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cc65/libsrc/c64/joy/c64-numpad.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

154 lines
4.3 KiB
ArmAsm

;
; Joystick driver using C128 number pad in 64 mode.
; May be used multiple times when linked to the statically application.
;
; Stefan Haubenthal, 2004-01-26
; Based on Ullrich von Bassewitz, 2002-12-20
;
.include "zeropage.inc"
.include "joy-kernel.inc"
.include "joy-error.inc"
.include "c64.inc"
.macpack generic
.macpack module
; ------------------------------------------------------------------------
; Header. Includes jump table
module_header _c64_numpad_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 = 1 ; Number of joysticks we support
; ------------------------------------------------------------------------
; Data.
.rodata
; <U>p '8' key
; <D>own '2' key
; <L>eft '4' key
; <R>ight '6' key
; <B>utton '5' or ENTER key
masktable:
; Input: LDRBU
; Output: BRLDU
.byte %00000000 ; $00
.byte %00000001 ; $01
.byte %00010000 ; $02
.byte %00010001 ; $03
.byte %00001000 ; $04
.byte %00001001 ; $05
.byte %00011000 ; $06
.byte %00011001 ; $07
.byte %00000010 ; $08
.byte %00000011 ; $09
.byte %00010010 ; $0A
.byte %00010011 ; $0B
.byte %00001010 ; $0C
.byte %00001011 ; $0D
.byte %00011010 ; $0E
.byte %00011011 ; $0F
.byte %00000100 ; $10
.byte %00000101 ; $11
.byte %00010100 ; $12
.byte %00010101 ; $13
.byte %00001100 ; $14
.byte %00001101 ; $15
.byte %00011100 ; $16
.byte %00011101 ; $17
.byte %00000110 ; $18
.byte %00000111 ; $19
.byte %00010110 ; $1A
.byte %00010111 ; $1B
.byte %00001110 ; $1C
.byte %00001111 ; $1D
.byte %00011110 ; $1E
.byte %00011111 ; $1F
.code
; ------------------------------------------------------------------------
; INSTALL routine. Is called after the driver is loaded into memory. If
; possible, check if the hardware is present and determine the amount of
; memory available.
; Must return an JOY_ERR_xx code in a/x.
;
INSTALL:
lda #JOY_ERR_OK ; Assume we have a joystick
ldx VIC_CLK_128 ; Test for a C128
cpx #$FF
bne @C128 ; Jump if we have one
lda #JOY_ERR_NO_DEVICE ; No C128 -> no numpad
@C128: ldx #0 ; Set high byte
; 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 #0
rts
; ------------------------------------------------------------------------
; READ: Read a particular joystick passed in A.
;
READ: tax ; Clear high byte
lda #$FD ; For ENTER and '6'
ldy #$FE ; For '8', '5', '2', '4'
sei
sta VIC_KBD_128
lda CIA1_PRB
and #%00110000
eor #%00110000
lsr ; Map ENTER ...
lsr ; ... onto '5'
sty VIC_KBD_128
eor CIA1_PRB
iny
sty VIC_KBD_128 ; Reset to $FF
cli
and #%00111110
eor #%00111110
lsr
tay
lda masktable,y ; Convert LDRBU to BRLDU
rts