Hi Folks,
I am building myself a retro-style, single board computer. I've picked a 65C02 for the microprocessor, have 32K static RAM, and up to 32K ROM possible. I want to pick out the right chips for the GLUE logic, to minimize propagation delays, because I couldn't resist the temptation to perhaps overdo the logic levels a little bit in order to spell out exactly what I wanted for the memory map.
I've always been under the assumption that HCT parts would be faster than LS parts (I'm using 7400, 7404, 7432, and 74138)..
However, when reading the datasheets, somehow the 7400 LS part is MUCH faster than the 7400 HCT part I am comparing it to, which makes my assumption seem wrong.. And, I also see HC parts.. Google searching this stuff has got me even more confused: HCT is for TTL? I'm using the GLUE logic with RAM and ROM chips that are CMOS, so this may not matter?
Can anyone summarize what the differences are between LS, HC, HCT, etc?
Which is fastest? Which do I want?
Thanks!
Jason
PS: If you want to see what I've come up with so far with this computer build, here is my youtube channel where I've so far documented it:
https://www.youtube.com/channel/UCMZK0Uxfzq5eCyX5JoOO4qA