processor 6502
    include "basicheader.dasm"

Src equ $02
Dest equ $04

Start:
    lda #$38   ; 25 rows, on, bitmap
    sta $d011  ; VIC control #1
    lda #$18   ; 40 column, multicolor
    sta $d016  ; VIC control #2
    lda #$02
    sta $dd00  ; set VIC bank ($4000-$7FFF)
    lda #$80
    sta $d018  ; set VIC screen to $6000
    lda XtraData+0
    sta $d020  ; border
    sta $d021  ; background
    lda #0
    sta Dest
; copy char memory
    lda #<CharData
    sta Src
    lda #>CharData
    sta Src+1
    lda #$40
    sta Dest+1
    ldx #$20
    jsr CopyMem
; copy screen memory
    lda #<ScreenData
    sta Src
    lda #>ScreenData
    sta Src+1
    lda #$60
    sta Dest+1
    ldx #$04
    jsr CopyMem
; copy color RAM
    lda #<ColorData
    sta Src
    lda #>ColorData
    sta Src+1
    lda #$d8
    sta Dest+1
    ldx #4
    jsr CopyMem
; infinite loop
    jmp .

; copy data from Src to Dest
; X = number of bytes * 256
CopyMem
    ldy #0
.Loop
    lda (Src),y
    sta (Dest),y
    iny
    bne .Loop
    inc Src+1
    inc Dest+1
    dex
    bne .Loop
    rts

; bitmap data
CharData equ .
ScreenData equ CharData+8000
ColorData equ ScreenData+1000
XtraData equ ColorData+1000
    incbin "badspacerobots-c64.multi.bin"