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cc65/libsrc/apple2/apple2-stdjoy.s
cuz 6af35e774d Rename the standard joystick driver for the Apple ][.
Rewrite the driver code to make it shorter.


git-svn-id: svn://svn.cc65.org/cc65/trunk@2117 b7a2c559-68d2-44c3-8de9-860c34a00d81
2003-05-02 11:53:21 +00:00

130 lines
3.2 KiB
ArmAsm

;
; Standard joystick driver for the Apple ][. May be used multiple times when
; linked to the statically application.
;
; Ullrich von Bassewitz, 2003-05-02
; Using the readjoy code from Stefan Haubenthal
;
.include "zeropage.inc"
.include "joy-kernel.inc"
.include "joy-error.inc"
.include "apple2.inc"
.macpack generic
; ------------------------------------------------------------------------
; Constants
OFFS = 10
; ------------------------------------------------------------------------
; Header. Includes jump table
.segment "JUMPTABLE"
; Driver signature
.byte $6A, $6F, $79 ; "joy"
.byte $00 ; Driver API version number
; Button state masks (8 values)
.byte $40
.byte $80
.byte $10
.byte $20
.byte $08
.byte $00 ; Future expansion
.byte $00 ; Future expansion
.byte $00 ; Future expansion
; Jump table.
.word INSTALL
.word UNINSTALL
.word COUNT
.word READJOY
; ------------------------------------------------------------------------
; 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 DEINSTALL 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.
;
READJOY:
and #$01 ; Fix joystick number
asl a ;
tax ; Joystick number (0,2) into X
; Read joystick
lda OPEN_APPLE,x ; Check fire button
and #$80 ; BTN 0 0 0 0 0 0 0
pha
jsr PREAD ; Read first paddle value
pla
cpy #127-OFFS
ror a ; /LEFT BTN 0 0 0 0 0 0
cpy #127+OFFS
ror a ; RIGHT /LEFT BTN 0 0 0 0 0
inx
pha
jsr PREAD ; Read second paddle
pla
cpy #127-OFFS
ror a ; /UP RIGHT /LEFT BTN 0 0 0 0
cpy #127+OFFS
ror a ; DOWN /UP RIGHT /LEFT BTN 0 0 0
eor #%01010000 ; DOWN UP RIGHT LEFT BTN 0 0 0
ldx #0 ; fix X
rts