These are computer-related practical jokes played by an old acquaintence years ago at a nameless university in Northern California.

These are computer-related practical jokes played by an old
acquaintence years ago at a nameless university in Northern
California. He wisened up and stopped playing them when the
various administrations of the computer centers found out who
it was. Sometimes I simply could not believe that he would do
things like this.

The first one was probably the worst. The undergraduate computer
center was being connected to a large terminal lab across campus via
a long line across campus. This had taken the technical folks who
worked at the computer center months of planning, pulling cables,
attaching lines, reconfiguring the system, and so forth.

It was at about this time that Jack (not his real name), wrote a
program called "GARB" (short for "Garbage") This program sat in the
background running at low priority. It would choose a random interval,
sometimes seconds, sometimes minutes, sleep for that interval, and
then wakeup. At that point, it would choose a random ASCII character
and then choose a random terminal on that computer and send the character
to the terminal. Then it would loop back into its sleep mode until the
next time it woke up.

The administration and technical people spent weeks wondering why
their attempts at connecting cross-campus cables were causing spurious
data across existing lines, as well as the lines that had been connected.
They had people out there with the elaborate technical equipment trying
to trace down the source of the "noise" that was polluting the terminal
lines with stray characters.

Quite a while later, they did indeed discover the problem and confronted
Jack. I'm not sure what happened after that.

Another thing Jack did, before that, was write a program called "GOD".
It would patch the running monitor and actually insert a jump into the
code that performed the logout-job function within the monitor. The
jump simply took control of the monitor to a patch-area elsewhere
within memory where a simple comparison took place to see if the
logout being requested was of any jobs belonging to Jack. If so, it
simply did a no-op, with an appropriate return-condition indicating
success (so that the calling program which initiated the system call
would not know the job had not been logged out). This program, "GOD"
most came in handy to Jack during the wee morning hours when few
people used the system but the proverbial "wheel wars" occurred, in
which enabled superusers with privileges attempted to conquer each other
in various ways.

Needless to say, none of the above behavior is tolerated by the
administration any more, with good reason.