Removed IRQ support from joystick drivers.

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.

libsrc/joystick/joy-kernel.s

@@ -6,7 +6,6 @@
 
         .import         joy_libref
         .importzp       ptr1
-        .interruptor    joy_irq         ; Export as IRQ handler
 
         .include        "joy-kernel.inc"
         .include        "joy-error.inc"
@@ -26,7 +25,6 @@ joy_install:    jmp     $0000
 joy_uninstall:  jmp     $0000
 joy_count:      jmp     $0000
 joy_read:       jmp     $0000
-joy_irq:        .byte   $60, $00, $00   ; RTS plus two dummy bytes
 
 ; Driver header signature
 .rodata
@@ -73,18 +71,7 @@ _joy_install:
         cpy     #(JOY_HDR::JUMPTAB + .sizeof(JOY_HDR::JUMPTAB))
         bne     @L1
 
-        jsr     joy_install             ; Call driver install routine
-        tay                             ; Test error code
-        bne     @L2                     ; Bail out if install had errors
-
-; Install the IRQ vector if the driver needs it. A/X contains the error code
-; from joy_install, so don't use it.
-
-        ldy     joy_irq+2               ; Check high byte of IRQ vector
-        beq     @L2                     ; Jump if vector invalid
-        ldy     #$4C                    ; JMP opcode
-        sty     joy_irq                 ; Activate IRQ routine
-@L2:    rts
+        jmp     joy_install             ; Call driver install routine
 
 ; Driver signature invalid
 
@@ -108,9 +95,6 @@ copy:   lda     (ptr1),y
 ; */
 
 _joy_uninstall:
-        lda     #$60                    ; RTS opcode
-        sta     joy_irq                 ; Disable IRQ entry point
-
         jsr     joy_uninstall           ; Call the driver routine
 
 _joy_clear_ptr:                         ; External entry point

libsrc/joystick/joy_read.s

@@ -8,5 +8,3 @@
         .include        "joy-kernel.inc"
 
         _joy_read       = joy_read              ; Use driver entry
-
-