Scratch-Built 8-bit Retro Computer
By James Grahame
We featured Matt Sarnoff's Terminalscope earlier this year. Now he's back with a complete system.
He writes: "I've designed my own 8-bit computer, using the somewhat obscure Motorola 6809 processor, wired it all up by hand, and wrote the operating system, drivers, and the rest of the software, all in assembly language. It runs at a blazing 2 MHz, has a spacious 512KB of RAM, and can read files and run programs from a CompactFlash card. So far, user interaction is through a serial cable connected to a PC.
Now that's not too bad, but I also went ahead and added vintage sound and video chips I bought on eBay. I stuck in a TMS9918A video chip (used in the ColecoVision, TI-99/4a, and more) and a YM2149 sound chip (used in the Atari ST, the ZX Spectrum, etc.) I've written a chiptune player and a couple graphical demos; my next steps are to actually write some games, and eventually get it hooked up to the internet..."