You can't use game sprites with the HAM mode, because HAM requires the "real palette" to be set (and adjusted) acording to the Image being shown... the Sprites would then have to use whatever base colours were chosen for the image, which would limit your choice of colours... and you would have to have a different set of sprites for every image (since each one would have a different "real palette")... the most sensible solution here is to use a graphics chip that is not from the last century :-D
