mirror of
https://github.com/cc65/cc65.git
synced 2024-11-04 17:04:58 +00:00
117 lines
3.5 KiB
ArmAsm
117 lines
3.5 KiB
ArmAsm
;
|
|
; Standard joystick driver for the VIC20. May be used multiple times when linked
|
|
; to the statically application.
|
|
;
|
|
; Ullrich von Bassewitz, 2002-12-20
|
|
; Using code from Steve Schmidtke
|
|
;
|
|
|
|
.include "zeropage.inc"
|
|
|
|
.include "joy-kernel.inc"
|
|
.include "joy-error.inc"
|
|
.include "vic20.inc"
|
|
|
|
.macpack generic
|
|
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Header. Includes jump table
|
|
|
|
.segment "JUMPTABLE"
|
|
|
|
; Driver signature
|
|
|
|
.byte $6A, $6F, $79 ; "joy"
|
|
.byte JOY_API_VERSION ; Driver API version number
|
|
|
|
; Button state masks (8 values)
|
|
|
|
.byte $02 ; JOY_UP
|
|
.byte $04 ; JOY_DOWN
|
|
.byte $08 ; JOY_LEFT
|
|
.byte $80 ; JOY_RIGHT
|
|
.byte $10 ; JOY_FIRE
|
|
.byte $00 ; JOY_FIRE2 unavailable
|
|
.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 = 1 ; Number of joysticks we support
|
|
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Data.
|
|
|
|
|
|
.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 #>JOY_ERR_OK
|
|
; 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 #>JOY_COUNT
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; READ: Read a particular joystick passed in A.
|
|
; The current implemenation will ignore the joystick number because we do only
|
|
; have one joystick
|
|
|
|
READ: lda #$7F ; mask for VIA2 JOYBIT: sw3
|
|
ldx #$C3 ; mask for VIA1 JOYBITS: sw0,sw1,sw2,sw4
|
|
sei ; necessary?
|
|
|
|
ldy VIA2_DDRB ; remember the date of DDRB
|
|
sta VIA2_DDRB ; set JOYBITS on this VIA for input
|
|
lda VIA2_JOY ; read JOYBIT: sw3
|
|
sty VIA2_DDRB ; restore the state of DDRB
|
|
asl ; Shift sw3 into carry
|
|
|
|
ldy VIA1_DDRA ; remember the state of DDRA
|
|
stx VIA1_DDRA ; set JOYBITS on this VIA for input
|
|
lda VIA1_JOY ; read JOYBITS: sw0,sw1,sw2,sw4
|
|
sty VIA1_DDRA ; restore the state of DDRA
|
|
|
|
cli ; necessary?
|
|
ror ; Shift sw3 into bit 7
|
|
and #$9E ; Mask relevant bits
|
|
eor #$9E ; Active states are inverted
|
|
|
|
rts
|
|
|
|
|