[genmud]

You should look at atiny10s too, they have a 6 pin and through hole version and you can use them without a crystal.

I have thought about making a design for one and doing a series where we make an assembler in python, where it's an exercise in writing a parser to output the binary assembly for use in a simple micro like the atiny. They have limited registers and instruction set, so would be a good way to help people understand what is happening.