Gigatron: An 8-bit CPU built from 34 74LS TTL logic chips
hackaday.io
hackaday.io
> To reduce the parts count, every hardware function is essentially software-defined: video, audio and I/O are all handled by software. Video at the pixel level. Audio at the sample level, in 4 channels. Even the applications themselves are running in a non-existent 16-bit processor (aka interpreter).
Reminds me of what I read about the Xerox PARC Alto. They got a lot done with a minimal set of chips. (A bit-slice CPU I think?)
> Alto’s CPU was an extremely revolutionary microcode processor that employed microcode rather than hardware for most I/O activities. The microcode machine featured 16 tasks, one of which performed the standard instruction set and the others for display, memory refresh, disk, network, and other I/O functions.
But yeah the alto became my new favorite even though it’s way before my time when I saw the cpu card for it, and I really see no reason to take exception to the 74181 other than it’s too complex— the whole ti 74xx series is complex in retrospective. Unless this is somebody with the means to substantiate lithography for many of the TI chips but not the 4bit slice alu, then I’m not really sure what their hang up is with it.