Sorry to bring up an old thread, but I talked with a TI employee who said that the "4" was chosen as a middling number, so they could go up and down if they introduced better/lower models (like the 99/2 and the planned original 99/3 that was to be released in 1979 with the 99/4 as a lower cost model).
I think this is quite reasonable. The 99/4 was concepted at the same time the 99/3 was concepted. Further there was a 99/7 concepted. And a super secret project was building yet another 9900 based computer. Susan Bailey was in that project before it was canceled and the employees were moved to support on developing the 99/4. When comparing the specs of the 99/7 to the project she was in, she insists on theirs being a different one, and their project starting in 1977. Susan later did do the Editor/Assembler and TI-Writer for our 99/4A.
What else to take into account about the 4 in our 99/4?
- Originally up to 4 joysticks planned
- 4 Phase clock phase
- 8-bit Cpu was planned, maybe with some limitation to the number 4
- there were talks with Milton Bradley about a game machine before the 99/4, maybe naming one or more predecessor projects and 4 might have been the natural next number
- it all started with 4 Gamevision Cartridges from Milton Bradley
Some interesting note from the interview with Granville Ott, done by Dan Eicher in 2004:
"... Len [Donohoe] wanted to develop an affordable home computer and assigned me as the architect. We presented the initial concept starting as a game and expanding to a full function computer to the corporate developmentcommittee in the fall of 1976. The committee wanted a less gamey image and we returned with the conceptfor the 99/4. ..."
"Q. Who designated the name 99/4. We've always understood the 99 to come from the 9900, and the 4 from the original 4K of video RAM. There is a bit in one of the video registers to choose 4K or 16K or video RAM. Were any machines actually sold with only 4K or VDP RAM?
A. We needed a series that didn’t look like a calculator name and had room for growth The 99 would tie to Austin if we could ever get them on board and to the Semiconductor product. 4 was a good starting place. The 16Ks were not affordable when we started so we designed for both 4 and 16. Semiconductor wanted us to use partials rejected from 16 production, but we refused. The 16s were available when we went to production."
Also the CC-40 is using 40 in its name. Why?