Building A Computer Around A TTL CPU

[Bill’s] worked on his homebrew computer for almost a decade. He didn’t start with a Z80 processor like a lot of the projects we’ve seen, but instead build the CPU itself from 74-series TTL chips and a ridiculous amount of wire wrapping to connect it all.

The video after the break shows off the functionality. We love the front panel, which is packed with information but manages to remain organized and offers many convenient features. Our favorite is the ability to pause execution and scroll through the registers by spinning the dial. The clock signal has a variable speed which is selected by an internal DIP switch package that can be changed during a pause. It runs MINIX and has a library of programs, but perhaps most surprising is its ability to serve webpages.

Lately we’ve been interested in drilling down through program language abstractions to understand what is going on inside the silicon. This has given us new respect for those building processors from scratch. Think of it this way, if you actually need to build each instruction out of gates, you’ll be able to understand how those instructions work at the most fundamental level.


[Thanks Jamie]

26 thoughts on “Building A Computer Around A TTL CPU

  1. It truly is a remarkable feat to build a computer and actually get it working with full internet connectivity. I am currently logged in to it over telnet and trying its game “Adventure” ! The processing speed is quite noticeable though.

  2. I feel compelled to say “this has been around for a very long time,” but I love it so much. This is something I’ve always wanted to do.

    If anyone has hit the comment section without clicking the link, go back up and visit his site now! Bill is a pretty funny guy, the whole story is a good read, and there are lots of awesome photos.

  3. Reminds me of the old Altar 8800 that a couple friends and I built back in the late 70,s in the F14 Vast lab when I was stationed at PAX River TC. Looks like the 8800 has a successor! Just KEWL!

  4. Wow. We ‘built’ parts of CPUs in my one university class (to run code that was a variant of MIPS), using basic logic gates…and I thought that was kind of challenging. This? Wow. Though I’m more impressed by the software than the hardware — and I generally consider myself a ‘software guy’! I mean I get that it’s largely ported, but still…I wouldn’t even know where to begin.

  5. @Angmar

    Real purpose? Some guys spend time watching the clouds.

    I bet that if we appears with that “box” under his arm in some companies that will beat any curriculum. That is not something many of us can do.

  6. WOW! Hardware Pr0n! WOW!!

    It is cool… and nicely build.

    My only question is… is the air filter installed in reverse? I see airflow is going out of the case, or is this home brew computer also doubling as a air purifier?

    (Am I just discovered the Easter Egg?)

  7. Nice

    Personally my favorite DIY computers are the ones built out of relays. I just love that *clickity-clickity-click* as the relays process the instructions <3

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.