Gregory's ServerManufacturing a chip requires an expensive mask for each layer, maybe 8 layers in a chip like this. But using a gate array, most of the masks can be reused across a product line, with only 2 custom masks for the metal layers. 10/13
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 The designers put their initials on the die. There are also mysterious symbols; one looks like the Chinese character "正" with a T below. 12/13 For more on this chip, see my blog post:  @kenshirriff The “正” character is sometimes used as a counter, in the same way we use 4 vertical lines and a slash through it to count to 5. That might be a “7”thing revision of something. https://en.m.wiktionary.org/wiki/正 @kenshirriff is this a precursor to modern FPGAs, in the sense that they mass-produced a chip that would be configured for a specific purpose at a later point? @guenther @kenshirriff Basically yes - It is a Gate Array, just not Field Programmable. And of a rather low complexity. Personally, I'm reminded of the Ferranti ULA (used in the Sinclair hole computers), which is a bit more complex, but also mask programmed. https://en.wikipedia.org/wiki/Gate_array#Development |
A gate array makes each chip more expensive to manufacture because of the wasted die area. But the fixed mask costs are much lower. So a gate array is cheaper when making chips in lower quantities. This made sense for IDT, selling low-volume, high-markup military parts. 11/13