You may have seen Grant Searle's Multicomp project - an inexpensive Altera FPGA board acting as a variety of 8-bit micros. You can hook up a 128k SRAM and configure a CP/M machine, all for about $50, which is what Steve Mansfield-Devine did:





Steve was following in the footsteps of Oscar Vermeulen.

"As I have a weakness for such devices (from where I sit, I can point to seven Raspberry Pi computers, some inside completed projects, three BeagleBones and countless Arduinos), I knew I would have to do this."


Wow! This poor man is even more obsessed than the rest of us!

I don't know why he says that Windows is the "only option you get with Quartus" (he prefers to use Mac or Linux). It's available for Linux, I have several versions installed, including the version recommended by Grant Searle for use with Cyclone II that was mentioned. And the part about getting a free license key was also confusing - there is no license, it's just the web edition of Quartus II to install and run.
But the article was a nice read. The mechanical part (boxes and holes etc.) is what I struggle the most with in such projects, I can only watch with envy..

The mechanical part can indeed be daunting; and what's shown above is very, very simple compared to requirements for some other computers that need portability, a display, keypad, places to plug in modules that will get changed for various projects, and lots of connectors. (I'm fighting through that myself at the moment.)