; EBCASC.MAC    6-JUL-78
;
	.TITLE	EBCASC
	.IDENT	/V01/
;
;	*	*	*	*	*	*	*	*	*
;
; EBCASC - TRANSLATE FROM EBCDIC TO ASCII
; 
;	THIS IS ONE OF A SET OF BYTE MANIPULATION ROUTINES IN WHICH THE
; BEGINNING OF A STRING IS SPECIFIED BY AN ADDRESS,COUNT PAIR A,K WHERE
; A IS A BASE ADDRESS (OF A VARIABLE OR ARRAY) AND K IS A TWO-BYTE
; INTEGER WORD SPECIFYING AT WHICH BYTE OF A THE STRING BEGINS.  K MAY BE
; POSITIVE, ZERO, OR NEGATIVE.  K=1 MEANS THE FIRST BYTE OF A.
;  
; CALL EBCASC(A1,K1,A2,K2,L)
;  
;	THIS ROUTINE MOVES L BYTES FROM A1,K1 TO A2,K2, CONVERTING EACH
; BYTE FROM EBCDIC TO ASCII.
;  
;	A1,K1 - SPECIFIES THE BEGINNING OF THE SOURCE STRING.  A1 MAY BE
;		A LITERAL CONSTANT.
;	A2,K2 - SPECIFIES THE BEGINNING OF THE DESTINATION STRING.
;	L - A TWO-BYTE INTEGER COUNT OF THE NUMBER OF BYTES TO MOVE.
;		IF L IS ZERO OR NEGATIVE, NO BYTES ARE MOVED.
;  
;
;	IF THE SOURCE AND DESTINATION STRINGS ARE THE SAME, THEN THE
; CONVERSION IS DONE IN PLACE.
;
;	THIS ROUTINE DOES NOTHING IF PASSED THE WRONG NUMBER OF ARGUMENTS.
;
;	THIS ROUTINE USES THE SAME EBCDIC/ASCII TRANSLATION PERFORMED BY
; THE IBM 360 OPERATING SYSTEM.
;  
;	*	*	*	*	*	*	*	*	*
;
;  
;
;
;
;	WRITTEN BY BOB TURKELSON, NASA/GSFC CODE 626
;
;
	.EVEN
;        TABLE FOR TRANSLATING FROM EBCDIC TO ASCII                             
TABLE:
	.BYTE	  0,  1,  2,  3, 32, 11, 32,177	; 000102031A091A7F
	.BYTE	 32, 32, 32, 13, 14, 15, 16, 17	; 1A1A1A0B0C0D0E0F
	.BYTE	 20, 21, 22, 23, 32, 32, 10, 32	; 101112131A1A081A
	.BYTE	 30, 31, 32, 32, 34, 35, 36, 37	; 18191A1A1C1D1E1F
	.BYTE	 32, 32, 32, 32, 32, 12, 27, 33	; 1A1A1A1A1A0A171B
	.BYTE	 32, 32, 32, 32, 32,  5,  6,  7	; 1A1A1A1A1A050607
	.BYTE	 32, 32, 26, 32, 32, 32, 32,  4	; 1A1A161A1A1A1A04
	.BYTE	 32, 32, 32, 32, 24, 25, 32, 32	; 1A1A1A1A14151A1A
	.BYTE	 40, 32, 32, 32, 32, 32, 32, 32	; 201A1A1A1A1A1A1A
	.BYTE	 32, 32,133, 56, 74, 50, 53, 41	; 1A1A5B2E3C282B21
	.BYTE	 46, 32, 32, 32, 32, 32, 32, 32	; 261A1A1A1A1A1A1A
	.BYTE	 32, 32,135, 44, 52, 51, 73,136	; 1A1A5D242A293B5E
	.BYTE	 55, 57, 32, 32, 32, 32, 32, 32	; 2D2F1A1A1A1A1A1A
	.BYTE	 32, 32,174, 54, 45,137, 76, 77	; 1A1A7C2C255F3E3F
	.BYTE	 32, 32, 32, 32, 32, 32, 32, 32	; 1A1A1A1A1A1A1A1A
	.BYTE	 32,140, 72, 43,100, 47, 75, 42	; 1A603A2340273D22
	.BYTE	 32,141,142,143,144,145,146,147	; 1A61626364656667
	.BYTE	150,151, 32, 32, 32, 32, 32, 32	; 68691A1A1A1A1A1A
	.BYTE	 32,152,153,154,155,156,157,160	; 1A6A6B6C6D6E6F70
	.BYTE	161,162, 32, 32, 32, 32, 32, 32	; 71721A1A1A1A1A1A
	.BYTE	 32,176,163,164,165,166,167,170	; 1A7E737475767778
	.BYTE	171,172, 32, 32, 32, 32, 32, 32	; 797A1A1A1A1A1A1A
	.BYTE	 32, 32, 32, 32, 32, 32, 32, 32	; 1A1A1A1A1A1A1A1A
	.BYTE	 32, 32, 32, 32, 32, 32, 32, 32	; 1A1A1A1A1A1A1A1A
	.BYTE	173,101,102,103,104,105,106,107	; 7B41424344454647
	.BYTE	110,111, 32, 32, 32, 32, 32, 32	; 48491A1A1A1A1A1A
	.BYTE	175,112,113,114,115,116,117,120	; 7D4A4B4C4D4E4F50
	.BYTE	121,122, 32, 32, 32, 32, 32, 32	; 51521A1A1A1A1A1A
	.BYTE	134, 32,123,124,125,126,127,130	; 5C1A535455565758
	.BYTE	131,132, 32, 32, 32, 32, 32, 32	; 595A1A1A1A1A1A1A
	.BYTE	 60, 61, 62, 63, 64, 65, 66, 67	; 3031323334353637
	.BYTE	 70, 71, 32, 32, 32, 32, 32, 32	; 38391A1A1A1A1A1A
EBCASC::
 	CMPB	#5,(R5)		; ARE 5 ARGUMENTS PASSED?
	BNE	RTR		; IF NE NO
	MOV	@12(R5),R0	; GET NO. OF BYTES TO PROCESS (ARG 5)
	BLE	RTR		; IF LE ZERO RETURN
	TST 	(R5)+		; ADVANCE POINTER TO ARGUMENT 1
	MOV	(R5)+,R1	; GET BASE ADDRESS OF SOURCE (ARG 1)
	ADD	@(R5)+,R1	; ADD SOURCE BYTE NUMBER (ARG 2)
	DEC	R1		; SUBTRACT 1 FOR ADDRESS OF 1ST SOURCE BYTE
	MOV	(R5)+,R2	; GET BASE ADDRESS OF DESTINATION (ARG 3)
	ADD	@(R5)+,R2	; ADD DESTINATION BYTE NUMBER (ARG 4)
	DEC	R2		; SUBTRACT 1 FOR ADDR OF 1ST DESTINATION BYTE
;
;
	MOV	#TABLE,R4	; GET ADDRESS OF TRANSLATION TABLE
RPT:	MOVB	(R1)+,R3	; GET NEXT SOURCE BYTE
	BIC	#177400,R3	; CLEAR UPPER BYTE OF REGISTER
	ADD	R4,R3		; CALC ADDR IN TABLE OF TRANSLATED CHAR
	MOVB	(R3),(R2)+	; MOVE TRANSLATED CHAR TO DESTINATION
	SOB	R0,RPT		; REPEAT IF MORE BYTES TO PROCESS
;
RTR:	RTS	PC		; DONE
	.END