wall@fortune.UUCP (11/03/83)
DTR is most certainly a handshake signal, and just as valid a one as CTS. No one is going to argue that CD (or DCD as most people refer to it) has anything to do with handshake. Where was I? Oh, yes; it is strictly a matter of perspective. If you are a terminal (DTE for you fanatics) and you cannot process the commands being sent to you, then you are -supposed- to use DTR to tell the host that you are no longer able to accept further commands. Admittedly, this is for direct connect situations, but 80% of all dcom still is direct connect. CTS hanshake is valid fron the other direction, the host may limit input from a remote device. Now, many systems/terminals use software handshakes, but these have their drawbacks; and as a result of these limitations offen force the receiving device to have a much larger buffer than is absolutely necessary (especially painful in terminals). of course any type of Null modem or null terminal interconnect causes a whole new set of problems.... Sorry to rant and rave, but I just went through all this, -Jim
zben@umcp-cs.UUCP (11/05/83)
[..] Spoken by fortune@wall: DTR is most certainly a handshake signal, and just as valid a one as CTS. 1. Read the standard 2. Find out how modems really work 3. Try to think about the global case, and not just the way YOU do things. In a direct connect situation anything that works is correct, but please don't push your own views upon others. Ben Cranston ...seismo!umcp-cs!zben zben@umd2.ARPA
phil@amd70.UUCP (11/06/83)
I would like to add to Ben's comments that if you try to use DTR
to handshake with your modem it will probably hang up on you.
Needless to say, I don't advocate using DTR for handshaking.
I also think Ben was being very gentle in his rebuke of fortune!wall.
--
Phil Ngai (408) 988-7777 {ucbvax|decwrl|ihnp4|allegra}!amd70!phil