Xref: utzoo comp.sys.att:8149 unix-pc.general:4210
Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uwm.edu!psuvax1!rutgers!att!dptg!mtunb!jcm
From: jcm@mtunb.ATT.COM (John McMillan)
Newsgroups: comp.sys.att,unix-pc.general
Subject: Re: 7300 and 9600 baud modems (VT220 suggestion, and question)
Message-ID: <1709@mtunb.ATT.COM>
Date: 29 Nov 89 14:19:23 GMT
References: <3311@convex.UUCP> <24425@cup.portal.com> <581@limbic.UUCP> <4197@eagle.wesleyan.edu>
Reply-To: jcm@mtunb.UUCP (John McMillan)
Organization: AT&T ISL Middletown NJ USA
Lines: 23

In article <4197@eagle.wesleyan.edu> flinton@eagle.wesleyan.edu writes:
>In article <581@limbic.UUCP>, gil@limbic.UUCP (Gil Kloepfer Jr.) writes:
>> 
>> A problem I *have* noticed is calling at Trailblazer speed to a system
>> from my VT100 *through* the UNIX-pc results in many lost characters
>> on my receiving end.  I'm not sure whether this is due to the 3B1 not
>> being able to handle 2 serial ports at high-speed, or the VT100 being
>> too slow and causing too many characters to be queued-up at the device
>> driver level.  In any event, forcing the Telebit speed to 9600 baud
>> doesn't fix the problem.

	Answer:  The 3B1 suffers overrun of the RS232 chip input
		buffers (3) while driving an RS232 output device.

		I do not LIKE the above fact, but I've found no
		solution to it.  There are just too few CPU cycles
		to handle all the interrupt-driven processing.
		Attempts to solve this have failed.

		If you were displaying the data on the console,
		the problem would not occur.

john mcmillan	-- att!mtunb!jcm -- saying "Good Byte for Now..."


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