diff --git a/main.s b/main.s
index 39ba642..388186a 100644
--- a/main.s
+++ b/main.s
@@ -18,6 +18,56 @@
 
 bg_pallets:
     .byte $0F, $30, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
+double_dabble:
+    lda #0
+    sta $01
+    sta $02
+    ldx #8
+dabble:
+    ; check first digit
+    lda $01
+    and #$F
+    jsr check
+    sta $03
+    lda #$F0
+    and $01
+    ora $03
+    sta $01
+    ; check second digit
+    lda $01
+    and #$F0
+    lsr
+    lsr
+    lsr
+    lsr
+    jsr check
+    asl
+    asl
+    asl
+    asl
+    sta $03
+    lda #$F
+    and $01
+    ora $03
+    sta $01
+    ; check third digit
+    lda $02
+    and #$F
+    jsr check
+    sta $03
+    lda #$F0
+    and $02
+    ora $03
+    sta $02
+    ; Shift
+    clc
+    rol $00
+    rol $01
+    rol $02
+    lda $00
+    dex
+    bne dabble
+    rts
 
 check:
     cmp #5
@@ -71,93 +121,46 @@ loop:
     bne loop
     lda #54
     sta $00
-    lda #0
-    sta $01
-    sta $02
-    ldx #8
-dabble:
-    ; check first digit
-    lda $01
-    and #$F
-    jsr check
-    sta $03
-    lda #$F0
-    and $01
-    ora $03
-    sta $01
-    ; check second digit
-    lda $01
-    and #$F0
-    lsr
-    lsr
-    lsr
-    lsr
-    jsr check
-    asl
-    asl
-    asl
-    asl
-    sta $03
-    lda #$F
-    and $01
-    ora $03
-    sta $01
-    ; check third digit
-    lda $02
-    and #$F
-    jsr check
-    sta $03
-    lda #$F0
-    and $02
-    ora $03
-    sta $02
-    ; Shift
-    clc
-    rol $00
-    rol $01
-    rol $02
-    lda $00
-    dex
-    bne dabble
-
-    lda $2002
-    lda #$20
-    sta $2006
-    lda #$20
-    sta $2006
-    lda $02
-    and #$F
-    cmp #0
-    bne :+
-    lda #10
-:   sta $2007
-    lda $01
-    and #$F0
-    lsr
-    lsr
-    lsr
-    lsr
-    cmp #0
-    bne :+
-    lda #10
-:   sta $2007
-    lda $01
-    and #$F
-    cmp #0
-    bne :+
-    lda #10
-:   sta $2007
-    
     lda #%10000000
     sta $2000
     lda #%00001010
     sta $2001
-    lda $2002
-    lda #0
-    sta $2005
-    sta $2005
 forever:
     jmp forever
 
 nmi:
+    inc $05
+    lda $05
+    sta $00
+    jsr double_dabble
+    lda $2002
+    lda #$20
+    sta $2006
+    lda #$20
+    sta $2006
+    lda $02
+    and #$F
+    cmp #0
+    bne :+
+    lda #10
+:   sta $2007
+    lda $01
+    and #$F0
+    lsr
+    lsr
+    lsr
+    lsr
+    cmp #0
+    bne :+
+    lda #10
+:   sta $2007
+    lda $01
+    and #$F
+    cmp #0
+    bne :+
+    lda #10
+:   sta $2007
+    lda #0
+    sta $2005
+    sta $2005
     rti
\ No newline at end of file