; Using code from Steve Schmidtke
;
- .include "zeropage.inc"
+ .include "zeropage.inc"
- .include "joy-kernel.inc"
- .include "joy-error.inc"
- .include "vic20.inc"
+ .include "joy-kernel.inc"
+ .include "joy-error.inc"
+ .include "vic20.inc"
; ------------------------------------------------------------------------
; Header. Includes jump table
- .segment "JUMPTABLE"
+ .segment "JUMPTABLE"
; Driver signature
- .byte $6A, $6F, $79 ; "joy"
- .byte JOY_API_VERSION ; Driver API version number
+ .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
+ .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 0 ; IRQ entry unused
+ .addr INSTALL
+ .addr UNINSTALL
+ .addr COUNT
+ .addr READ
+ .addr 0 ; IRQ entry unused
; ------------------------------------------------------------------------
; Constants
-VIA1_PRB := VIA1 ; User port register
-JOY_COUNT = 3 ; Number of joysticks we support
+VIA1_PRB := VIA1 ; User port register
+JOY_COUNT = 3 ; Number of joysticks we support
.code
;
INSTALL:
- lda #<JOY_ERR_OK
- ldx #>JOY_ERR_OK
-; rts ; Run into UNINSTALL instead
+ lda #<JOY_ERR_OK
+ ldx #>JOY_ERR_OK
+; rts ; Run into UNINSTALL instead
; ------------------------------------------------------------------------
; UNINSTALL routine. Is called before the driver is removed from memory.
;
UNINSTALL:
- rts
+ rts
; ------------------------------------------------------------------------
;
COUNT:
- lda #<JOY_COUNT
- ldx #>JOY_COUNT
- rts
+ lda #<JOY_COUNT
+ ldx #>JOY_COUNT
+ rts
; ------------------------------------------------------------------------
; READ: Read a particular joystick passed in A.
;
-READ: tax ; Joystick number into X
- bne joy2
+READ: tax ; Joystick number into X
+ bne joy2
; Read joystick 1
-joy1: lda #$7F ; mask for VIA2 JOYBIT: sw3
- ldx #$C3 ; mask for VIA1 JOYBITS: sw0,sw1,sw2,sw4
- sei ; necessary?
+joy1: lda #$7F ; mask for VIA2 JOYBIT: sw3
+ ldx #$C3 ; mask for VIA1 JOYBITS: sw0,sw1,sw2,sw4
+ sei ; necessary?
- ldy VIA2_DDRB ; remember the date of DDRB
- sta VIA2_DDRB ; set JOYBITS on this VIA for input
- lda VIA2_JOY ; read JOYBIT: sw3
- sty VIA2_DDRB ; restore the state of DDRB
- asl ; Shift sw3 into carry
+ ldy VIA2_DDRB ; remember the date of DDRB
+ sta VIA2_DDRB ; set JOYBITS on this VIA for input
+ lda VIA2_JOY ; read JOYBIT: sw3
+ sty VIA2_DDRB ; restore the state of DDRB
+ asl ; Shift sw3 into carry
- ldy VIA1_DDRA ; remember the state of DDRA
- stx VIA1_DDRA ; set JOYBITS on this VIA for input
- lda VIA1_JOY ; read JOYBITS: sw0,sw1,sw2,sw4
- sty VIA1_DDRA ; restore the state of DDRA
+ ldy VIA1_DDRA ; remember the state of DDRA
+ stx VIA1_DDRA ; set JOYBITS on this VIA for input
+ lda VIA1_JOY ; read JOYBITS: sw0,sw1,sw2,sw4
+ sty VIA1_DDRA ; restore the state of DDRA
- cli ; necessary?
- ror ; Shift sw3 into bit 7
- and #$9E ; Mask relevant bits
- eor #$9E ; Active states are inverted
+ cli ; necessary?
+ ror ; Shift sw3 into bit 7
+ and #$9E ; Mask relevant bits
+ eor #$9E ; Active states are inverted
- rts
+ rts
; Read joystick 2
-joy2: lda #%10000000 ; via port B Data-Direction
- sta VIA1_DDRB ; bit 7: out bit 6-0: in
+joy2: lda #%10000000 ; via port B Data-Direction
+ sta VIA1_DDRB ; bit 7: out bit 6-0: in
- dex
- bne joy3
+ dex
+ bne joy3
- lda #$80 ; via port B read/write
- sta VIA1_PRB ; (output one at PB7)
+ lda #$80 ; via port B read/write
+ sta VIA1_PRB ; (output one at PB7)
- lda VIA1_PRB ; via port B read/write
- and #$1f ; get bit 4-0 (PB4-PB0)
- eor #$1f
- rts
+ lda VIA1_PRB ; via port B read/write
+ and #$1f ; get bit 4-0 (PB4-PB0)
+ eor #$1f
+ rts
; Read joystick 3
-joy3: lda #$00 ; via port B read/write
- sta VIA1_PRB ; (output zero at PB7)
+joy3: lda #$00 ; via port B read/write
+ sta VIA1_PRB ; (output zero at PB7)
- lda VIA1_PRB ; via port B read/write
- and #$0f ; get bit 3-0 (PB3-PB0)
- sta tmp1 ; joy 4 directions
+ lda VIA1_PRB ; via port B read/write
+ and #$0f ; get bit 3-0 (PB3-PB0)
+ sta tmp1 ; joy 4 directions
- lda VIA1_PRB ; via port B read/write
- and #%00100000 ; get bit 5 (PB5)
- lsr
- ora tmp1
- eor #$1f
+ lda VIA1_PRB ; via port B read/write
+ and #%00100000 ; get bit 5 (PB5)
+ lsr
+ ora tmp1
+ eor #$1f
- ldx #0
- rts
+ ldx #0
+ rts
projects / cc65 / blobdiff