As noted above, sprites will be partially or totally clipped if they pass
across or beyond the boundaries of the display window. The values of 64
(horizontal) and 44 (vertical) are "normal" for a centered display on a
standard NTSC video monitor. See Chapter 3, "Playfield Hardware," for more
information on  display offsets .  Information on PAL displays will be
found there. If you choose other values to establish your display window,
your sprites will be clipped accordingly.