Octavus is an 8-bit computer made in the game/software called Virtual Circuit Board. This project is BY FAR not a professional computer as it was designed not by a professional hardware guru but me, a guy who mostly does software. My goal was to make this computer quite fast (in terms of clock cycles per instruction) which I believe I achieved. The project is not finished yet: Currently only a few instructions work. I will fix this as soon as I have some spare time. I am aware that the following systems are probably poorly designed:
- The instruction decoder
- The flag system
Currently I do not plan to change this, as this is again an amateur project and not a professional one. Despite that fact, the project works flawlessly. Note that the buffers after the clocks are used to slow down the system, as every gate requires 1 tick to process the incoming data and the clock sends pulse every 2nd tick. I also used them as one-way diodes.
Do note, that the separate files (which contain the modules one-by-one) might be outdated!
It's a beautiful summer day. In the evening I opened up steam to play some Hackmud, a scripting game you should definitely check out! I update my recommended list and a game called Virtual Circuit Board pops up. The demo-images definitely caught my attention: A bunch of different "circuit boards" built up from logical gates, basically George Boole's game of life. Well I've definitely seen some identical games/softwares, but I never had the time to do real hardware. I mean sure, I used to play around with Arduino and Raspberry, but I only made temporary projects, like a meteorology station or a basic handheld gaming console. But at the time I was programming in x86 bare-metal assembly (AND in 32-bit protected mode) so I definitely needed something to relax. And this game seemed ideal. I would still stick to the "theme" of my main project (the one in x86 assembly) but in my free time I could make something fun in VCB. So that's the story how I laid my hands on this wonderful game...
Well in the first 1 or 2 hours I played around in VCB just to see how the game works. But well, the game itself is pretty simple: just some logic gates, colored wires and a few other components like latches. So my first project was basically an ALU. I wanted to see if I could still build one. Well with the help of Google I managed to make the more advanced ALU. Maybe I could have remembered the adding part of the ALU, but the ALU blueprint I followed is far more enhanced and a far more compact than my would have been. After successfully adding 2 1 byte values together I thought: "Heck, let's just create an 8-bit computer." And I guess the rest is history...
I had no former experience in building an 8-bit computer. Most of my knowledge about them comes from a YouTuber called Ben Eater. You should definitely check out his channel. He is a professional in hardware, and even pretty complex topics are explained exceptionally well. So before this projected I watched some of his videos just out of sheer curiosity, but I kinda felt, I wanna do this computer by my own, even if that means I won't be able to design it the way it's described by professionals. But as this project was mainly a relaxing side-project, I didn't really care and to be honest I don't regret that decision.
After a few weeks of designing the computer, I'm at the goal line. Sadly I won't have those side-hours in the near future which I had, thus I can't really finish Octavus :(. I'm planning to finish this project as soon as possible, but I really don't know when it will be finished. After all, the journey is the matters, not the destination...
Making this computer was definitely something I would recommend to everyone especially the ones who are working in software field to, you know, shake things a little bit up ;p.
If you want to try out Octavus yourself, you can import it with VCB anytime!