I write a book about old computers. Oh, sorry: I mean "vintage computers" from 80's. My primary goal is to show how one can build a 8bit computer from scratch. It means: how to set up a CPU, how to connect memories, how to connect peripheral chips, and why to connect...Show me the computers!
The simplest construction you can find.
You can build a kit and solder it
Hack. Upgrade. Publish.
Made by an old computer lover for old computer lovers...
It took me like an hour to get it working (including all soldering and testing - everything worked just
right on first try). The documentation is really retro, as I remember from that era. You get simple monitor program already installed in EEPROM together with two modules, one just simple test, the other simple tiny BASIC (2.5kB), so you can start playing with it as soon, as you finish the instalation (by using any computer with USB as simple serial terminal - LOL 2GHz 16GB RAM laptop as dumb I/O device for 2MHz 64kB RAM computer, but it works, so what :)
The documentation on github is really good - datasheets for each IC, handbook explaining CPU, electrical schema as PDF as well as Eagle files ... everything you need to lear and having fun with it :)
So sumary: Nice, easy to build, works from first moment, much fun, lot of power and a lot of education - I heartfully recomend that :)