4cade/src/demo/nibbler.a

;license:MIT
;(c) 2021 by Frank M.

!cpu 6502
!to "res/DEMO/NIBBLER",plain
*=$300

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

         +ENABLE_ACCEL
         +LOAD_XSINGLE title

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

         lda   #$A9
         sta   $165C
         lda   #$EA
         sta   $165C+2    ; disable button detection

         lda   #$0A
         sta   $1984
         lda   #$4C
         sta   $1984+1
         sta   $166D
         sta   $0981
         sta   $11BC
         lda   #0
         sta   $1984+2
         sta   $166D+1
         sta   $0981+1
         sta   $11BC+1
         lda   #1
         sta   $165C+1
         sta   $1984+3
         sta   $166D+2
         sta   $0981+2
         sta   $11BC+2    ; set exits

         lda   #$FF
         sta   $0914      ; disable sound

         +DISABLE_ACCEL

         jmp   $900

title    !byte x_e-x_b
x_b      !text "NIBBLER"
x_e

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