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From: nather@utastro.UUCP (Ed Nather)
Newsgroups: net.dcom,net.micro.pc
Subject: Re: ibm pc and interrupt driven asynch output
Message-ID: <21@utastro.UUCP>
Date: Sun, 31-Mar-85 14:03:45 EST
Article-I.D.: utastro.21
Posted: Sun Mar 31 14:03:45 1985
Date-Received: Wed, 3-Apr-85 00:43:45 EST
References: <23097@arizona.UUCP> <324@bu-cs.UUCP>
Organization: U. Texas, Astronomy, Austin, TX
Lines: 38
Xref: watmath net.dcom:925 net.micro.pc:3630

> >Re: Problem with remote system (4.2bsd,PDP10) dropping chars at
> >1200 baud input
> 
> Yes, nuisance nuisance. Solutions:
> 
> 1. If you are not doing 'raw' [ie. need to send entire 256 char set]
> then you can put UNIX into TANDEM (stty tandem). This will cause
> UNIX to respond with ^S when buffer is about to overflow and ^Q
> when drained back down to a safe level. As long as you can quickly
> stop transmission (there's a few chars of grace) you'll probably
> be OK.
> 
We tried this and it doesn't work.  Uploading to a busy Vax loses characters.

> 2. Another approach is to put about a 1/10th of a second delay after
> every CR or 100 or so chars whichever comes first. This will work
> in general but unfortunately the needed delay will vary with remote
> system load. You may have to play around. I have used exactly
> 1/10th of a sec with TIP and it works most of the time on 4.2bsd
> and sometimes has to be raised to 2 or 3 tenths for SYSV.
> 
We tried this and it didn't work either.  System load changes too rapidly
and unpredictably.

> 3. The only other resort is a 'smart' protocol at the other end
> catching the characters and doing flow control and ACK'ing etc.
> but I bet this exactly what you don't want (otherwise, try KERMIT.)
> 
> 	-Barry Shein, Boston University
We tried this and it works fine.  The Kermit terminal emulator is superb,
the system is 100% reliable either directly connected or via modem, and we
can upload and download executable files without any problems.  Why kick a
dead whale along the beach when the solution is FREE?

-- 
Ed Nather
Astronony Dept, U of Texas @ Austin
{allegra,ihnp4}!{noao,ut-sally}!utastro!nather