add joystick driver -- trigger buttons are not queried yet

libsrc/atari5200/joy/atr5200std.s

@@ -0,0 +1,130 @@
+;
+; Standard joystick driver for the Atari 5200.
+;
+; Christian Groessler, 2014-05-12
+;
+
+        .include        "zeropage.inc"
+
+        .include        "joy-kernel.inc"
+        .include        "joy-error.inc"
+        .include        "atari5200.inc"
+
+
+; ------------------------------------------------------------------------
+; Header. Includes jump table
+
+.segment        "JUMPTABLE"
+
+; Driver signature
+
+        .byte   $6A, $6F, $79           ; "joy"
+        .byte   JOY_API_VERSION         ; Driver API version number
+
+; Library reference
+
+        .addr   $0000
+
+; 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   $20                     ; JOY_FIRE2
+        .byte   $00                     ; Future expansion
+        .byte   $00                     ; Future expansion
+
+; Jump table.
+
+        .addr   INSTALL
+        .addr   UNINSTALL
+        .addr   COUNT
+        .addr   READJOY
+        .addr   0                       ; IRQ entry not used
+
+; ------------------------------------------------------------------------
+; Constants
+
+JOY_COUNT       = 4             ; 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     #0
+;       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     #0
+        rts
+
+; ------------------------------------------------------------------------
+; READ: Read a particular joystick passed in A.
+;
+
+CENTER	=	228 / 2
+SENSIVITY	= 16
+
+READJOY:
+        and     #3              ; fix joystick number
+	asl	a
+        tax                     ; Joystick number * 2 (0-6) into X, index into ZP shadow registers
+	lda	#0		; Initialize return value
+
+; Read joystick
+
+	ldy	PADDL0,x	; get horizontal position
+	cpy	#CENTER-SENSIVITY
+	bcs	@chkleft
+
+	ora	#4		; JOY_LEFT
+	bne	@updown
+
+@chkleft:
+	cpy	#CENTER+SENSIVITY
+	bcc	@updown
+
+	ora	#8		; JOY_RIGHT
+
+@updown:ldy	PADDL0+1,x	; get vertical position
+	cpy	#CENTER-SENSIVITY
+	bcs	@chkdown
+
+	ora	#1		; JOY_UP
+	bne	@buttons
+
+@chkdown:
+	cpy	#CENTER+SENSIVITY
+	bcc	@buttons
+
+	ora	#2		; JOY_DOWN
+
+@buttons:
+	; @@@ TODO: BOTTON STATE
+
+	rts
+

libsrc/atari5200/joy_stat_stddrv.s

@@ -0,0 +1,12 @@
+;
+; Address of the static standard joystick driver
+;
+; Christian Groessler, 2014-05-12
+;
+; const void joy_static_stddrv[];
+;
+
+        .export _joy_static_stddrv
+        .import _atr5200std_joy
+
+_joy_static_stddrv := _atr5200std_joy

libsrc/atari5200/libref.s

@@ -0,0 +1,8 @@
+;
+; Christian Groessler, 2014-05-12
+;
+
+        .export         joy_libref
+        .import         _exit
+
+joy_libref      := _exit