mirror of https://github.com/cc65/cc65.git
163 lines
4.1 KiB
ArmAsm
163 lines
4.1 KiB
ArmAsm
;
|
|
; Standard joystick driver for the Atari 7800.
|
|
; This version tries to use 7800 and 2600 joysticks.
|
|
; But assumes that both joysticks are of same type.
|
|
;
|
|
; Modified by Karri Kaksonen, 2022-03-31
|
|
; Ullrich von Bassewitz, 2002-12-20
|
|
; Using code from Steve Schmidtke
|
|
;
|
|
|
|
.include "zeropage.inc"
|
|
|
|
.include "joy-kernel.inc"
|
|
.include "joy-error.inc"
|
|
.include "atari7800.inc"
|
|
|
|
.macpack generic
|
|
.macpack module
|
|
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Header. Includes jump table
|
|
|
|
module_header _atari7800_stdjoy_joy
|
|
|
|
; Driver signature
|
|
|
|
.byte $6A, $6F, $79 ; "joy"
|
|
.byte JOY_API_VERSION ; Driver API version number
|
|
|
|
; Library reference
|
|
|
|
.addr $0000
|
|
|
|
; Jump table.
|
|
|
|
.addr INSTALL
|
|
.addr UNINSTALL
|
|
.addr COUNT
|
|
.addr READ
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Constants
|
|
|
|
JOY_COUNT = 2 ; Number of joysticks we support
|
|
|
|
.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:
|
|
; Assume 7800 2-button controller, can change
|
|
; to 2600 1-button later
|
|
lda #$14
|
|
sta CTLSWB ; enable 2-button 7800 controller 1: set pin 6 to output
|
|
ldy #$00
|
|
sty SWCHB ; enable 2-button 7800 controller 2: pull pin 6 (INPT4) high
|
|
|
|
reset:
|
|
lda #JOY_ERR_OK
|
|
.assert JOY_ERR_OK = 0, error
|
|
tax
|
|
; 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 for 2 fire buttons.
|
|
|
|
readbuttons:
|
|
; Y has joystick of interest 0/1
|
|
; return value:
|
|
; $00: no button,
|
|
; $01: left/B button,
|
|
; $02: right/A button,
|
|
; $03: both buttons
|
|
; preserves X
|
|
tya
|
|
beq L5
|
|
; Joystick 1 processing
|
|
; 7800 joystick 1 buttons
|
|
ldy #0 ; ........
|
|
bit INPT2 ; Check for right button
|
|
bpl L1
|
|
ldy #2 ; ......2.
|
|
L1: bit INPT3 ;Check for left button
|
|
bpl L2
|
|
iny ; ......21
|
|
L2: tya
|
|
bne L4 ; 7800 mode joystick worked
|
|
; 2600 Joystick 1
|
|
bit INPT5
|
|
bmi L4
|
|
L3: iny ; .......1
|
|
lda #0 ; Fallback to 2600 joystick mode
|
|
sta CTLSWB
|
|
L4: tya ; ......21
|
|
rts
|
|
|
|
L5: ; Joystick 0 processing
|
|
; 7800 joystick 0 buttons
|
|
ldy #0 ; ........
|
|
bit INPT0 ; Check for right button
|
|
bpl L6
|
|
ldy #2 ; ......2.
|
|
L6: bit INPT1 ;Check for left button
|
|
bpl L7
|
|
iny ; ......21
|
|
L7: tya
|
|
bne L4 ; 7800 mode joystick worked
|
|
; 2600 Joystick 0
|
|
bit INPT4
|
|
bmi L4
|
|
bpl L3
|
|
|
|
READ:
|
|
tay ; Store joystick 0/1 in Y
|
|
beq L8
|
|
lda SWCHA ; Read directions of joystick 1
|
|
rol ; ...RLDU.
|
|
rol ; ..RLDU..
|
|
rol ; .RLDU... - joystick 1
|
|
jmp L9
|
|
L8: lda SWCHA ; Read directions of joystick 0
|
|
ror ; .RLDU... - joystick 0
|
|
L9: tax
|
|
jsr readbuttons ; A = ......21, X = .RLDU...
|
|
ror ; A = .......2 1
|
|
tay ; Y = .......2
|
|
txa ; A = .RLDU...
|
|
ror ; A = 1.RLDU..
|
|
tax ; X = 1.RLDU..
|
|
tya ; A = .......2
|
|
ror ; A = ........ 2
|
|
txa ; A = 1.RLDU..
|
|
rol ; A = .RLDU..2 1
|
|
rol ; A = RLDU..21
|
|
eor #$F0 ; The direction buttons were inversed
|
|
and #$F3
|
|
rts
|
|
|