Since the 1970s, a common project has been to take a microprocessor and build a computer system on a breadboard or stripboard. Usually these machines have a familiar 8-bit processor such as a 6502 or Z80 because of their breadboard-friendly DIP packages, but there’s surprisingly little reason why some of the newer silicon can’t be treated in the same way. (FoxTech) is leading the way in this, making a breadboard computer using an 80486DX.
A 1990s-era 32-bit desktop CPU seems like unpromising territory for this application, but its architecture is surprisingly accessible. It needs a breakout board to gain access to its various lines, but beyond that it can be interfaced to in a very similar way to those earlier chips.
So far there are two videos in the series that we have placed below the break. The first presents the project and shows the basic layout. 486 running NOPs can produce a nice light show, but as he starts to show in the second video, it’s capable of more. The eventual goal is to have a simple but fully functional breadboard computer, so he starts by logic decoding the 32-bit bus on the 486 into the 8-bit bus he will use.
It’s fascinating to learn about how the 32-bit 486 handles its interface and deals with four bytes at a time, and we’re really looking forward to seeing this project develop. The 486 may be on life support here in 2023, but that doesn’t mean it can’t still get some love.
Thanks (Benny) for the tip!