4cade/src/demo/nibbler.a

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

!cpu 6502
!to "build/DEMO/NIBBLER#060300",plain
*=$300

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

         +ENABLE_ACCEL_LC
         +LOAD_XSINGLE title

         lda   #$60
         sta   $8A19
         jsr   $6550      ; decompress and show title

         lda   #$0A
         sta   $1984
         ldx   #3-1
-        lda   patch,x
         sta   $1984+1,x
         sta   $166D,x
         sta   $0981,x
         sta   $11BC,x    ; set exits
         lda   patch2,x
         sta   $165C,x    ; disable button detection
         dex
         bpl   -

         stx   $0914      ; disable sound

         +DISABLE_ACCEL

         jmp   $900

patch    !byte $4C,$00,$01
patch2   !byte $A9,$01,$EA

title    +PSTRING "NIBBLER"

!if * > $3F0 {
  !error "code is too large, ends at ", *
}