2 ; PTV-2 Player joystick driver for the PET
4 ; Stefan Haubenthal, 2005-05-25
5 ; Groepaz/Hitmen, 2002-12-23
6 ; obviously based on Ullrichs driver :)
9 .include "zeropage.inc"
11 .include "joy-kernel.inc"
12 .include "joy-error.inc"
14 VIA_PRA := $E841 ; Port register A
15 VIA_DDRA := $E843 ; Data direction register A
17 ; ------------------------------------------------------------------------
18 ; Header. Includes jump table
24 .byte $6A, $6F, $79 ; "joy"
25 .byte JOY_API_VERSION ; Driver API version number
27 ; Button state masks (8 values)
34 .byte $00 ; JOY_FIRE2 unavailable
35 .byte $00 ; Future expansion
36 .byte $00 ; Future expansion
44 .addr 0 ; IRQ entry unused
46 ; ------------------------------------------------------------------------
49 JOY_COUNT = 2 ; Number of joysticks we support
54 ; ------------------------------------------------------------------------
55 ; INSTALL routine. Is called after the driver is loaded into memory. If
56 ; possible, check if the hardware is present and determine the amount of
58 ; Must return an JOY_ERR_xx code in a/x.
64 ; rts ; Run into UNINSTALL instead
66 ; ------------------------------------------------------------------------
67 ; UNINSTALL routine. Is called before the driver is removed from memory.
68 ; Can do cleanup or whatever. Must not return anything.
75 ; ------------------------------------------------------------------------
76 ; COUNT: Return the total number of available joysticks in a/x.
84 ; ------------------------------------------------------------------------
85 ; READ: Read a particular joystick passed in A.
88 READ: lda #%10000000 ; via port A Data-Direction
89 sta VIA_DDRA ; bit 7: out bit 6-0: in
91 tax ; Joystick number into X
96 joy1: lda #$80 ; via port A read/write
97 sta VIA_PRA ; (output one at PA7)
99 lda VIA_PRA ; via port A read/write
100 and #$1f ; get bit 4-0 (PA4-PA0)
106 joy2: lda #$00 ; via port A read/write
107 sta VIA_PRA ; (output zero at PA7)
109 lda VIA_PRA ; via port A read/write
110 and #$0f ; get bit 3-0 (PA3-PA0)
111 sta tmp1 ; joy 4 directions
113 lda VIA_PRA ; via port A read/write
114 and #%00100000 ; get bit 5 (PA5)