Recently, I was inspired by Ben Eater’s YouTube serices where he built a CPU using 7400 logic chips on breadboards. I had thoughts of doing the same, but I wanted it to albe to demo well to kids at Maker Faires, play games on a VGA display using serial game controllers, for example. Well as the idea grew, the design was all of a sudden going to take 20 breadboards and probably more. That’s like $200 worth of boards.
Meanwhile, I had seen articles on how hobbyists were building soft CPUs that did things like emulate the venerable Commodore Amiga. It’s really only recently that FPGA boards for the hobbyist market are starting to be powerful enough and cheap enough, and yes, are well under the $200 I’d have to spend on breadboards alone.
As I worked through the idea, I was energized. What a project it would be to build a computer from the logic gates on up to a working gaming rig. There’s lots of that going on in the 8-bit world from the 80’s. I’m more interested in the era of the early 90’s. I had a Commodore Amiga and I truely thought it was far better than the PC’s of the time. The Motorola 68000 has a much cleaner architecture than the 8086. The Amiga had a color GUI for crying out loud.
So I’m really curious what a m68k machine, of the early 90’s that rivaled the i486 that ran DOOM and changed the gaming world, would have ran DOOM and changed the gaming world. So that’s the plan. To build it and share it’s design as an education platform so others can see and learn how things we’re built back then, pre Windows 95 when the industry lost it’s pioneer spirit. It was so exciting back when the Apple II, TRS-80, Commodore 64 and so many other innovative machines fought tooth and nail for the minds of users and developers. What if that kept going into the 90’s?
I recently bought a ULX3S FPGA board from Crowd Supply produced by a group in Croatia. It has every I/O I could want to build my dream 90’s machine, plus some goodies that allow it to use modern peripherals, especially USB for keyboard and game controllers, HDMI for display output, and a slot for an SD card for storage. And not only that, they strapped an ESP32 module onto it to give it Wifi and Bluetooth. And all for what I was going to spend on my little breadboard computer. I can’t wait to get started.