If you are of a certain age you will remember logging into BBS (Bulletin Board Systems) through dial-up modems. During part of the of early BBS period I was stationed, in school or working overseas, so I would both do local BBS logins and carefully watching my pennies make quick connections from wherever I happened to be.
For a longtime I dragged around a Columbia VP Portable computer which I had hot-rodded with a better processor, loaded with memory including expansion “high” memory, and added storage. I had a huge stepdown transformer to tame the usual local 250vac-230-vac down to what the Columbia VP could work with. Old Computers has a page about this early “luggable” portable: https://www.old-computers.com/museum/computer.asp?st=1&c=889
My graduate thesis was done on this machine, with stacks of 5-1/4 floppys because you **never** depended on the hard disk without a backup or two.
But when I wasn’t working on school or business work, I would look at various BBS for anything I could learn.
Later I ran an Opus-CBCS FidoNet BBS for a number of years. Interesting as a hobby as electronically you met all sorts of people, including both the certifiably mental and the aggressive troll types. Quite an eye opener the mischief some folk get up to when they feel anonymous in a public place.
As a follow on to my various recent Raspberry Pi projects, I did a bit of a walk down an electronic nostalgia lane. One of the forums I had briefly participated in in the dial up days still exists as a web-drive community. I was pleased to find that they offered an ssh telenet access feature, which I have started exploring.
A quiet feature added to Windows 10 since that system was launched, is a ssh-client accessible through a Command Window. So you can get there from here without downloading additional software. I also used a Chromebook I had acquired as part of a charity project program design process first.
For those who haven’t done this sort of thing, the high level overview is you open a Terminal/Console/Command window with access to the worldwide web, then run a either a command or a program which starts an ssh (see: https://infogalactic.com/info/Secure_Shell ) session. Next you identify and authenticate with your username and password. Then you are in.
At least that was the way I could do a legacy ssh telnet access to the community.
BTW old school BBS systems often had a new-user routine, where you could obtain or apply for credentials.
I used https://www.telnetbbsguide.com/ to poke around at others. Kind of neat site as it has the ability to act as a Terminal/Console/Command Window for you.
One site I poked around at was one run by Rich Lawrence KB2MOB:
Their bog is at: https://rfgeeks.wordpress.com
Back in the day I had a series of modems, culminating with the US Robotics Courier V.Everything V.90 at the end of my original BBS involvement. From 1984-1988 I also had a British Telecom Prestel terminal, which in addition to basic email and BSS access also gave me my own telex number and allowed for a wide variety of online shopping. In the day I also did some of my banking with Bank of Scotland over the Prestel system. http://iml.jou.ufl.edu/carlson/History/Prestel.htm
In these various legacy systems the user commands are all over the place, ranging from a “. on blank line plus a carriage return” to the WordStar like “ctrl-K, ctrl-D” to save and end an editing session.
Pretty neat trip down memory lane….