	.TITLE	CLRMEM


;	* * * ID-2000 SOFTWARE MODULE * * *


;	CLEARS CCD IMAGE REFRESH MEMORY OF ID-2000 SERIES
;	IMAGE DISPLAY SYSTEM.

;	ALL NEW CODE: 15 AUGUST 77
;	MODIFICATIONS TO: 12 APRIL 78

;	PROGRAMMER: KEN DINWIDDIE

	.MCALL	.REGDEF,.EXIT

	.REGDEF

	XREG	=166000
	BPMR	=166004
	CSR	=166006
	DREG	=166010
	.PAGE
	.SBTTL	ROUTINE TO CLEAR CCD MEMORY IN ID-2000 SERIES


CLRMEM:	MOV	#7777,@#BPMR	; ENABLE ALL BITS
	CLR	R0
	CLR	@#XREG		; START OF LINE BUFFER
ZEROLB:	MOV	R0,@#DREG	; FILL LINE BUFFER WITH ZEROES
	BIT	#1000,@#XREG
	BEQ	ZEROLB
	MOV	#15,@#CSR	; FILL ALL CCD MEMORY WITH ZEROES
WAIT:	TSTB	@#CSR
	BPL	WAIT		; WAIT FOR READY BIT APPEARANCE
	.EXIT
	.END	CLRMEM
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