Terminal Emulation - What Is It? Years ago, before the PC
revolution, people used terminals to interact directly with
computers (they also submitted batch jobs on decks of punched
cards or rolls of paper tape, but that's another story). A
terminal has a keyboard, a display, and a communication port.
The earliest terminals were Teletypes (in wide use since the
late 1920s), a kind of communicating typewriter. (What's a
typewriter?) By the mid-1970s, most terminals had video displays
(like a PC monitor) instead of printing on paper. Typically many
terminals were connected to one large computer, which all the
users shared; this was called timesharing. Well-known
timesharing systems included MULTICS, UNIX, RSTS/E, TOPS-10,
TENEX, TOPS-20, AOS/VS, VMS, VOS, VM/CMS, and TSO; some of these
are long gone, others are still popular today. Video terminals
did more than simply display incoming letters, digits, and
punctuation, as a typewriter would. They also included
formatting capabilities allowing for host-directed cur