weirdest UI ever
One thing you should know, if you'd never used it, was that the ITS "shell" was a binary debugger.
You'd login by typing "mlk$u" where "mlk" was your user name, and "$" was the Escape character. No password was required (or even allowed; thanks RMS). You could then type something like "4/" and see what's in location 4 (which was a register on the PDP-10). There were ways of running commands like macsyma, too (":macsyma", i.e. put a ":" in front of the command line).
Even stranger, you could type $$^R, and it would unprotect the OS, so that you could patch the running kernel from your shell.
I am not making any of this up.
Biting the hand that feeds IT
