Fun on Old IMB Mainframes
AT Uni we ran a couple of old IBM 360's but they didn't run TSO or CICS, they ran the Michigan Terminal System MTS. This was an OS designed for connecting a whole load of dumb terminals to a central processor and act as a timeshare system.
That's all well and good, but they gave us access to the OS source code. Computer Students, beer at 17p a Pint, time on our hands, and source code: What could go wrong?
What went wrong was when we found an undocumented command that allowed us to send messages to the central operators console, an IBM 3270 connected directly to the processor. So, a bit of experimentation with IBM control characters, and we sent the commands to clear the Ops console and write four words to it: BIG BROTHER IS WATCHING.
Who knew that the operators were unionised, and in a dispute with the University? They just got up and walked out.
And we got our knuckles severely wrapped for that jape!