Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!husc6!cmcl2!nrl-cmf!ames!ucbcad!zen!ucbvax!NGP.UTEXAS.EDU!herzlich
From: herzlich@NGP.UTEXAS.EDU (Larry Herzlich)
Newsgroups: comp.os.vms
Subject: Terminals to LAVc nodes
Message-ID: <8711081916.AA23939@ngp.utexas.edu>
Date: Sun, 8-Nov-87 14:16:54 EST
Article-I.D.: ngp.8711081916.AA23939
Posted: Sun Nov  8 14:16:54 1987
Date-Received: Wed, 11-Nov-87 19:39:19 EST
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The ARPA Internet
Lines: 38

In Steve Ward's article about `local area vaxcluster performance',
he mentioned using direct lines to the MicroVAXes versus using
terminal servers.

>Terminal servers can be used instead of hardwired serial ports, but
>each multiuser node should have extra memory and derated by a few
>concurrent logins to compensate for the extra terminal server overhead.
>Steven Ward
>Smithsonian Astrophysical Observatory

I would like to configure a system with direct lines but I don't see
any reasonable way to do this using DEC hardware.  Putting 3 DHQ-11's
inside a MicroVAX seems like the limit due to panel inserts.  I'm not
even sure this is possible if we are using a KDA50 controller on the
MicroVAX at the same time. I think I'd run out of slots and panels in a
normal BA123 box.

Now, picture the scenario of the MicroVAX 3500/3600.  I can license
the system for 20 users or as many as 40 users on the big VAXserver
3600/TU81/RA82 configuration.  How the heck can I get 40 users into
that system?  I believe that the performance is there at 3 MIPS but I
don't see any way of getting 40 lines into the H9642 cabinet.  Maybe
one of the field test sites can discuss the layout of the I/O
distribution panel on the MicroVAX 3500 BA213 or the MicroVAX 3600
H9642 cabinet?

Remember, I DO NOT want to use terminal servers.  I don't like the
idea of spending 30K for a DECserver 500.  I also don't want to
discover that my Ethernet (even with a bridge to isolate the traffic)
is going to be saturated by my LAVc terminal traffic.

DEC, are you listening?  Does `DEC Have it now?'

----
Larry Herzlich				herzlich@ngp.cc.utexas.edu
University of Texas at Austin		CCCS001@UTADNX  -- BITnet
Computation Center 			UTSPAN::UTAIVC::CCCS001 (SPAN)
User Services Division			..!seismo!ut-sally!ut-ngp!herzlich