revers.s

;
; Ullrich von Bassewitz, 07.08.1998
;
; unsigned char revers (unsigned char onoff);
;

      	.export		_revers
	.export		revers

_revers:
	ldx    	#$00		; Assume revers off
	tay			; Test onoff
	beq	L1		; Jump if off
	ldx	#$80		; Load on value
L1:	ldy	#$00		; Assume old value is zero
	lda    	revers 	       	; Load old value
	stx	revers		; Set new value
	beq	L2		; Jump if old value zero
	iny			; Make old value = 1
L2:	ldx	#$00		; Load high byte of result
	tya			; Load low byte, set CC
	rts

.bss

revers:	.res	1

revers.s.html; generated on Sat Oct 13 22:41:33 2001 by ca65html
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