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inane: Re:/dev/drum???
It's not often the really obscure aspects of Unix are explained so well.
I'm not sure what newsgroup keith found this in ...
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Finder: keith%dali@gatech.edu
Subject: inane: Re:/dev/drum???
Date: 8 Nov 90 04:06:23 GMT
From: amdcad!uunet!cynic.wimsey.bc.ca!curt (Curt Sampson)
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
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