BITSIZE
Output the width and height of the bitmap specified by the current BITINDEX. The output is a two-member list of the form [width height]. BITSIZE outputs [0 0] if no bitmap is loaded.
SHOW BITSIZE [0 0] BITCOPY 100 200 SHOW BITSIZE [100 200]
SHOW BITSIZE
BITCOPY 100 200 SHOW BITSIZE