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cc65/libsrc/atari/joy/atrstd.s
Oliver Schmidt 1976d6cd32 Removed IRQ support from joystick drivers.
All but one joystick drivers didn't use IRQs. Espsecially when the joystick driver kernel was the only .interruptor this meant quite some unnecessary overhead because it pulled in the whole IRQ infrastructure.

I was told that the one driver using IRQs (the DXS/HIT-4 Player joystick driver for the C64) can be reworked to not do it. Until this is done that driver is defunct.
2018-02-01 22:38:36 +01:00

110 lines
2.6 KiB
ArmAsm

;
; Standard joystick driver for the Atari. May be used multiple times when linked
; to the statically application.
;
; Ullrich von Bassewitz, 2002-12-21
; Using the readjoy code from Christian Groessler
;
.include "zeropage.inc"
.include "joy-kernel.inc"
.include "joy-error.inc"
.include "atari.inc"
.macpack generic
.macpack module
; ------------------------------------------------------------------------
; Header. Includes jump table
.ifdef __ATARIXL__
module_header _atrxstd_joy
.else
module_header _atrstd_joy
.endif
; 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 READJOY
; ------------------------------------------------------------------------
; Constants
JOY_COUNT = 4 ; 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 #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 $fcd8
cpx #$a2
beq _400800
lsr a ; XL and newer machines only have 2 ports
_400800:
ldx #0
rts
; ------------------------------------------------------------------------
; READ: Read a particular joystick passed in A.
;
READJOY:
and #3 ; fix joystick number
tax ; Joystick number (0-3) into X
; Read joystick
lda STRIG0,x ; get button
asl a
asl a
asl a
asl a
ora STICK0,x ; add position information
eor #$1F
ldx #0 ; fix X
rts