.TITLE	HTXT SFGL70 ROUTINE TO PLOT HORIZONTAL TEXT

.IDENT	'HTXT00'

.PSECT	HTXT

;	KEN DEMERS
;	UTRC
;	1970

;	THIS ROUTINE IS PART OF THE PDP-11/70 SMALL
;	FAST GRAPHICS LIBRARY (SFGL70). IT PLOTS
;	CHARACTERS ON THE SCREEN HORIZONTALLY,
;	STARTING FROM THE PRESENT CURSOR POSITION.
;	THE STRING IS ASSUMED TO BE TERMINATED BY
;	A ZERO BYTE.

;	CALLING FORMAT:

;	CALL HTXT(IBUFF)

;	IBUFF	= BUFFER CONTAINING THE ASCII CHARACTERS

;	INTERNAL GLOBALS

.GLOBL	H$TXT

;	EXTERNAL GLOBALS

.GLOBL	C$HAR,ALPHA,S$AVARG,R$STARG



H$TXT:	CALL	S$AVARG		;SAVE REGS
	CALL	ALPHA		;PUT SCOPE IN ALPHA MODE
	MOV	#IBFPTR,R2	;R2= C$HAR ARG BLK IBUFF PTR LOC
	MOV	2(R5),(R2)	;INIT IBFPTR
	MOV	#ARGBLK,R5	;R5= A(C$HAR ARG BLK)
HTX10:	TSTB	@(R2)		;END OF STRING?
	BEQ	HTX20		;YES
	CALL	C$HAR		;PRINT 1 C$HAR
	INC	(R2)		;BUMP STRING PTR
	BR	HTX10		;PRINT NEXT C$HAR
HTX20:	CALL	R$STARG		;RESTORE REGS
	RETURN

ARGBLK:	.BYTE	1,0		;1 ARG,NOT USED
IBFPTR:	.WORD	0		;PTR TO IBUF ADDR
	.END