Game Console Ancestor of 99/4?

[segaloco]

So in various study over the years, my understanding is that the Ti-99/4 design incorporates parts and descends from earlier development of a home game console in the mid to late 70s, with market pressures and internal politics at Ti resulting in the cancelation of that project and merge of some of the developments into the 99/4 effort.

Does any actual material from this period exist describing in any detail the embryonic console, what proposed features *didn't* make it to the 99/4, whether a functioning unit was ever built and demonstrated, or if the "big picture" never left the drafting table and all they had in hand at the time of project cancelation were the various subsystems sampled into the 99/4?

Given the TMS9918 used in this computer inspired numerous home game console video controllers, it seems Ti was on the right track regarding useful hardware design in video games. If any amount of relatively complete design specifications exist out in the world, seeing to completion of a theoretical Ti game console would be quite the fun project.

 

[krebizfan]

https://www.videogamehouse.net/gamemain/cartsfh/gamevisiondemo/ offers the Milton Bradley side of the precursor to the TI-99/4. One could see what the Game Vision games look like to have an idea of what the console would have been like.

 

[jbdigriz]

From Klaus Lukaschek's interview with Herman Schuurman, https://forums.atariage.com/topic/295223-historical-interviews-with-ti-employees/#comment-4335684:

"Before I arrived in Lubbock, there was some work done on a native GPL chip, but by 1978 that had been replaced with an 8-bit TMS9985 based design. Unfortunately, that chip never ran correctly, so we had to eventually fit a 16-bit TMS9900 into an 8-bit design. If you like to see more info on the 9985 design debacle, check out Karl Guttag’s page at http://www.kguttag.com/2013/08/10/if-you-havent-tested-it-it-doesnt-work"

and...

" Q) Why was the native GPL chip replaced with the TMS9985? How far was the GPL chip developed?

Although it was before my arrival in Lubbock, the GPL chip was supposed to be developed for an external customer. When that customer dropped out, the GPL chip was also dropped, and was replaced by the TMS9985."

Something about M/B in this context is ringing a bell for me but I don't have all my notes handy atm.

The comments in Guttag's blog post do give further insight into the performance issues of GPL programs running from VDP ram, among other things. Interestingly, he also mentions Colin Hinson's plug-in TMS9995-based CPU accelerator board that sped up the TI99 by about 4X.