![]() search |
TALISMAN
general
Information
Unix server |
|
drum-explanation.shtml
|
Erlkönig: drum-explanation.shtmlFrom: curt@cynic.wimsey.bc.ca (Curt Sampson) Subject: What is /dev/drum? Date: 31 Jan 91 00:30:08 GMT 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. |