After you log in, you will be presented with a screen looking something like this:
** GREX NEWMENU SYSTEM ** Copyright 1999, Michelangelo Giansiracusa B) BBS (very, very cool!!) Z) View BBS introductory info D) Donations to Grex X) Lynx (textual WWW browser) C) Change Password/Other Stuff N) Send a 'telegram' to a user T) Talk live to a user - write A) Answer (Answer write) H) Talk to a (live) Helper W) Who (who is on the system) V) View daily message I) Information about a user M) Mail (Check your mail) S) Send Mail F) File Utilities Menu P) Party (multi-user chat) Menu U) Basic Utilities Menu G) Games Menu O) Other Menus R) Run a UNIX Program Y) Lock your terminal L) Log off from Grex E) Exit menu system Command (if unsure type 'HELP'):You just enter the one-letter commands, which will execute the commands, or move you to similar-looking sub-menus with additional commands. For example, the "B" command puts you into the bbs system (just where you'd start out with if you had selected the "bbs" shell), and the "E" command exits the menu system, leaving you in the Unix "csh" shell. The menu will be redisplayed after every command.
Note that you can also execute standard unix commands from the menu by preceeding them with a ! symbol. So you can do ``!ls -las'' to list your file (or you can just use the ``List Files'' menu option on the ``File Utilities'' submenu if you don't want to learn all these obscure Unixisms).