Here’s my experience with both. It was the late 70’s and early 80’s. Ma Bell had not yet completed their transition to out of band signaling, so in-band signaling was still very common. Friend of mine had an Apple II with a Novation CAT modem with a little program called CatFer. CatFer could generate all the MF tones including KP (2600Hz) etc.

Spent lots of time there playing around the network, calling Regional Network Operations Centers (RNOC’s) after relaying the call through several points around the world was quite the trip. Even got to talk to Draper on a conference or two.

I also figured out the algorithm that then Sprint was using for it’s codes for long distance service. So many calls were made gratis via Sprint’s network because of me.

Hacking was a bit different. I did procure a set of user id’s and passwords for the IBM 370 at Brown University when I was a high school student, which I then gave to friends who knew the DOS/VSE running on said system. When they managed to get that 370 to do a core dump, it was major shit since one of those friends father was a Providence police detective. Ooops.

My deal was my first shot at college on their Digital PDP-11/70. Figured out how to get the keys to the kingdom by writing a login simulator and running it on the operator console. Under RSTS/E you could allocate devices including the system console, so that’s precisely what we did. The only access to the 370 on campus was via punch cards which I had to use for a PL/I class, so it didn’t have that immediacy.

Friend of mine and I had a complete email and chat system running on that PDP-11/70.

Well, one night the email system glitched and caused a core dump of the 11/70. I get called into the director of info systems office and had my access revoked. Oh well, didn’t matter, I still had every account name and password on the system as well as the dialup numbers for the system. We fixed the email program and to my knowledge that baby was running for a couple years after I left.