Initial Creativision Import

libsrc/creativision/joy.s

@@ -0,0 +1,58 @@
+;*
+;* Creativision Joystick Function
+;* 
+;* unsigned char __fastcall__ joystate(unsigned char joy);
+;*
+;* JOY_1 -> Return Left Joystick direction
+;* JOY_2 -> Return Right Joystick direction
+;* JOY_3 -> Return Left Joystick buttons
+;* JOY_4 -> Return Right Joystick buttons
+;*
+;* Will only work if interrupts are enabled.
+
+        .export         _joystate
+        .include        "creativision.inc"
+        
+_joystate:
+        cmp             #1      ; Left Direction
+        bne             l1
+        
+        lda             $11
+        beq             l5
+        and             #$f
+        lsr             a
+        tax
+        inx
+        txa
+        rts
+        
+l1:     cmp             #2      ; Right Direction
+        bne             l2
+        
+        lda             $13
+        beq             l5
+        and             #$f
+        lsr             a
+        tax
+        inx
+        txa
+        rts
+        
+l2:     cmp             #3      ; Left Buttons
+        bne             l3
+        
+        lda             $16
+        beq             l5
+        and             #$f
+        rts
+        
+l3:     cmp             #4
+        bne             l4
+        
+        lda             $17
+        beq             l5
+        and             #$f
+        rts
+        
+l4:     lda             #0
+l5:     rts