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cc65/libsrc/c64/c64-hitjoy.s
cuz cbdcab4fdb Change the sematics of callirq and the existing interruptors: The interrupts
must now return carry set if the interrupt has been handled, and carry clear
if not. The callirq routine will stop calling handlers with the first handler
that claims to have handled the interrupt. callirq will return the carry flag
to the caller as it came from the last interruptor called.


git-svn-id: svn://svn.cc65.org/cc65/trunk@3491 b7a2c559-68d2-44c3-8de9-860c34a00d81
2005-04-25 20:10:10 +00:00

224 lines
5.6 KiB
ArmAsm
Executable File

;
; DXS/HIT-4 Player joystick driver for the C64
;
; Groepaz/Hitmen, 2002-12-23
; obviously based on Ullrichs driver :)
;
.include "zeropage.inc"
.include "joy-kernel.inc"
.include "joy-error.inc"
.include "c64.inc"
.macpack generic
; ------------------------------------------------------------------------
; Header. Includes jump table
.segment "JUMPTABLE"
; Driver signature
.byte $6A, $6F, $79 ; "joy"
.byte JOY_API_VERSION ; Driver API version number
; Button state masks (8 values)
.byte $01 ; JOY_UP
.byte $02 ; JOY_DOWN
.byte $04 ; JOY_LEFT
.byte $08 ; JOY_RIGHT
.byte $10 ; JOY_FIRE
.byte $00 ; JOY_FIRE2 unavailable
.byte $00 ; Future expansion
.byte $00 ; Future expansion
; Jump table.
.addr INSTALL
.addr UNINSTALL
.addr COUNT
.addr READ
.addr IRQ
; ------------------------------------------------------------------------
; Constants
JOY_COUNT = 4 ; Number of joysticks we support
; ------------------------------------------------------------------------
; Data. Written in the IRQ, read by the READ routine
.bss
temp3: .byte 0
temp4: .byte 0
.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 UNINSTALL instead
; ------------------------------------------------------------------------
; UNINSTALL routine. Is called before the driver is removed from memory.
; Can do cleanup or whatever. Must not return anything.
;
UNINSTALL:
rts
; ------------------------------------------------------------------------
; IRQ entry point. Is called from the C layer as a subroutine in the
; interrupt. The routine MUST return carry set if the interrupt has been
; 'handled' - which means that the interrupt source is gone. Otherwise it
; MUST return carry clear.
IRQ: ; cia 2 setup
ldy #$00 ; port b direction
sty $dd03 ; => input
sty $dd05 ; cia2 timer a highbyte
sty $dc05 ; cia1 timer a highbyte
iny
sty $dd04 ; cia2 timer a lowbyte
sty $dc04 ; cia1 timer a lowbyte
lda #%00010001
sta $dd0e ; control register a
; timer: start
; continous
; forced load
; serial port: input
; cia 1 setup
lda #%01010001
sta $dc0e ; control register a
; timer: start
; continous
; forced load
; serial port: output
; read directions 3
lda $dd01 ;read cia 2 port b
and #$0f
sta temp3
; read button 3
lda $dd02 ;cia 2 port a
and #%11111011 ;data direction
sta $dd02 ;=> bit 2 input
lda $dd00 ;read cia 2 p.A
and #%00000100 ;check bit 2
asl a
asl a
ora temp3
sta temp3
; read directions 4
lda $dd01 ;read cia 2 port b
lsr a
lsr a
lsr a
lsr a
sta temp4
; read button 4
ldx #$ff ;serial data register
stx $dc0c ;=> writing $ff causes
;cia to output some
;count signals at cnt1
ldx $dd0c ;read cia 2 serial in
beq fire ;button press if zero
lda temp4
ora #%00010000
sta temp4
fire:
; Default Value: $40/64 on PAL
; $42/66 on NTSC
lda #$41
sta $dc05
; Default Value: $25/37 on PAL
; $95/149 on NTSC
lda #0
sta $dc04
; We do never "handle" the interrupt, we use it just as a timer.
clc
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.
;
READ: tax ; Joystick number into X
bne joy2
; Read joystick 1
joy1: lda #$7F
sei
sta CIA1_PRA
lda CIA1_PRB
cli
and #$1F
eor #$1F
rts
; Read joystick 2
joy2: dex
bne joy3
; ldx #0
lda #$E0
ldy #$FF
sei
sta CIA1_DDRA
lda CIA1_PRA
sty CIA1_DDRA
cli
and #$1F
eor #$1F
rts
; Read joystick 3
joy3: dex
bne joy4
lda temp3
eor #$1F
rts
; Read joystick 4
joy4: lda temp4
eor #$1F
ldx #0
rts