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cc65/libsrc/c16/revers.s
uz 5c5d01d84a Moved most platform assembler includes into asminc, so they will be available
in the distribution. 
Added --forget-inc-paths to the command line of the assembler in the
Makefiles, because the assembler does now have builtin paths and will find
include files from an installation first.
Hopefully fixed any problems that arose from the two changes.


git-svn-id: svn://svn.cc65.org/cc65/trunk@4223 b7a2c559-68d2-44c3-8de9-860c34a00d81
2009-09-24 17:44:22 +00:00

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554 B
ArmAsm

;
; Ullrich von Bassewitz, 07.08.1998
;
; unsigned char revers (unsigned char onoff);
;
.export _revers
.include "plus4.inc"
.proc _revers
ldx #$00 ; Assume revers off
tay ; Test onoff
beq L1 ; Jump if off
ldx #$80 ; Load on value
ldy #$00 ; Assume old value is zero
L1: lda RVS ; Load old value
stx RVS ; 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
.endproc