I have a reasonable number of meetings that involve people transmitting data at suboptimal baud rates. Doodling has always been a valuable way to provide some mental exercise and increase my retention of the important bits.

I have always tended towards doing designs during these idle times, and in particular I like designing microprocessors. I find that post-it notes are a good way to organize hierarchical design, and makes it easy to pick up a design months later. Sometimes I’ll do something novel like a single instruction design (‘mov’ obviously), something like a 128-bit VLIW, a yet another MIPS knock off, or in this case a very compact 8 bit design that can be implemented in a reasonable number of old school 74 series gates. Sometimes I’ll just write out stuff in VHDL, but doing old school Kmaps has its place.

It is really simple stuff, but I find it very relaxing and calming.

What do your doodle designs do?