2 ; Ullrich von Bassewitz, 07.08.1998
4 ; unsigned char revers (unsigned char onoff);
11 ldx #$00 ; Assume revers off
14 ldx #$80 ; Load on value
15 L1: ldy #$00 ; Assume old value is zero
16 lda revers ; Load old value
17 stx revers ; Set new value
18 beq L2 ; Jump if old value zero
19 iny ; Make old value = 1
20 L2: ldx #$00 ; Load high byte of result
21 tya ; Load low byte, set CC