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the size difference and design technique between Intel and TI is telling. Even though they are both of the same generation of chip Intel was just years ahead in
by Shivetya 12y ago
the size difference and design technique between Intel and TI is telling. Even though they are both of the same generation of chip Intel was just years ahead in efficiency. The TI almost looks like a "will this work" or "that will do" type design.
- hga 12y agoYeah, and the vastly greater size fed directly into it not being commercially viable because of massively lower yield, all things being equal. Add an unrealistic requirement for ultra clean power, and the thesis of the article is quite debatable; this chip "worked in the lab" but was not viable outside of it. Perhaps a good learning experience for TI, but hard to see more than that.
- agumonkey 12y agoInteresting facts about realism. Being first is very relative.
- kens 12y agoAuthor here. One key difference between the Intel and TI layout is that Federico Faggin (who later created the Z80) brought silicon gate technology to Intel from Fairchild. This provided much better transistor performance. But it also provided a layer of polysilicon "wiring", which made routing much easier. (Kind of like routing a single-sided printed circuit board vs a double-sided board.) This gave Intel a huge advantage in layout. But even taking that into account, the TI layout is kind of terrible. Silicon gate info: https://en.wikipedia.org/wiki/Self-aligned_gate#The_Development_of_the_Silicon_Gate_Technology_at_Fairchild_Semiconductor https://en.wikipedia.org/wiki/Self-aligned_gate#The_Developm...
- userbinator 12y agoWas TI using the same feature size as Intel? The 4004 and 8008 were 10-micron, but the TMX1795 looks like it was a larger process - fron the comparative photo I can nearly read the bits off the decode PLAs on it, whereas it's a lot harder with the 4004 and basically impossible on the 8008 die.