Build a Superscalar 8-Bit CPU (YouTube Playlist) [video]

136 pointsposted 4 months ago
by lrsjng
(youtube.com)

19 Comments

globular-toast

4 months ago

I built Ben Eater's 8 bit computer on breadboards a few years ago. It's a challenging but super rewarding project. I felt like after years of doing computer stuff I could finally say I get how it all works right down to the level of electronics, plus I learnt some new skills and got really good at cutting little wires to exactly the right length. It takes some dedication, especially when you're building the same register module 3+ times, but I found it quite relaxing in the evenings, similar to knitting in many ways.

I'm glad to see there are more projects in case I want to do it again some day...

Graziano_M

4 months ago

I bought the kit and was making progress with it, but unfortunately you have to be extremely lucky to have it work with the way Ben wired it. He skips a lot of pull downs and such, and adding all that is such a chore. More importantly, it can’t really fit on the breadboards with the additional required circuitry, so you end up making a monstrosity that doesn’t doesn’t look anything like his, which really takes away from the value of his lessons.

globular-toast

4 months ago

Hmm... I didn't have this experience at all. Apart from dotting a bunch of capacitors around the busses I didn't have to do much differently. I was able to find the exact components he used myself on Mouser. It's been a while though so maybe I'm forgetting something or maybe I was just lucky as you say. I should really dig it out and see if it still works.

The only major thing I changed was I designed my own EEPROM programmer as I found the way he was doing it laborious.

Graziano_M

4 months ago

Maybe you were! I got the clock working well but none of the register modules worked correctly. I asked in the subreddit and apparently it’s asked a ton because Ben keeps a lot of stuff floating and for most that doesn’t work. I don’t mind having to do it but it’s annoying to have to find extra parts and extra annoying having to try to have it fit in the original footprint so that each breadboard still fits together as in the videos.

globular-toast

4 months ago

I pulled mine out to see if I could jog my memory. The floating issue rings a bell but I seem to remember the TI chips had built-in pulldown resistors. I think I found actual TI chips, was it a problem with the clones perhaps? Are there other variables in the circuitry that would make this not work for some people but work for others?

The project definitely gave me an appreciation for electronics and how much is hidden under that abstraction level. I really wish I'd kept a journal or blog while doing mine!

Graziano_M

4 months ago

I forget the details since I haven't touched it in some time, but that sounds familiar. I think I remember being annoyed that I was given clones despite buying the kit from hit directly.

You could rip it apart and do it again from scratch! You'd definitely learn some stuff you missed the first time. Of course, you could just try the project in OP's link instead.

zkmon

4 months ago

Some channels like these are like collectibles. They are far above over the stature of Youtube itself. Unfortunately we don't have any other place to have these collectibles at, except on a service owned by a private company, who runs it for their business goals.

globular-toast

4 months ago

Agreed. I have been personally archiving anything I find high quality for a while now. YouTube is fighting that, though. I hope one day we can get past this and just share this stuff in a distributed way (like BitTorrent).

I still think what we lack is an easy way to do the busking model online. I refuse to pay by watching ads, and I refuse to further monopolies and contribute to garbage like MrBeast by paying for YouTube Premium or whatever. But if I could regularly pay into an account, say £20/month, and choose where to allocate that to each month by doing something low friction like clicking a button that would be perfect. I don't want to automatically pay for everything I see because I don't think it's all worth it. I'm not forced to pay for buskers in public just because I heard them.

I think we have all the pieces we need for this kind of system, namely BitTorrent, Bitcoin and the public domain or CC licences etc. What we really need is polish and the network effect, ie. the last 20%. Unfortunately we all know the last 20% sucks and we only do it if we're forced to do it.

Lerc

4 months ago

They could easily exist somewhere else, but they would not be found there

YouTube is the place where people find stuff, so if you want to be found, you have to be there. I posted something on this theme the other day. I would love for there to be a way for people to contribute things like this to the world while being supported so that they can do as much of it as they want.

I feel like YouTube is the worst video sharing platform with the exception of every other one.

I'm not sure of the solution. PAD files for videos? Some standard that lets people find videos no matter which service they are hosted on, letting the hosting and interface be provided by different entities. It would probably take regulatory action before YouTube supported anything like that.

ge96

4 months ago

Been finding indie music producers in the dream pop/shoegaze genre, seems better than Spotify recs

These are videos not YT music

nxobject

4 months ago

I applaud the author for doing this! A lot of "get your hands dirty" processor digital design tutorials end up using designs with a single microprogrammed control unit... which has no relation to how the last few decades of microarchitectures,

mrguyorama

4 months ago

Indeed. My CS degree program taught me Karnough maps and some other basics, and that was enough to build a simple microprocessor design myself (it sucked, I neglected to build a way to use immediate values in instructions so I had to build a hacky "set" instruction that just set a register to a 15 bit immediate)

But I mostly can't grok things like cache implementation, or branch prediction, or pipelines, or register renaming and out of order execution, or "store forwarding" and other necessary features.

The simulator programs I was using have instant/single cycle memory access, and the cpu had single cycle execution of all instructions so it wasn't really necessary, but still.

easygenes

4 months ago

I got lucky stumbling across this series a few years ago after just the first few videos were posted. Production value and pedagogy are excellent. Glad to see him following through all this time and getting to the heart of the matter recently.

reader9274

4 months ago

Ben Eater all day long over anyone else building a computer, sorry

WesBrownSQL

4 months ago

I don't think Ben would tell you to limit yourself. There are many fantastic people doing these kinds of things. James Sharman has been working on his system for years, and it is fantastic because he is also a programmer. https://www.youtube.com/@weirdboyjim

Dead_Lemon

4 months ago

This is the exact channel that came to mind when I saw the headline, his work is fantastic.

monocasa

4 months ago

There's no reason to have to choose.

Ben Eater is great, and Fabian is obviously inspired by him, so in a lot of ways this is simply complementary to Ben Eater's wonderful work.