*= $6000

; os memory map
CLRTEXT = $c050
SETTEXT = $c051
CLRMIXED = $c052
SETMIXED = $c053
TXTPAGE1 = $c054
TXTPAGE2 = $c055
CLRHIRES = $c056
SETHIRES = $c057

; ROM entry points
COUT = $fded
ROMWAIT = $fca8

; Zero page locations we use (unused by Monitor, Applesoft, or ProDOS)
PARAM0          = $06
PARAM1          = $07
PARAM2          = $08
PARAM3          = $09
SCRATCH0        = $19
SCRATCH1        = $1a
SPRITEPTR_L     = $1b
SPRITEPTR_H     = $1c

start   
    bit CLRTEXT     ; start with HGR page 1, full screen
    bit CLRMIXED
    bit TXTPAGE1
    bit SETHIRES

    jmp draw

    jsr clrscr

    ldx #0
loop
    txa
    sta $2000,x
    inx
    bne loop

draw
    lda #100
    sta PARAM1 ; y coord
    lda #100
    sta PARAM0 ; x coord

    jsr BWSPRITE

wait
    jmp wait


clrscr
    lda #0
    sta clr1+1
    lda #$20
    sta clr1+2
clr0
    lda #$81
    ldy #0
clr1
    sta $ffff,y
    iny
    bne clr1
    inc clr1+2
    ldx clr1+2
    cpx #$40
    bcc clr1
    rts

    .include bwsprite.s
    .include rowlookup.s
    .include collookupbw.s