Back in those days, you used your dial-up MODEM to call into the BBS Server. The BBS had a local phone number, because it was typically one guy's DOS-based PC running of his house. Often there were only a few (or even one) phone lines available, so you got lots of busy signals. Once logged in, you used a simple number-based menuing system to leave messages or download/upload files. It was usually all text-base, there were no graphics except for simple ASCII art. Some BBS's were free, and sometimes you had to pay to be a member.
 Roberta Williams
Roberta Williams was video game designer during the 1980's and 1990's. Her perhaps best known series is King's Quest, an early graphical adventure. She also worked on (and was on the cover of) a text-based softporn adventure that inspired the Lesiure Suit Larry series. She even has a fanclub.