Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!ucsd!ucbvax!van-bc!cynic!curt
From: curt@cynic.wimsey.bc.ca (Curt Sampson)
Newsgroups: comp.sys.next
Subject: Re: /dev/drum???
Message-ID: <cLuas2w163w@cynic.wimsey.bc.ca>
Date: 8 Nov 90 04:06:23 GMT
References: <10193@uhccux.uhcc.Hawaii.Edu>
Organization: Mad Artists' Technological Hangout, Vancouver, B.C., Canada
Lines: 38

whelan@huey.uhcc.Hawaii.Edu (The Obscure Guru) writes:

> 	I was recently perusing the /dev directory on a next
> when I came upon the entry /dev/drum.  This seemed a bit odd, I thought
> that drum memory went out of fashion long, long ago.  The man pages
> didn't have anything to say about drum.  Does any have any insight
> on this odd device entry?

This actually has nothing to do with drum memory.  It's a part of the
UUCP system.

Long, long ago, even before version 6, somebody wanted to implement a
program to copy files between two machines running Unix.  At the time
there were no modems becuase there weren't even any telephones.  A
Bell Labs researcher who had just visited Africa seized upon the idea
of communicating by beating on drums, as the native Africans did.  He
added a drum interface to his PDP-11 and the device driver was called,
of course, /dev/drum.  Uucp would call a lower level program called
`bang' to activate this device driver.  Messages could also be sent
manually by typing `bang drum' at your shell prompt.  People soon
devised shell scripts that would take a mail message, convert it
appropriately, and call bang to send it.  Soon they were sending
multi-hop messages though several sites this way, which is how the
`bang path' got its name.

With the advancements in communications technology (semaphores in
particular), /dev/drum was removed from UNIX around version 6 or 7, I
believe.  The NeXT developers reinstated it on the NeXT because they
felt that a true multimedia machine should have as many options as
possible.

I hope this explanation helped.

cjs

curt@cynic.UUCP                  | "The unconscious self is the real genius.
curt@cynic.wimsey.bc.ca          |  Your breathing goes wrong the minute your
{uunet|ubc-cs}!van-bc!cynic!curt |  conscious self meddles with it."  --GBS