;
 
 SETDRAWPAGE:
-       cmp     #1
+               cmp     #1
                beq     @L1                 ; page == maxpages-1
                lda     #<$de20             ; page 0
                ldx     #>$de20
 SERIAL_INTERRUPT = TIMER4_INTERRUPT
 
 IRQ:
-       lda     INTSET          ; Poll all pending interrupts
-       and     #VBL_INTERRUPT
-        bne    IRQVBL
-       clc                     ; Not a VBL interrupt - exit
-       rts
-IRQVBL: 
-       lda     SWAPREQUEST
-       beq     @L0
-       lda     DRAWPAGE
-       jsr     SETVIEWPAGE
-       lda     DRAWPAGE
-       eor     #1
-       sta     DRAWPAGE
-       jsr     SETDRAWPAGE
-       stz     SWAPREQUEST
+               lda     INTSET          ; Poll all pending interrupts
+               and     #VBL_INTERRUPT
+        beq            IRQEND          ; Exit if not a VBL interrupt
+
+               lda     SWAPREQUEST
+               beq     @L0
+               lda     DRAWPAGE
+               jsr     SETVIEWPAGE
+               lda     DRAWPAGE
+               eor     #1
+               sta     DRAWPAGE
+               jsr     SETDRAWPAGE
+               stz     SWAPREQUEST
 @L0:
-       jsr     VBLHOOK
-       clc
-       rts
+               jsr     VBLHOOK
+IRQEND:
+               clc
+               rts
 
 ; ------------------------------------------------------------------------
 ; SETCOLOR: Set the drawing color (in A). The new color is already checked
 ; The Font
 ; 96 characters from ASCII 32 to 127
 ; 8 pixels wide, 8 pixels high
-; bit value 0 = foreground, bit value 1 = background / transparent 
+; bit value 0 = foreground, bit value 1 = background / transparent
 font:
 ; VERSAIL
        .byte $FF, $FF, $FF, $FF, $FF, $FF, $FF, $FF  ;32