mirror of
https://github.com/cc65/cc65.git
synced 2024-12-27 15:29:46 +00:00
142 lines
3.4 KiB
ArmAsm
142 lines
3.4 KiB
ArmAsm
;
|
|
; Standard joystick driver for the Commodore 510 (aka P500). May be used
|
|
; multiple times when linked to the statically application.
|
|
;
|
|
; Ullrich von Bassewitz, 2003-02-16
|
|
;
|
|
|
|
.include "zeropage.inc"
|
|
.include "extzp.inc"
|
|
|
|
.include "joy-kernel.inc"
|
|
.include "joy-error.inc"
|
|
.include "cbm510.inc"
|
|
.include "extzp.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 $01 ; JOY_UP
|
|
.byte $02 ; JOY_DOWN
|
|
.byte $04 ; JOY_LEFT
|
|
.byte $08 ; 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 = 2 ; 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.
|
|
;
|
|
|
|
READ: ldx #$0F ; Switch to the system bank
|
|
stx IndReg
|
|
tax ; Save joystick number
|
|
|
|
; Get the direction bits
|
|
|
|
ldy #CIA::PRB
|
|
lda (cia2),y ; Read joystick inputs
|
|
sta tmp1
|
|
|
|
; Get the fire bits
|
|
|
|
ldy #CIA::PRA
|
|
lda (cia2),y
|
|
|
|
; Make the result value
|
|
|
|
cpx #$00 ; Joystick 0?
|
|
bne @L1 ; Jump if no
|
|
|
|
; Joystick 1, fire is in bit 6, direction in bit 0-3
|
|
|
|
asl a
|
|
jmp @L2
|
|
|
|
; Joystick 2, fire is in bit 7, direction in bit 5-7
|
|
|
|
@L1: ldx #$00 ; High byte of return value
|
|
lsr tmp1
|
|
lsr tmp1
|
|
lsr tmp1
|
|
lsr tmp1
|
|
|
|
; Mask the relavant bits, get the fire bit
|
|
|
|
@L2: asl a ; Fire bit into carry
|
|
lda tmp1
|
|
and #$0F
|
|
bcc @L3
|
|
ora #$10
|
|
@L3: eor #$1F ; All bits are inverted
|
|
|
|
; Switch back to the execution bank and return the joystick mask in a/x
|
|
|
|
ldy ExecReg
|
|
sty IndReg
|
|
rts
|
|
|