[andrewshatnyy]

Those diagrams are badass! Anyone knows what was used to make em?

[arnarbi]

Not OP, but I like https://monodraw.helftone.com/

There are a few online variants, e.g. http://asciiflow.com/ and https://textik.com/

For extra credit use these fonts: https://int10h.org/oldschool-pc-fonts/fontlist/