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Path: utzoo!utcs!lsuc!pesnta!hplabs!oliveb!jerry
From: jerry@oliveb.UUCP (Jerry Aguirre)
Newsgroups: net.periphs,net.unix-wizards,net.wanted.sources
Subject: Wanted: KMC11 driver for 4.1BSD VAX
Message-ID: <321@oliveb.UUCP>
Date: Mon, 18-Mar-85 14:58:07 EST
Article-I.D.: oliveb.321
Posted: Mon Mar 18 14:58:07 1985
Date-Received: Tue, 19-Mar-85 20:22:29 EST
Distribution: net
Organization: Olivetti ATC; Cupertino, Ca
Lines: 21
Keywords: wanted, KMC11, driver, Vax, DZ11, performance, interrupts
Xref: utcs net.periphs:641 net.unix-wizards:11801 net.wanted.sources:629

The October Bell Technical Journal* has an article that describes the
performance improvements that have been made to Unix over the years.
One item is the use of the KMC11 front end processor to reduce the
interrupt overhead on Vax computers equipped with DZ11 type tty ports.
The article says the thru-put can be boosted to better than what can be
achieved with DH interfaces.

Our European office has many Vaxes that are, because of maintenance
requirements, equipped with DZs.  These systems are rather slow, in part
because of the DZ interrupt overhead.

Does anybody have or know of an available KMC11 driver?  The systems
are VAX-750 and Vax-780 running 4.1BSD.  Modifying a driver from another
Unix version is a possibility though a 4.1 version would be best.

				Jerry Aguirre @ Olivetti ATC
{hplabs|fortune|idi|ihnp4|tolerant|allegra|tymix}!oliveb!jerry

* AT&T Bell Laboratories Technical Journal, October 1984 Vol.63 No.8
  Part 2;  "The Evolution of UNIX System Peformance" by J. Feder;
  Page 1807.