Intro

Welcome to the first blog post in my Building an 8-bit Computer series. In these posts, I will be documenting my journey of learning the fundamentals of computing through building Ben Eater's 8-bit computer from scratch. This blog is a work in progress and mainly for retrospection on the interesting things I learn along the way.

In this post, I will be going through why I decided to build an 8-bit computer and the procurement of components required to get started.

What is Ben Eater's 8-bit computer?

Ben Eater's 8-bit computer is a video series documenting Ben Eater project to build a computer built from scratch on breadboards using only simple logic gates.

https://eater.net/8bit/

If you are thinking of doing this yourself, Ben Eater seems to have a cult following on Reddit (which hopefully I will be part of soon). I would recommend checking out this community here: r/beneater

Why?

I've been interested in electronics and computers from a young age, having recently started a career as a software developer in Ruby and JavaScript stacks, both high-level langagues. However, since learning the basics of how a CPU works in the Introduction to Computing module in my Mechanical Engineering degree, I have been curious about how computers work from the ground up.

Having no experience in low-level languages, I know there is a significant gap in my understanding of computer programming. Learning computing at a lower level would improve my knowledge of the languages I work in and possibly open up new opportunities for hobbies and work.

I have a basic understanding of electronics, such as the physics of circuits and how semiconductors and gates work. But any further than that, it's a black hole.

I discovered Ben Eater through YouTube recommending his excellent video on binarary adition using logic gates, it piqued my interest, and I started exploring his channel and website. From there, I saw the 8-bit computer project and thought I might as well jump in at the deep end and force myself to get the deeper understanding I need. It's also fun learning a new technology field, particularly one where it provides the potential to create almost anything.

I intend to research and understand how each component works throughout the project, so it'll probably take a lot longer than I'd expect if it was just plugging components. I'll keep note of how long it takes and let you know in the conclusion post.

Procurement

Since I live in the UK, I decided not to buy the package Ben Eater sells on his site due to import tax and shipping, so I went about going through the parts list and buying chips.

It took about 4 hours to purchase all of the components, some of which seemed hard/impossible to get locally in the UK. Regarding chip numbers, commonly, I found the correct part number but with suffixes such as an N after it. I'm not sure if this means anything yet. I briefly read the datasheets (which, after watching a couple of videos, seem very important), and I am confident I will be able to wire it up correctly if I understand the logic of the chip does and its spec. However, I'll likely look back on this statement and cringe at how wrong I was 😅

Computer Parts

Tools

As you can see when comparing to the required list of components, many companies had minimum purchase quantities, which was a downside to ordering them myself. The upside is that this does give some redundancy for broken components and supplies any future projects.

Total for components came to £304.73
Total for tools came to £86.71

For a very basic computer, this might seem like a lot of money. I did get a couple of comments from the missus asking me what more it could do than a £5 calculator while costing the same amount as a low-end laptop. To that, the only answer I have at the time is "it's a hobby" and "it might teach me more about how computers work". Hopefully, I'll learn a lot and have some fun.

What's Next

The project's next step is to build the first part of the computer, the clock module.