3 ms·
Ken Shirriff has an excellent series of blog posts on early Intel chips (running from 4004 to 8086 I think). Don't believe he's done one on the 8080 but the pos
by klelatti 6y ago
Ken Shirriff has an excellent series of blog posts on early Intel chips (running from 4004 to 8086 I think). Don't believe he's done one on the 8080 but the post on the 8008 is great [1] and I'd expect that the 8080 (which followed it and was designed by the same team) is very similar.
In short no microcode but there is a PLA (Programmable Logic Array) which helps to decode the instructions.
[1] http://www.righto.com/2016/12/die-photos-and-analysis-of_24.html http://www.righto.com/2016/12/die-photos-and-analysis-of_24....
- kens 6y agoThanks for the nice comment! I haven't looked into the 8080 because other people have examined it in detail. See https://news.ycombinator.com/item?id=24101956 https://news.ycombinator.com/item?id=24101956 for an exact Verilog representation of the 8080.