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.
Let's telnet to an ITS machine. ITS will greet you:
MIT Artificial Intelligence Lab PDP-10
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
Welcome to AI!
AI ITS.1647. DDT.1545.
TTY 11
You're all alone, Fair share = 99%
^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).