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cc65/libsrc/atmos/joy/atmos-pase.s

127 lines
3.1 KiB
ArmAsm

;
; P.A.S.E. joystick driver for the Atmos
; Can be used multiple times when statically linked to the application.
;
; 2002-12-20, Based on Ullrich von Bassewitz's code.
; 2009-12-21, Stefan Haubenthal
; 2013-07-15, Greg King
;
.include "joy-kernel.inc"
.include "joy-error.inc"
.include "atmos.inc"
; ------------------------------------------------------------------------
; Header. Includes jump table
.segment "JUMPTABLE"
; Driver signature
.byte $6A, $6F, $79 ; "joy"
.byte JOY_API_VERSION ; Driver API version number
; Library reference
.addr $0000
; Button state masks (8 values)
.byte $10 ; JOY_UP
.byte $08 ; JOY_DOWN
.byte $01 ; JOY_LEFT
.byte $02 ; JOY_RIGHT
.byte $20 ; JOY_FIRE
.byte $00 ; Future expansion
.byte $00 ; Future expansion
.byte $00 ; Future expansion
; Jump table.
.addr INSTALL
.addr UNINSTALL
.addr COUNT
.addr READ
.addr 0 ; IRQ entry unused
; ------------------------------------------------------------------------
; Constants
JOY_COUNT = 2 ; Number of joysticks we support
; ------------------------------------------------------------------------
; Data.
.bss
temp1: .byte $00
temp2: .byte $00
.code
; ------------------------------------------------------------------------
; INSTALL routine. Is called after the driver is loaded into memory. If
; possible, check if the hardware is present and determine the amount of
; memory available.
; Must return an JOY_ERR_xx code in a/x.
;
INSTALL:
lda #JOY_ERR_OK
ldx #0
; rts ; Run into UNINSTALL instead
; ------------------------------------------------------------------------
; UNINSTALL routine. Is called before the driver is removed from memory.
; Can do cleanup or whatever. Must not return anything.
;
UNINSTALL:
rts
; ------------------------------------------------------------------------
; COUNT: Return the total number of available joysticks in a/x.
;
COUNT:
lda #JOY_COUNT
ldx #0
rts
; ------------------------------------------------------------------------
; READ: Read a particular joystick passed in A.
;
READ:
tay
lda VIA::PRA
pha
lda VIA::DDRA
pha
lda #%11000000
sta VIA::DDRA
lda #%10000000
sta VIA::PRA2
lda VIA::PRA2
sta temp1
lda #%01000000
sta VIA::PRA2
lda VIA::PRA
sta temp2
pla
sta VIA::DDRA
pla
sta VIA::PRA2
ldx #0
tya
bne @L1
lda temp1
eor #$FF
rts
@L1: lda temp2
eor #$FF
rts