You don't know this, but I'm actually a Texas Instruments fanboy, pretty much. But not of the TI-99/4a, although I like it. I'm a fan of the TI Professional Computer and its derivatives. I'm also a fan of their failed computer projects, and among them is the TMS340x0 graphics processor line. The creator (Karl Guttag) wanted it to be the GPU/CPU for a video game console, but that never happened. A friend of the family named Raj worked at TI Bedford when it was being developed and ended up being the local guru for the architecture. It was eventually used in some arcade machines like Hard Drivin'.
There's a little known demo from 1987 on youtube for that particular graphics processor showing a game. It's called Captain Pixel, and it was written by Michael Denio. I think this was the precursor to Captain Comic.
Here's a link: