Having completed building my version of Ben Eater's 8-bit breadboard computer nearly a year ago, building my own Apple 1 clone, building and looking into the inner workings of the Gigatron kit and studying the book Digital Computer Electronics it is finally time to design and build my own TTL computer from scratch!
The main goal is to learn how to do this and see if I can actually accomplish this build. The computer itself must be usable as a learning tool for people that want to learn about CPU architecture.
That means lots of blinking lights and switches!
The plan is to build an 8-bit computer with TTL logic chips that supports 64 kB of memory and a clock speed up to 1 MHz. The first project log on Architecture describes the features in a bit more detail.
All the circuits are (being) designed in KiCad and then prototype'd on breadboards. When the whole thing has come to live and the entire design has been proven to work, I'll design a PCB for it as well.
I will try to regularly update the project log with the status of the project.
At the moment I'm still in the design phase, although a lot has taken shape by now:
- I worked out an architecture (see project log)
- Worked out the majority of instructions, including their T-states (coming to project log once tested)
- Worked out several of the circuits (coming to project log as modules are tested)
- Built the clock module and one register on breadboard (coming to project log soon)
- Keeping track of everything in a Github repository.