Sprite RAM Bug
--------------

  There is a flaw in the GameBoy hardware that causes
 trash to be written to OAM RAM if the following commands
 are used while their 16-bit content is in the range
 of $FE00 to $FEFF:

  inc xx     (xx = bc,de, or hl)
  dec xx

  ldi a,(hl)
  ldd a,(hl)

  ldi (hl),a
  ldd (hl),a

  Only sprites 1 & 2 ($FE00 & $FE04) are not affected
 by these instructions.