Sam's ITS primer

This document aims at teaching you the basic concepts of ITS from a user's point of view and a few useful commands to be able to get your job done on an ITS system. All suggestions and comments are welcome.

Note: ^Z means Control-Z, for any character Z, and $ is altmode, or escape on modern keyboards, unless specifically noted otherwise.

Warning: this primer is not finished yet.

First steps

Let's telnet to an ITS machine. ITS will greet you:
MIT Artificial Intelligence Lab PDP-10
Welcome to AI!

AI ITS.1647. DDT.1545.
TTY 11
You're all alone, Fair share = 99%

If you've telneted to the machine, the tty will be active. Otherwise (if you're logging at the console, for instance), it may not be (that, is characters you type do not appear). In that case, press ^Z, to wake up the tty. ^Z is one of the few commands directly interpreted by the monitor (kernel, in modern OS language).
The first thing to say is that's it. You are using the system. Indeed, ITS doesn't need you to login or anything to start using the system (unless somone has setup an access control program, like PANDA). ITS does have a concept of users, and of logging in, though, and in fact, you are logged in as a user, probably called ___n where n is a 3-digit number.
However, I guess you'd rather want to be logged as a user with a more meaningful name. So, type :LOGIN user at the tty, where user is at most 6 letters long (ITS stores usernames, and lots of other string data in SIXBIT format, where each character holds in 6 bits. Since a word on the PDP-10 is 36 bits, it's convenient to allow up to 6 characters). This will log you in and load HACTRN (HACTRN is just the name used for DDT, the debugger, when at the root of a process tree; in Unix world, you'd say it's the shell).

Valid XHTML 1.0! Viewable With Any Browser Powered by GNU Emacs