;license:MIT
;(c) 2020, 2022 by qkumba

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

my_vbl   

    !source "src/prelaunch/common.a"

         +READ_RAM1_NO_WRITE
         lda   WaitForVBL
         cmp   #$60
         beq   @skip_vbl
         lda   WaitForVBL+1
         sta   @copy_vbl+1
         lda   WaitForVBL+2
         sta   @copy_vbl+2

@skip_vbl
         lda   MachineStatus
         and   #CHEATS_ENABLED
         php
         ldy   #0

@copy_vbl
         lda   WaitForVBL,y
                          ; SMC, default to no VBL
         sta   my_vbl,y
         iny
         cmp   #$60
         bne   @copy_vbl
         sta   $207E
         jsr   $2000
         jsr   $939
         lda   #$4C
         sta   $9D52
         lda   #<my_vbl
         sta   $9D53
         lda   #>my_vbl
         sta   $9D54
         plp
         beq   +
         lda   #<callback
         sta   $8BB
         lda   #>callback
         sta   $8BC
+
         jmp   $881

callback
         lda   #$A5
         sta   $A453      ; patch - don't decrease time
         jmp   $B679

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