We had a classroom full of networked BBC Micros in high school. I remember that the teacher had the big one with the floppy drives (BBC Master System?) which acted as a fileserver for the smaller beebs with less RAM.
One of the students in the upper year levels gave a friend and I some POKE style commands that could be used to remotely reset the fileserver. We got immense joy out of resetting the fileserver when the teacher had his back turned away from us since it would prevent disk access for the entire class.
We would then chuckle to ourselves quietly while all the other students complained to the teacher that they couldn't load/save files over the network for a minute or two. The poor teacher became more and more exasperated, but never understood or figured out what was going on. This was very funny to my friend and I, being the immature 13 year olds that we were.
We had a classroom like yours, with BBC Micros and special BBC fileserver computer of some kind, with the important school stuff on it.
My fun command was a one-liner that repeatedly remote-PEEKed the server's keyboard buffer memory and displayed it on one of the classroom computers.
One day, when the teacher went over to the special server corner to type in the server password, I quickly entered this one-liner into a computer in the main area, and lo as teacher typed the password thinking it was all very private and special, it appeared key by key on my screen. Of course all the children were watching my screen, "hey watch this...".
Yes, the folly of youth :-)
That got me permanently banned from the computer room. I didn't expect that, I thought we'd all laugh it off and tell me not to do it again. Ironically, knowing more about computers than anyone else in the school, I wasn't allowed to study computers at school or use them.
Still won a programming competition there anyway, for making a pretty demo to tell a story :-)
Oh you too! My ban came from discovering where the station number (the 8 bit number uniquely identifying each BBC Micro on the Econet network - like a MAC address) was stored in memory. I did this by the obvious technique of searching memory for this number on several machines and comparing the addresses - it was address 3361. Then I found that by changing this you could impersonate the credentials of the person logged in to the other machine, although it worked better if you also had a co-conspirator turn off their machine at the same time.
The other hack which possibly contributed was writing a kind of "broadcast NOTIFY" that sent your keystrokes to all of the other machines on the network, allowing the user to remote control all the things. The service manual I just found online says that *NOTIFY is a dangerous command which the operator might want to remove - but in fact there was a system call which did the same thing and I used that instead.
I recall the hex address being D22 (so 3362) although it's been 30-cough-something years so I could be misremembering.
I built a full-on remote hacking utility that got to the point where it would download the remote victim's RAM, upload the infamous laugh sound, play it, then restore the RAM so the victim was - usually - back to before they got freaked out.
A small group of us built a multi-screen text scrolling and image display sequencing tool for the various school open days. I still recall the nervous look on the teacher's face as we deconstructed the computer lab to get all the Microvitec Cub's lined up! Those were fun times.
I got banned a little later (in the 90s) for writing a QBasic "chat app" that worked across the school network by way of a public NetWare shared drive. I didn't even take IT as a GCSE option because having arguments with teachers who thought a PC's base unit was "a CPU" didn't seem worth it, and my disdain for "IT" (as opposed to software engineering) unfairly remains to this day :-D
Bizarrely, at University in the UK, we had a student TV station and it used a BBC Micro for caption generation. My ZX Spectrum had a microdrive attached (the new hotness, flaky as hell but much much faster than loading from tape) I remember writing something that let the Spectrum act as a fileserver for the BBC micro over its serial port. Good times.
Similar story, just replace the BBC with another national project, the ABC 800 Z80 computer. I would change the source code of programming examples on “the Winchester” which was a huge hard drive on a cart connected to the teachers master computer.
One of the students in the upper year levels gave a friend and I some POKE style commands that could be used to remotely reset the fileserver. We got immense joy out of resetting the fileserver when the teacher had his back turned away from us since it would prevent disk access for the entire class.
We would then chuckle to ourselves quietly while all the other students complained to the teacher that they couldn't load/save files over the network for a minute or two. The poor teacher became more and more exasperated, but never understood or figured out what was going on. This was very funny to my friend and I, being the immature 13 year olds that we were.