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49 lines
553 B
ArmAsm
49 lines
553 B
ArmAsm
;
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; Ullrich von Bassewitz, 23.09.1998
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;
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; unsigned readjoy (unsigned char joy);
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;
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.export _readjoy
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.include "../inc/geossym.inc"
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.proc _readjoy
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php
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sei ; disable IRQ
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lda $01
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pha
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lda #$35
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sta $01 ; enable I/O
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tax ; Joystick number into X
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bne joy2
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; Read joystick 1
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joy1:
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lda #$7F
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sta cia1base
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lda cia1base+1
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back: tax
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pla
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sta $01
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plp
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txa
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and #$1F
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eor #$1F
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ldx #0
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rts
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; Read joystick 2
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joy2: lda #$E0
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ldy #$FF
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sta cia1base+2
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lda cia1base+1
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sty cia1base+2
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jmp back
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.endproc
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