mirror of
https://github.com/cc65/cc65.git
synced 2024-11-19 06:31:31 +00:00
42 lines
958 B
ArmAsm
42 lines
958 B
ArmAsm
;
|
|
; Karri Kaksonen, 2004-11-01
|
|
;
|
|
; char cgetc (void);
|
|
;
|
|
|
|
.export _cgetc
|
|
.import _kbhit
|
|
.import KBBUF
|
|
|
|
; --------------------------------------------------------------------------
|
|
; The Atari Lynx has a very small keyboard - only 3 keys
|
|
; Opt1, Opt2 and Pause.
|
|
; But the designers have decided that pressing Pause and Opt1 at the
|
|
; same time means Restart and pressing Pause and Opt2 means Flip screen.
|
|
|
|
; For "easter egg" use I have also included all three keys pressed '?'
|
|
; and Opt1 + Opt2 pressed '3'.
|
|
; So the keyboard returns '1', '2', '3', 'P', 'R', 'F' or '?'.
|
|
|
|
_cgetc:
|
|
jsr _kbhit ; Check for char available
|
|
tax ; Test result
|
|
beq _cgetc
|
|
|
|
ldx #5 ; Wait for some time... 0.2 seconds or so.
|
|
@L1: ldy #255
|
|
@L2: lda #255
|
|
@L3: dec
|
|
bne @L3
|
|
dey
|
|
bne @L2
|
|
dex
|
|
bne @L1
|
|
|
|
jsr _kbhit ; Check for double pressed buttons
|
|
lda KBBUF
|
|
stz KBBUF
|
|
ldx #0
|
|
rts
|
|
|