFLOW ERROR ROUTINE
	33	* UNDR DAC UFL OPTIONAL POINTER TO UNDERFLOW ERROR ROUTINE
	34	* STCK BSS '1000 THE STACK DATA
	35	*
	36	* IF CUSTOM ERROR HANDLING ROUTINES ARE NOT TO BE USED, SET THE TWO
	37	* POINTER LOCATIONS TO ZERO. THEN, INTERNAL ERROR ROUTINES WILL BE
	38	* USED. SIZE AND THE FUNCTION POINTERS HAVE TO BE INITIALISED. THE
	39	* OTHER LOCATIONS ARE INITIALISED BY THE STACK ROUTINES.
	40	*
	41	* USAGE:
	42	*
	43	* INITIALISING STACK POINTER:
	44	*
	45	* CALL S$INIT
	46	* DAC SDATA STACK DATA
	47	* DAC SSIZ DATA SIZE (NOT STACK DEPTH!!!)
	48	* DAC 0
	49	*
	50	* PUSHING AND POPPING THE A-REGISTER FROM AND TO THE STACK:
	51	*
	52	* CALL S$PUSH VALUE IN A REGISTER IS PUSHED.
	53	* DAC SDATA
	54	*
	55	* CALL $$POP VALUE FROM STACK IS POPPED INTO A-REGISTER.
	56	* DAC SDATA
	57	*
	58	* PUSHING AND POPPING ARBITRARY DATA FROM AND TO THE STACK:
	59	*
	60	* CALL S$PUSM
	61	* DAC SDATA
	62	* DAC ADDRESS
	63	* OCT SIZE
	64	*
	65	* CALL S$POPM
	66	* DAC SDATA
	67	* DAC ADDRESS
	68	* OCT SIZE
	69	*
	70	*
	71	* MAKING A RECURSIVE CALL FROM FORTRAN IV TO A FORTRAN IV OR OTHER ROUTINE:
	72	*
	73	* THE ROUTINE S$CALL SAVES A SET OF LOCAL VARIABLES ONTO THE STACK.
	74	* IT ALSO SAVES THE RETURN ADDRESS AND ITS OWN PARAMETERS.
	75	* S$LLAC DOES EVERYTHING IN REVERSE ORDER.
	76	*
	77	* HERE IS AN EXAMPLE HOW TO USE THE TWO ROUTINES IN FORTRAN IV:
	78	*
	79	* C LOCAL VARIABLES I(3),A,Z TO SAVE
	80	*
	81	* CALL S$CALL(3,I,3,A,2,Z,2)
	82	* RETURN <-- FOR THE RETURN ADDRESS OF THE CURRENT ROUTINE
	83	* CALL MYROUTINE(...)
	84	* CALL S$LLAC
	85	*
	86	* ASSEMBLER CALLING SEQUENCE:
	87	*
	88	* JST S$CALL
	89	* DAC VARNO NO OF LOCAL VARIABLES TO SAVE ON THE STACK
	90	* DAC VAR1 POINTER TO FIRST VARIABLE
	91	* DAC SIZE1 WORD SIZE OF VARIABLE
	92	* ...
	93	* DAC VARN POINTER TO LAST VARIABLE
	94	* DAC SIZEN WORD SIZE OF LAST VARIABLE
	95	* DAC 0 FORTRAN IV COMPILER GENERATED
	96	*
	97	* JMP* PROC RETURN JUMP, GENERATED BY THE "RETURN" STATEMENT
	98	*
	99	* JST MYROUTINE
	100	* ...
	101	*
	102	* JST S$LLAC
	103	*
	104	*
	105	********************************************************************************
	106	*
	107	*
	108	**** SYMBOL DECLARATIONS
	109	*
	110	SUBR STACK,SBUF JUST A LABEL FOR THE OBJECT TAPE
	111	SUBR S$INIT,INIT INITIALIZATION
	112	SUBR S$PUSH,PUSH SINGLE WORD PUSH
	113	SUBR S$POP,POP SINGLE WORD POP
	114	SUBR S$PUSM,PUSM MEMORY RANGE PUSH
	115	SUBR S$POPM,POPM MEMORY RANGE POP
	116	SUBR S$PTR,SPTR STACK POINTER ACCESS
	117	SUBR S$CALL,CALL
	118	SUBR S$LLAC,LLAC
	119	*
	120	*
	121	********************************************************************************
	122	*
	123	*
	124	REL RELOCATEABLE OBJECT
	125	*
	126	*
	127	********************************************************************************
