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.
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
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.
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 😅
|1||8-way DIL switch||RS Components||1.51|
|1||DIP switch SPST||RS Components||1.22|
|50||Red LED 5mm||RS Components||14.88|
|20||Green LED 5mm||RS Components||3.70|
|10||Yellow LED 5mm||RS Components||2.42|
|25||Blue LED 5mm||RS Components||10.32|
|3||SPDT Slide Switch||Farnell||4.36|
|4||Seven Segment Display||Farnell||4.34|
|2||USB 2.0 2m cable||Amazon||4.29|
|1||5A USB plug adapter||Amazon||7.64|
|1||74F189 64-Bit RAM||eBay||5.99|
|3||16K CMOS Parallel EEPROM||eBay||19.11|
|10||2 Pin PCB terminal block||eBay||2.49|
|3||3 pin SPDT Slide Switch||eBay||2.05|
|100||22awg Hook up Wire||eBay||17.25|
|15||K&H RH-21 840 Breadboard||Rapid||126.36|
|100||1K 0.5W Resistor||Rapid||1.56|
|100||10K 0.25W Resistor||Rapid||1.05|
|100||100K 0.25W Resistor||Rapid||1.05|
|100||470R 0.25W Resistor||Rapid||1.05|
|100||1M 0.25W Resistor||Rapid||1.05|
|1||Finger Adjust Pot||Rapid||0.94|
|1||Wera PH0 screwdriver||Rapid||3.01|
|1||Wera PH1 screwdriver||Rapid||3.48|
|1||Wera 0.18 Slotted Screwdriver||Rapid||3.23|
|1||Bugari Needle Pliers||Rapid||13.79|
|1||Bugari Blade Cutters||Rapid||13.09|
|1||Anvil Wire Stripper||Rapid||5.29|
|1||Arduino Nano Evaluation Board||Farnell||17.28|
|1||AN8008 Digital Multimeter||Amazon||24.05|
|1||120pc Jumper Wire Cable Set||Amazon||3.49|
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.
The project's next step is to build the first part of the computer, the clock module.