4 ms·
Pretty cool, but it isn't made from discrete logic gates. It's built from MSI TTL chips that contain a bunch of gates. And the ALU is a table lookup using two 1
by kens 11y ago
Pretty cool, but it isn't made from discrete logic gates. It's built from MSI TTL chips that contain a bunch of gates. And the ALU is a table lookup using two 1 megabyte ROMs. (Reminiscent of the old IBM 1620 which used a table lookup in core memory for arithmetic.)
- jacquesm 11y agoWould 'Homebrew Computer from 74HC* series except eprom, RAM and UARTs' work better for you?
- loup-vaillant 11y agoPersonally, I don't mind RAM. That's a given, even on an 8 bit computer, and a bigger RAM doesn't invalidate the rest. Look up table arithmetic on the other hand feels more like cheating: it makes multiplication as easy as bitwise XOR, and that kinda destroys my "retro" feel. Great choice however if the ALU bores you. Me, I'd lean towards a different kind of cheating: programmable chips such as the 22V10. Because of reasons. The "22V10 computer", how would that sound?
- jacquesm 11y agoHm, makes you wonder if you built an 8 bit computer entirely out of discrete components (transistors, resistors, diodes) how large it would be, and what clock you could still attain. Power usage would probably be pretty impressive too.
- loup-vaillant 11y agoThis guy http://www.megaprocessor.com/homebrew.html http://www.megaprocessor.com/homebrew.html may eventually find out.
- jacquesm 11y agoThat's absolutely amazing. http://www.megaprocessor.com/index.html http://www.megaprocessor.com/index.html I saw the thread on HN when it passed (even commented on it) and then promptly forgot. Thanks for the reminder.