	128	*
	129	* *** PUSH MEMORY RANGE TO STACK
	130	*
	131	PUSM DAC ** ENTRY POINT TO PUSH ROUTINE
	132	STA ATM1 SAVE A-REGISTER
	133	*
	134	LDA* PUSM LOAD DATA BASE
	135	IRS PUSM
	136	STA DPT SAVE FOR LATER USE
	137	*
	138	LDA* PUSM LOAD POINTER
	139	STA PTR STORE TO TRANSFER POINTER
	140	IRS PUSM GO TO NEXT ARGUMENT
	141	LDA* PUSM LOAD TRANSFER SIZE
	142	IRS PUSM CORRECT RETURN ADDRESS
	143	*
	144	TCA NEGATE WORD COUNT
	145	STA CNT STORE TO COUNTER
	146	*
	147	PULP LDA* PTR GET DATA
	148	JST PUSH PUSH IT!
	149	DPT DAC **
	150	*
	151	IRS PTR INCREMENT POINTER
	152	IRS CNT INCREMENT BYTE COUNTER
	153	JMP PULP DO IT AGAIN!
	154	*
	155	LDA ATM1 RESTORE A-REG
	156	JMP* PUSM RETURN
	157	*
	158	*
	159	********************************************************************************
	160	*
	161	*
	162	**** POP MEMORY RANGE FROM STACK
	163	*
	164	POPM DAC ** ENTRY POINT TO PUSH ROUTINE
	165	STA ATM1 SAVE A-REGISTER
	166	*
	167	LDA* POPM GET DATA POINTER
	168	IRS POPM
	169	STA DPTR STORE FOR LATER USE
	170	*
	171	LDA* POPM LOAD POINTER
	172	IRS POPM GO TO NEXT ARGUMENT
	173	ADD* POPM ADD TRANSFER SIZE
	174	SUB =1 SUBSTRACT 1 TO GET HIGH ADDRESS
	175	STA PTR STORE TO TRANSFER POINTER
	176	LDA* POPM LOAD TRANSFER SIZE
	177	IRS POPM CORRECT RETURN ADDRESS
	178	*
	179	TCA NEGATE WORD COUNT
	180	STA CNT STORE TO COUNTER
	181	*
	182	POLP JST POP POP DATA FROM THE STACK
	183	DPTR DAC **
	184	*
	185	STA* PTR STORE IT.
	186	LDA PTR
	187	SUB =1 DECREMENT
	188	STA PTR WRITE BACK
	189	IRS CNT INCREMENT BYTE COUNTER
	190	JMP POLP DO IT AGAIN!
	191	*
	192	LDA ATM1 RESTORE A-REG
	193	JMP* POPM RETURN
	194	*
	195	*
	196	********************************************************************************
	197	*
	198	*
	199	**** PUSH SINGLE WORD ONTO STACK
	200	*
	201	SUBR PUSH
	202	PUSH DAC ** REAL PUSH ROUTINE - PUSH AC TO STACK.
	203	*
	204	STX XTM SAVE X REGISTER
	205	STA ATM2 SAVE A REGISTER
	206	*
	207	LDX* PUSH LOAD INDEX REGISTER WITH DATA BASE
	208	IRS PUSH
	209	*
	210	LDA FILL,1 LOAD FILL SIZE
	211	CAS SSIZ,1 COMPARE STACK SIZE
	212	NOP
	213	JST OFLO OVERFLOW!
	214	*
	215	LDA ATM2
	216	STA* SPTR,1 NO OVERFLOW, PUT DATA ONTO STACK
	217	IRS SPTR,1 INCREMENT STACK POINTER
	218	IRS FILL,1 INCREMENT FILL SIZE
	219	*
	220	LDX XTM RESTORE X REGISTER
	221	LDA ATM2
	222	JMP* PUSH RETURN WITH A-REG UNALTERED.
	223	*
	224	*
	225	********************************************************************************
