Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!helios!bcm!dimacs.rutgers.edu!seismo!uunet!motcid!necka
From: necka@motcid.UUCP (William J. Necka)
Newsgroups: comp.dcom.modems
Subject: Re: Why does disconnect cause garbage before NO CARRIER?
Message-ID: <6508@khaki8.UUCP>
Date: 14 Feb 91 19:18:28 GMT
References: <653@twg.bc.ca> <3773.27b7e1b6@hayes.uucp>
Organization: Motorola Inc. - Cellular Infrastructure Div., Arlington Heights, IL 60004
Lines: 29

In article <3773.27b7e1b6@hayes.uucp> tnixon@hayes.uucp writes:

>Bill did mention that he has some proprietary (non-V.32) 9600 
>modems.  I should point out that _every_ proprietary 9600 modulation 
>scheme in common use (PEP, HST, MNP6, Hayes, Vadic, etc.) all 
>_require_ the use of error control; you can't use the modulation 
					^^^^^^^^^^^^^^^^^^^^^^^^^
>scheme without error control enabled, at least in async operation 
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>(Hayes does allow synchronous non-error-control ping-pong 
>operation).  Therefore, you should never see garbage on 
>disconnection from any of the proprietary schemes.

	One small correction. The USR HST does allow none error controlled
async operation. The draw back is that that the modem will not be able
to switch the high speed channel. This means that depending on if your
modem answered or originated, you will have the high speed or low speed
channel. If memory serves me correctly, setting AT&M0&N6 will accomplish 
this. The &N6 forces the modem to connect at 9600. Both modems need to
be configured the same. This feature has been in all the past USR HSTs, but
it was never popular.
______________________________________________________________________________
------------------------------------------------------------------------------
      --          x                              || William Necka -
   __/  \__/\/\/\/ \____     Motorola Cellular   ||    uunet!motcid!necka
  /  \__/  \      _/ [][\_ Arlignton Heights Il. || Opinions expressed are not
  \__/  \__/     (________)    708-632-4435      || necessarily my employer's.
_____\__/__________()__()________________________||____________________________
-------------------------------------------------------------------------------