CLSLayer2:
        ; d = colour to clear with
        ld bc,$123b
        in a,(c)
        push af
        ld a,1
        out (c),a
        ld  e,3
        ld  a,1
        ld  bc, $123b
    RepeatLoop:
        out (c),a
        push    af
        ld  hl,0
    ClearLoop:
        ld  (hl),d
        inc l
        jr  nz,ClearLoop
        inc h
        ld  a,h
        cp  $40
        jr  nz,ClearLoop
        pop af
        add a,$40
        dec e
        jr  nz,RepeatLoop
        ld  bc,$123b
        pop af
        out (c),a
        ret