[Carl] wanted to prototype his circuits quickly using printed circuit boards. He picked up a Bantam Tools Desktop PCB Mill and made a video about the results. His first attempt wasn’t perfect ...

We see a fair few PCB mills, some 3D printed, and some not. Here’s a nice one that fits in that former category. Milling PCBs is quite a good solution for the rapid prototyping of electronics.

While this prototype still wasn't a full-fledged single-board computer ... all on a credit card-sized PCB. In December 2011, ...