Path: utzoo!mnetor!uunet!oddjob!hao!ames!amdahl!oliveb!jerry
From: jerry@oliveb.olivetti.com (Jerry Aguirre)
Newsgroups: comp.dcom.modems
Subject: Re: Trailblazer, flow control, DMF32
Message-ID: <14856@oliveb.olivetti.com>
Date: 10 Feb 88 19:54:27 GMT
References: <272@coherent.uucp> <3249@cbmvax.UUCP> <10433@mimsy.UUCP>
Reply-To: jerry@oliveb.UUCP (Jerry Aguirre)
Distribution: comp
Organization: Olivetti ATC; Cupertino, Ca
Lines: 30
Keywords: telebit trailblazer emulex 19200
Summary: Emulex DH/DM can't handle 19200 telebit

In article <10433@mimsy.UUCP> chris@mimsy.UUCP (Chris Torek) writes:
>In article <3249@cbmvax.UUCP> grr@cbmvax.UUCP (George Robbins) writes:
>>BTW, anybody have any ideas on what's a good cheap interface to support
>>the Trailblazer on a Vax?
>
>The Able DH/DM, while old, works fine.
>
>>The DMF32 has a little baby FIFO ....  I wonder if there's any legit
>>way to enable the "hardware" X-on/X-off support on the DMF32?
>
>Beware; some clones (Emulex CS21/F, I think), and perhaps even DEC DMFs
>(I noted anomalous behaviour when I tried it), had bugs in the hardware
>flow control.  Nobody noticed until VMS V4.0, when DEC first started to
>use the feature.

I have had lots of problems trying to run 19200 to the Telebit with an
Emulex DH/DM interface.  The Emulex drops characters even on such short
sequences as "OK".  Needless to say this makes it hard to dial
successfully, much less recognize the login prompt from the other
system.  I even tried setting S60=3 in the hope that two stop bits would
slow the character arrival enough but there wasn't any noticable
improvement.

However the Telebit modem doesn't seem to handle 19200 very well either.
First is the already mentioned problem of getting it to auto-baud
reliably at 19200.  Then it will refuse to dial if I send it the ATDT
sequence at full speed.  It just sits there.  Even when I "tip" to the
modem and type the ATDT sequence slowly it will suddenly type "RNG" or
CNNT in the middle of my typing.  Very strange.
				Jerry Aguirre