Here is my first contribution to this group, a blast from the past in the files I've been extracting from my TI/Geneve hard drive. This is a version of Tetris that I wrote back in 1989. I was able to run it on my newly resurrected Geneve (thanks, RickyDean!) and was able to run it in MAME as well. If I remember correctly, I tried to match the timing of the levels to the version I played on the Mac back then, which means level 9 is super-fast.
This was written for MDOS version 0.97R back in the day - not sure if it would work on a "modern" version without changes.
tetris.dsk 360KB 24 downloads