Path: utzoo!attcan!uunet!nadc.nadc.navy.mil!prindle From: prindle@nadc.nadc.navy.mil (Frank Prindle) Newsgroups: comp.sys.cbm Subject: Re: Desterm Question! (answerback) Message-ID: Date: 11 Oct 90 11:51:13 GMT Sender: prindle@NADC.NADC.NAVY.MIL Lines: 20 Answerback is one of those historical dinosaurs which persists to this day for compatibility. In olden days of telecomputing when terminals were largely mechanical and ran at the blinding speed of 10 characters/second or less, each terminal was pre-programmed (by The Phone Company, since they held a monopoly on telecom equipment back then) to transmit its phone number or some other identification whenever it received an ASCII ENQ (^E, enquiry) character (in pre-ASCII days, this was called WRU - i.e. Who aRe yoU?). The purpose was so that the receiver of a call could unconditionally tell who called (The Phone Company always were a suspicious lot). Because this code remains reserved for this function in the current standards for ASCII encoding, terminals (and terminal emulators) to this day must support answerback, though we are now free (thanks Carterphone!) to program any sort of cute saying we want in the answerback message. Since its original purpose is totally destroyed, it is typically totally ignored. But you can still make any ANSI standard terminal transmit its answerback by sending it a ^E if you can think of any practical purpose for it! End history lesson, Frank Prindle Prindle@NADC.navy.mil