The Arduino Nano itself is the most basic and oldest of the group, and just like its many iterations, it's designed to work primarily with breadboards, making it a great tool for prototyping.

You’d probably get something like [ElectroBoy]’s 8051-based Arduino Uno. Close-up shot of the 87C752, an 8051 with EPROM. The Arduino Uno-compatible board has an MCS-51 ...