4cade/src/prelaunch/skyfox.a

;license:MIT
;(c) 2019-2020 by qkumba/Frank M.

!cpu 6502
!to "build/PRELAUNCH/SKYFOX",plain
*=$106

    !source "src/prelaunch/common.a"

         +ENABLE_ACCEL
         inc   $80        ; requires a non-zero value for the RNG
         lda   #$60
         sta   $7E31
         jsr   $4621

         lda   #$82       ; READ_ROM_NO_WRITE
         sta   $101
         lda   #$A6
         sta   $104
         lda   #$FA
         sta   $105       ; update TR hook to reboot
         lda   #0
         sta   $5FFC
         lda   #1
         sta   $5FFD      ; moved to LC $FFFC/D

         lda   #$4C
         sta   $6872
         lda   #<callback
         sta   $6873
         lda   #>callback
         sta   $6874
         lda   #$B0
         sta   $685B
         lda   #$90
         sta   $6862
         +DISABLE_ACCEL
         jmp   $67BD

callback
         sec
         sbc   #8
         cmp   #2
         rts

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