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cc65/libsrc/c64/joy/c64-hitjoy.s
Oliver Schmidt 2c975d3642 Create static drivers directly from source files.
Up to now static drivers were created via co65 from dynamic drivers. However there was an issue with that approach:

The dynamic drivers are "o65 simple files" which obligates that they start with the 'code' segment. However dynamic drivers need to start with the module header - which is written to. For dynamic drivers this isn't more than a conceptual issue because they are always contain a 'data' segment and may therefore only be loaded into writable memory.

However when dynamic drivers are converted to static drivers using co65 then that issue becomes a real problem as then the 'code' segment may end up in non-writable memory - and thus writing to the module header fails.

Instead of changing the way dynamic drivers work I opted to rather make static driver creation totally independent from dynamic drivers. This allows to place the module header in the 'data' segment (see 'module.mac').
2014-06-04 23:50:18 +02:00

230 lines
5.8 KiB
ArmAsm

;
; 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
.macpack module
; ------------------------------------------------------------------------
; Header. Includes jump table
module_header _c64_hitjoy_joy
; Driver signature
.byte $6A, $6F, $79 ; "joy"
.byte JOY_API_VERSION ; Driver API version number
; Library reference
.addr $0000
; 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