CRC

I watched Ben Eater’s videos How do CRCs work? and Checksums and Hamming distance (the full course is Learn about error detection) then found the Wikipedia page: Cyclic redundancy check.

Also of interest:

Forth

I’m reading Discover FORTH: Learning and Programming the FORTH Language and I have a growing interest in the programming language Forth. Here are a few resources:

And some other books on Forth:

And there are a heap of Forth books by Juergen Pintaske.