At my high school, our CS lab had two Teletype terminals that were connected to a remote HP minicomputer over 110 baud (that's 10 chars/sec) acoustic couplers/modems. You had to dial the computer's number then put the handset into a foam-lined wooden box and close the lid. To upload a game, like Star Trek, we punched the game onto paper tape while not connected, then fed the paper tape back through once we got connected. Getting a connection could take 10-15 minutes of manually redialing after getting a busy signal because the service was so oversubscribed.

Our "high speed" terminal was a 300 baud (30 CPS) CRT.

These 3 terminals were shared by about 15 kids per class.