;license:MIT
;(c) 2020 by qkumba

!cpu 6502
!to "build/PRELAUNCH.INDEXED/GUMBALL",plain
*=$106

    !source "src/macros.a"

         +ENABLE_ACCEL
         lda   #$60
         sta   $851
         jsr   $800       ; load "DOS"
         lda   #$20
         sta   $B21E
         lda   #<callback
         sta   $B21F
         lda   #>callback
         sta   $B220
         +DISABLE_ACCEL
         jmp   $B2F1

callback
         lda   $5F
         asl
         bne   +
         dec   $E09
+        rts

!if * > $1C0 {
  !error "code is too large, ends at ", *
}