;
; example.asm for TR8
;
.org 0

    ; setup an int handler so we
    ; can use the frame int to sync
    ld a, 0xff
    ld x, 0
    ld b, <int_handler
    ld [a : x], b
    inc x
    ld b, >int_handler
    ld [a : x], b

    ; enable interrupts
    cif

    ; loop filling the screen with one
    ; colour cycling the whole palette
    ld b, 0
loop:
    call fill
    inc b
    and b, 15

    ; wait 1 second
    ld x, 60
wait_loop:
    halt
    dec x
    bnz
    jmp wait_loop

    jmp loop

    ; fill frame-buffer with a color in reg b
fill:
    ld a, 0xbf
    ld x, 0
    ld y, 0x40
fill_loop:
    ld [a : x], b
    inc x
    bno
    jmp fill_loop
    inc a
    dec y
    bnz
    jmp fill_loop
    ret

int_handler:
    iret