4cade/src/demo/thunder.bombs.a

;license:MIT
;(c) 2021-2022 by Frank M., qkumba

!cpu 6502
!to "build/DEMO/THUNDER.BOMBS#06B000",plain
*=$B000

         !source "src/constants.a"   ; no code in these
         !source "src/macros.a"

         +READ_RAM2_WRITE_RAM2
         +LOAD_FILE_KEEP_DIR thunder_bombs, thunder_bombs_dir_e-thunder_bombs_dir_b
         +READ_ROM_NO_WRITE
         lda   #$60
         sta   $887F
         ldx   #3-1
-        lda   patch,x
         sta   $8819,x
         dex
         bpl   -
         jsr   $87F9      ; load, show title

         lda   #$60
         sta   $7818
         jsr   $7800      ; unpack/setup

         lda   #0
         sta   $3F2       ; reset vector

         ldx   #3-1
-        lda   patch2,x
         sta   $789B,x
         sta   $78CB,x
         sta   $7A8C,x
         sta   $7837,x    ; set exits
         dex
         bpl   -

         lda   $323
         jmp   $781B

callback bit   $C000
         ldx   #$30
-        bit   $C055
         lda   #$0B
         jsr   $FCA8
         bit   $C054
         lda   #$0B
         jsr   $FCA8
         bit   $C000
         bmi   exit
         dey
         bne   -
         dex
         bne   -
         jmp   $8839
exit
patch2   !byte $4C,$00,$01

patch    !byte $4C,<callback,>callback

thunder_bombs
         !byte thunder_bombs_e-thunder_bombs_b
thunder_bombs_b
thunder_bombs_dir_b
         !text "X/THUNDER.BOMBS"
thunder_bombs_dir_e
         !text "/THUNDER.BOMBS"
thunder_bombs_e

!if * > $B100 {
  !error "code is too large, ends at ", *
}