	226	*
	227	*
	228	**** POP SINGLE WORD FROM STACK
	229	*
	230	POP DAC ** REAL POP ROUTINE - POP AC FROM STACK.
	231	*
	232	STX XTM SAVE X REGISTER
	233	LDX* POP LOAD INDEX REGISTER WITH DATA BASE
	234	IRS POP
	235	*
	236	LDA FILL,1 FILL SIZE
	237	SNZ
	238	JST UFLO NOTHING INSIDE? SKIP!
	239	*
	240	LDA SPTR,1 LOAD STACK POINTER
	241	SUB =1 DECREMENT IT TO LAST USED LOCATION
	242	STA SPTR,1 SAVE IT BACK
	243	LDA FILL,1
	244	SUB =1
	245	STA FILL,1 DECREMENT FILL SIZE
	246	*
	247	LDA* SPTR,1 LOAD VALUE FROM THE STACK
	248	LDX XTM RESTORE INDEX REGISTER
	249	JMP* POP RETURN.
	250	*
	251	*
	252	********************************************************************************
	253	*
	254	*
	255	**** INITIALIZATION
	256	*
	257	INIT DAC ** INITIALIZE STACK
	258	STA ATM1
	259	STX XTM
	260	*
	261	LDX* INIT
	262	*
	263	LDA VARS SIZE OF MANAGEMENT VARIABLES
	264	ADD* INIT BASE ADDRESS
	265	STA SPTR,1 SAVE TO STACK POINTER
	266	IRS INIT
	267	*
	268	LDA* INIT LOAD DATA POOL SIZE POINTER
	269	STA PTR DEREFERENCE POINTER
	270	LDA* PTR LOAD DATA POOL SIZE
	271	SUB VARS VARIABLE SIZE
	272	STA SSIZ,1 SAVE TO STACK DEPTH
	273	*
	274	CRA
	275	STA FILL,1
	276	*
	277	LDA ATM1
	278	LDX XTM
	279	IRS INIT
	280	IRS INIT FOR FORTRAN COMPATIBILITY
	281	JMP* INIT
	282	*
	283	*
	284	********************************************************************************
	285	*
	286	*
	287	**** ERROR HANDLING ROUTINES
	288	*
	289	SUBR OFLO
	290	OFLO DAC ** STACK OVERFLOW ROUTINE
	291	LDA OMSP LOAD OVERFLOW MESSAGE POINTER
	292	JST TYPE TYPE IT OUT.
	293	*
	294	HLT WHAT WE DO: HALT THE MACHINE.
	295	JMP *-1 YOU CANNOT SIMPLY LEAVE THIS, IT'S SERIOUS!
	296	*
	297	*
	298	****************************************
	299	*
	300	*
	301	SUBR UFLO
	302	UFLO DAC ** STACK OVERFLOW ROUTINE
	303	LDA UMSP LOAD OVERFLOW MESSAGE POINTER
	304	JST TYPE TYPE IT OUT.
	305	*
	306	HLT WHAT WE DO: HALT THE MACHINE.
	307	JMP *-1 YOU CANNOT SIMPLY LEAVE THIS, IT'S SERIOUS!
	308	*
	309	*
	310	****************************************
	311	*
	312	*
	313	SUBR TYPE
	314	TYPE DAC **
	315	SKS '104 TEST ASR READY
	316	JMP *-1 WAIT TO BECOME READY
	317	OCP '104 SET TO OUTPUT MODE
	318	*
	319	STA PTR STORE POINTER
	320	*
	321	TLOP LDA* PTR TYPE LOOP
	322	SNZ TEST FOR END
	323	JMP* TYPE RETURN
	324	ICA
	325	OTA '4
	326	JMP *-1
	327	ICA
	328	OTA '4
	329	JMP *-1
	330	SKS '104 ADDITIONAL TEST FOR READY
	331	JMP *-1
	332	IRS PTR NEXT WORD.
	333	JMP TLOP
	334	*
	335	*
	336	********************************************************************************
	337	*
	338	*
	339	***** VARIABLES
	340	*
	341	*
	342	PTR DEC 0 TRANSFER POINTER TO USER BUFFERS
	343	CNT DEC 0 TRANSFER COUNTER
	344	*
	345	ATM1 DEC 0 A-REGISTER BACKUP
	346	ATM2 DEC 0 A-REGISTER BACKUP
	347	XTM DEC 0 X-REGISTER BACKUP
	348	*
	349	*
	350	***** CONSTANTS
	351	*
	352	VARS DEC 3 SIZE OF VARIABLES AT BEGINNING OF DATA
	353	*
	354	SSIZ EQU 0
	355	SPTR EQU 1
	356	FILL EQU 2
	357	*
	358	OMSP DAC OMSG POINTER TO MESSAGE
	359	UMSP DAC UMSG POINTER TO MESSAGE
	360	OMSG OCT '006412 CR/LF CHARACTERS
	361	BCI 16,STACK OVERFLOW, YOUR'RE SCREWED!
	362	DEC 0 TERMINATION CHARACTER
	363	UMSG OCT '006412 CR/LF CHARACTERS
	364	BCI 17,STACK UNDERFLOW, YOUR'RE SCREWED!
	365	DEC 0 TERMINATION CHARACTER
	366	*
	367	*
	368	********************************************************************************
	369	*
	370	*
	371	END THAT'S IT.