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cc65/libsrc/cx16/joy/cx16-std.s

99 lines
2.7 KiB
ArmAsm

;
; Standard joystick driver for the CX16.
; May be installed multiple times when statically linked to an application.
;
; 2021-04-07, Greg King
;
.include "joy-kernel.inc"
.include "joy-error.inc"
.include "cbm_kernal.inc"
.include "cx16.inc"
.macpack generic
.macpack module
.importzp tmp1
; ------------------------------------------------------------------------
; Header. Includes jump table
module_header _cx16_std_joy
; Driver signature
.byte $6A, $6F, $79 ; ASCII "joy"
.byte JOY_API_VERSION ; Driver API version number
; Library reference
.addr $0000
; Jump table.
.addr INSTALL
.addr UNINSTALL
.addr COUNT
.addr READ
; ------------------------------------------------------------------------
; Constant
JOY_COUNT = $05 ; 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.
; Must return a JOY_ERR_xx code in .XA .
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 clean-up or whatever. Shouldn't return anything.
UNINSTALL:
rts
; ------------------------------------------------------------------------
; COUNT: Return the total number of possible joysticks, in .XA .
COUNT: lda #<JOY_COUNT
ldx #>JOY_COUNT
rts
; ------------------------------------------------------------------------
; READ: Read a particular joystick passed in .A .
READ: cmp #JOY_COUNT
blt :+
lda #$00
: jsr JOYSTICK_GET
sta tmp1
txa
bit #%00001110 ; Is it NES or SNES controller?
bze nes
asl tmp1 ; Get SNES's B button
ror a ; Put it next to the A button
asl tmp1 ; Drop SNES's Y button
asl a ; Get back the B button
ror tmp1
asl a ; Get SNES's A button
ror tmp1 ; Make byte look like NES pad
nes: lda tmp1 ; The controllers give zeroes for "pressed"
eor #%11111111 ; We want ones for "pressed"
rts