Wired: Where Old Macs Go Off to Thrive. I can’t go any further than this picture of an old SE/30 upgraded with a G3 running OS X on a monochrome screen.
The SE/30 was my first computer (if you don’t count the family’s Apple //c). We had it tricked out with 5 MB of RAM and a 40 MB hard drive. I learned how to do desktop publishing, Excel macro programming, telnet, and Kermit file transfer(!) on that little machine.