Driver for Protovision 4 Player Joystick by Stefan Haubenthal

git-svn-id: svn://svn.cc65.org/cc65/trunk@3595 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/vic20/Makefile

@@ -61,7 +61,7 @@ OBJS =	_scrsize.o	\
 
 EMDS =
 
-JOYS = vic20-stdjoy.joy
+JOYS = vic20-stdjoy.joy vic20-ptvjoy.joy
 
 TGIS =
 

libsrc/vic20/vic20-ptvjoy.s

@@ -0,0 +1,146 @@
+;
+; PTV-3 Player joystick driver for the VIC20
+;
+; Stefan Haubenthal, 2005-05-25
+; Groepaz/Hitmen, 2002-12-23
+; obviously based on Ullrichs driver :)
+; Using code from Steve Schmidtke
+;
+
+	.include "zeropage.inc"
+
+	.include "joy-kernel.inc"
+	.include "joy-error.inc"
+	.include "vic20.inc"
+
+; ------------------------------------------------------------------------
+; Header. Includes jump table
+
+	.segment "JUMPTABLE"
+
+; Driver signature
+
+	.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
+
+; Jump table.
+
+	.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
+
+
+.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
+
+
+; ------------------------------------------------------------------------
+; 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	#$7F		; mask for VIA2 JOYBIT: sw3
+	ldx	#$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	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
+
+	rts
+
+; Read joystick 2
+
+joy2:	lda	#%10000000	; via port B Data-Direction
+	sta	VIA1_DDRB	; bit 7: out	bit 6-0: in
+
+	dex
+	bne	joy3
+
+	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)
+	rts
+
+; Read joystick 3
+
+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	#%00100000	; get bit 5 (PB5)
+	lsr
+	ora	tmp1
+
+	ldx	#0
+	rts
+