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cc65/libsrc/atmos/kbhit.s

19 lines
420 B
ArmAsm

;
; Ullrich von Bassewitz, 2003-04-13
;
; int kbhit (void);
;
.export _kbhit
.include "atmos.inc"
_kbhit:
ldx #$00 ; Load high byte
lda KEYBUF ; Flag for new char in bit 7
asl a ; Shift bit 7 into carry
txa ; A = 0
rol a ; Move old bit 7 into bit 0
rts