Build an 8-bit computer from scratch (2016)

Posted by jcartw 3/31/2025

Build an 8-bit computer from scratch (2016)(eater.net)

398 points | 62 commentspage 3

DeathArrow 4/4/2025|

I wonder how would it compare to an old 8 bit CPU like 6502 or Z80.

compiler-guy 4/4/2025|

It is vastly underpowered and has a huge bill of materials compared to those chips. It only supports 16 bytes of memory, has an impoverished instruction set, is slow as molasses, and tends to be very flaky.

Even as a pure-ttl building exercise, it trades off efficiency and usefulness in favor of understandability and fancy blinking-lights so you can see what is happening.

It is useful only for toy programs at the most.

But as a learning exercise it is absolutely first rate. 10/10 would recommend.

Pixelious 4/4/2025||

Love me some "Ben Eater does this and crushes it"

gsibble 4/4/2025||

I built this kit. It was a lot of fun but very tedious. I also have a computer engineering degree so I didn't really learn much. It was fun to show to people though.

If you don't understand what a register is for example though, OH MAN. You'll love this!

asdefghyk 4/4/2025||

Another "interesting" thing to do with this project is build it in a "Digital Logic Simulator"

userbinator 4/4/2025||

You need to enable JavaScript to view this site.

Nope. Why does this page need to be an interactive webapp? Ideally it'd be viewable on the 8-bit computer you built from scratch too.

edoceo 4/4/2025|

Yo. It's 2025. We don't need to rage at JS, a little sprinkling is OK.

Also, can one do a TCP stack in 8 bits?

userbinator 4/4/2025||

a little sprinkling is OK.

This isn't progressive enhancement, the page is completley unreadable without running JS. It rather irks me that someone who clearly knows about the basics of computing would do such a thing.

Also, can one do a TCP stack in 8 bits?

Yes. Lots of low-end IoT devices have an 8-bit MCU. Also, this:

https://www.c64-wiki.com/wiki/Contiki

mechanicalpulse 4/4/2025||

The site was assembled using webpack and at least one element has a `data-react-helmet` attribute, so my guess is it's a React or React derivative such as Next.js. You're right -- it's not progressive enhancement and it's not necessary to present a simple tutorial.

Maybe there are other reasons, though? Maybe Ben wanted to learn the framework? Maybe Ben wanted to integrate a storefront and a comment section -- which he has done via Shopify and Disqus -- and his choice of framework made that easy due to the existence of official React libraries from both vendors? Maybe Ben's using cloud-native serverless deployment tools alongside his React application because some of the derivative frameworks like Next.js do really well at minifying, compressing, caching, and serving only the content that's needed?

I can understand the purist argument -- I really can, especially from a security standpoint given what we've learned in the past few years about cache-timing side-channel attacks -- but is it possible that Ben is simply a fan of learning and he's as excited about building a web application in React as he is about building an 8-bit computer from scratch?

charcircuit 4/4/2025||

It would be more efficient to implement this with an FPGA. An FPGA will scale with more complex designs.

revskill 4/4/2025|

The finbonacci on this computer should be faster than rust.