As I stated, I used Archie, Gopher and IRC.. and as I just remembered EW-Too chat prgrams and MUDs/MUSHes/Etc... and was connecting to them directly from a shell account.... so by your definition that falls under ISP.
OK, I guess I didn't make it clear enough.
If you can send IP packets over your dialup connection and have them routed onto the Internet, and have IP packets from the Internet routed to your machine over the dialup connection, you're dialed into an ISP.
If you have to dial up a host and log in to getty over that dialup connection, then you're dialed up to a UNIX shell service provider, not an ISP, even if the UNIX host you've logged into happens to be connected to the Internet.
If a UUCP program on your machine has to dial up a host and log into a UUCP account over that dialup connection, then you're dialed up to a UUCP service provider, not an ISP, even if the host you're connecting to via UUCP can route emails to the Internet.
So unless you were using Archie and Gopher and IRC clients running on your machine at home, with those clients sending IP packets out over a SLIP connection and receiving IP packets from that SLIP connection, you were not dialing into an ISP.