Nice. But if I remember correctly, Mode X was a special VGA mode to squeeze a bit more performance (due to planes and full graphics memory addressing), not the "normal" MCGA 320x200x256 (13h)
If you're interested, I also implemented a few effects like lens[0] and Jare's fire[1] along with some other amusements[2]
Thanks for sharing the link! I remember the lense demos, and I remember downloading one or two of them from a BBS that had NSFW pictures rendered in the background.
320x240 (square pixels) with 256 colours
Full details:
https://en.wikipedia.org/wiki/Mode_X