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Quote:

Originally Posted by Doug Sams

What all types of logic did you work with, Carl? I'm guessing DTL and RTL were the common types in the early 70s.

For me, coming out of school in 83, LS-TTL was king, and was soon replaced by FAST-TTL. I did many board designs with that back in the late 80s. That technology will always be my paradigm.

I was actually a bit saddened a few years ago when I learned that all bi-polar logic had gone by the wayside

Doug

(And no, Bill, bi-polar logic is not the term used to describe how schizophrenics think

)

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We had to interface with some old IBM RTL logic boards, but everything we did from 1971 was TTL. 7400 series was on all the production boards when I started. I remember that I had to memorize most the Texas Instruments TTL Databook so I did not have to keep looking everything up. My first computer I built in 1973 was all 7400 series I.C.'s. The most complex part was the 74181 arithmetic unit. It executed the PDP-8 instruction set. I used it at home, but I could not get anyone at Telex interested in building "toy computers."

When Intel introduced the 8008 microcomputer, I built a 7400 based board that executed the 8008 instruction set at 20 times the speed. Still no interest from Telex. The good part about it is that I always had a faster and better microcomputer in my basement than you could buy on the market.

I still design with 74HCT as glue. I just can't see the numbers on the surface mount parts. The sick joke is that as the early logic designers lose their eyesight, the IC companies make the parts even smaller. I used to laugh at my elders at Telex that carried a jeweler's loupe to see the parts back then. I did not realize I was laughing at my future self as well.