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1976d6cd32
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.
116 lines
2.9 KiB
ArmAsm
116 lines
2.9 KiB
ArmAsm
;
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; PTV-2 Player joystick driver for the PET
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;
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; Stefan Haubenthal, 2005-05-25
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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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.macpack module
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; ------------------------------------------------------------------------
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; Header. Includes jump table
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module_header _pet_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 = 2 ; Number of joysticks we support
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VIA_PRA := $E841 ; Port register A
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VIA_DDRA := $E843 ; Data direction register A
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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: lda #%10000000 ; via port A Data-Direction
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sta VIA_DDRA ; bit 7: out bit 6-0: in
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tax ; Joystick number into X
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bne joy2
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; Read joystick 1
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joy1: lda #$80 ; via port A read/write
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sta VIA_PRA ; (output one at PA7)
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lda VIA_PRA ; via port A read/write
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and #$1f ; get bit 4-0 (PA4-PA0)
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eor #$1f
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rts
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; Read joystick 2
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joy2: lda #$00 ; via port A read/write
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sta VIA_PRA ; (output zero at PA7)
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lda VIA_PRA ; via port A read/write
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and #$0f ; get bit 3-0 (PA3-PA0)
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sta tmp1 ; joy 4 directions
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lda VIA_PRA ; via port A read/write
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and #%00100000 ; get bit 5 (PA5)
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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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