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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.
146 lines
3.2 KiB
ArmAsm
146 lines
3.2 KiB
ArmAsm
;
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; PTV-4 Player joystick driver for the C64
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;
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; Groepaz/Hitmen, 2002-12-23
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; obviously based on Ullrichs driver :)
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;
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.include "zeropage.inc"
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.include "joy-kernel.inc"
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.include "joy-error.inc"
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.include "c64.inc"
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.macpack generic
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.macpack module
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; ------------------------------------------------------------------------
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; Header. Includes jump table
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module_header _c64_ptvjoy_joy
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; Driver signature
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.byte $6A, $6F, $79 ; "joy"
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.byte JOY_API_VERSION ; Driver API version number
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; Library reference
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.addr $0000
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; Jump table.
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.addr INSTALL
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.addr UNINSTALL
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.addr COUNT
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.addr READ
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; ------------------------------------------------------------------------
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; Constants
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JOY_COUNT = 4 ; Number of joysticks we support
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.code
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; ------------------------------------------------------------------------
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; INSTALL routine. Is called after the driver is loaded into memory. If
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; possible, check if the hardware is present and determine the amount of
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; memory available.
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; Must return an JOY_ERR_xx code in a/x.
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;
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INSTALL:
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lda #<JOY_ERR_OK
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ldx #>JOY_ERR_OK
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; rts ; Run into UNINSTALL instead
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; ------------------------------------------------------------------------
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; UNINSTALL routine. Is called before the driver is removed from memory.
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; Can do cleanup or whatever. Must not return anything.
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;
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UNINSTALL:
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rts
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; ------------------------------------------------------------------------
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; COUNT: Return the total number of available joysticks in a/x.
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;
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COUNT:
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lda #<JOY_COUNT
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ldx #>JOY_COUNT
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rts
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; ------------------------------------------------------------------------
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; READ: Read a particular joystick passed in A.
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;
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READ: tax ; Joystick number into X
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bne joy2
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; Read joystick 1
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joy1: lda #$7F
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sei
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sta CIA1_PRA
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lda CIA1_PRB
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cli
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and #$1F
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eor #$1F
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rts
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; Read joystick 2
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joy2: dex
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bne joy3
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lda #$E0
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ldy #$FF
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sei
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sta CIA1_DDRA
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lda CIA1_PRA
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sty CIA1_DDRA
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cli
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and #$1F
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eor #$1F
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rts
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; Read joystick 3
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joy3:
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lda #%10000000 ; cia 2 port B Data-Direction
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sta CIA2_DDRB ; bit 7: out bit 6-0: in
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dex
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bne joy4
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lda #$80 ; cia 2 port B read/write
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sta CIA2_PRB ; (output one at PB7)
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lda CIA2_PRB ; cia 2 port B read/write
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and #$1F ; get bit 4-0 (PB4-PB0)
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eor #$1F
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rts
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; Read joystick 4
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joy4: lda #$00 ; cia 2 port B read/write
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sta CIA2_PRB ; (output zero at PB7)
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lda CIA2_PRB ; cia 2 port B read/write
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and #$0F ; get bit 3-0 (PB3-PB0)
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sta tmp1 ; joy 4 directions
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lda CIA2_PRB ; cia 2 port B read/write
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and #%00100000 ; get bit 5 (PB5)
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lsr
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ora tmp1
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eor #$1F
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ldx #0
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rts
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