Here is my first 2-minute week video for uCISC, my CISC instruction set designed for homebrew computers. It's a little strange because this is a bit more than a week of work since this is my first one, but hopefully it gets it started and I can post every week now on smaller increments of progress.

FYI you should always feel free to talk about more than just what happened last week. Often we need to give context for what we did, because viewers may not have seen all past videos (or even any past videos).

I didn't see a url in your video. Do you have that fancy documentation hosted anywhere yet?

@Robert Butler See?! 🙂 @Ray Imber https://github.com/grokthis/ucisc has the docs, and https://github.com/grokthis/ucisc-ruby has the emulated hardware.

Noted 🙂 ... thanks for posting the links too.

I'm definitely the target audience for this kind of project lol. @Kartik Agaram's Mu as well. I have some similar history. I learned the very basics of hardware in college, I have followed Ben Eater off and on since he started, and a few years ago I became really invested in the (now semi-famous?) Nand2Tetris course, which I still love. I just never had the time or energy to take those ideas to the next level and actually do my own project. It's inspiring for me to see other people going for it!

I'm certainly planning to contribute to it.

@Ray Imber I'm glad to hear you are in the target audience. If you are that into it, I would love a subscribe over on my YouTube channel. I'm aiming for a video every MWF marching along towards a homebrew computer built on this. https://www.youtube.com/channel/UCh4OpfF7T7UtezGejRTLxCw

@Robert Butler Your architecture seems very GPU like: A bunch of tiny cores with local memory, and a way to access larger common memory (Also kind of Cray like). You talk about wanting to hit 1080p at 60Hz and supporting modern displays. How are you thinking about physically getting the video signal out? Are you planning on implementing your own HDMI controller? I'm curious because I looked at the HDMI spec once and got very overwhelmed lol.

Most likely I'll end up with an HDMI controller chip. I'm not particularly interested in implementing the signal elements of a computer as much as I am how they are exposed to the processor itself.

I feel like HDMI is a huge rabbit hole either way. Even if you get a controller, you are going to end up having to spend precious logic gates to massage it into what ever weird format and timings the controller wants. From what I've seen, VGA is crazy, but tractable at least. HDMI is frustratingly opaque... I think your idea to iteratively level up is a really good one! push that nonsense off as long as you can 🙂

@Ray Imber to be clear. I've read the HDMI spec too and ooh boy.... one of the problems with HDMI is I think it tries to do too much and be too much with so many different formats. Anyway, yeah... hopefully my delay tactic will pay off.

The Wikipedia on CUDA is actually a pretty good description of modern GPU architecture if you are interested: https://en.wikipedia.org/wiki/Thread_block_(CUDA_programming) You are purposely ignoring pre-emption and you obviously aren't doing any SIMD, but if you squint, it looks similar. Especially at the Streaming multiprocessor level.

Added that to my to-read list for when I'm a bit fresher. Thanks!

I really like the idea of building everything from scratch, from the hardware to the software, to allow the user grasps what is going on. Good luck and have fun with that project!! 🙂

Thanks Nicolas!