DEC Server

From: Fred N. van Kempen <waltje_at_pdp11.nl>
Date: Tue Sep 2 19:59:59 2003

On Sat, 30 Aug 2003, Kleb J.F wrote:

> Hi Stuart
Err... this is a mailing list, not a personal address.

> I was recently given two DEC Server 100's. I was wondering if you could
> help me find some information on these devices and what they were, and could
> be used for.
DECserver 100's were the first of DEC (Digital)'s line of ethernet
terminal servers. These terminal servers connected to an Ethernet
on one end (like the VAXen, PDP-11's et al), and on the other end
connected to terminals and modems. These servers ran the LAT
(Local Area Transport) protocol, which is somewhat like what TELNET
does over IP/TCP these days... it connects a terminal to a login
session on a host system, such as a UNIX or VMS host. The LAT
protocol then takes care for efficient transport of keystrokes
and screen data over the network.

At the time, this was a revolutionary change from how terminals
were otherwise connected; up till then, host systems spent a lot
of their time (read: brain power, computing resources) on the
actual servicing the serial lines to which the (sometimes hundreds!)
of terminals were connected. By offloading this processing to the
dedicated 'dec servers' (hence the name: DECserver), host systems
could spend more time on actual work.

It also allowed terminals to be further away from the hosts, since
the rules for serial line lengths no longer applied, but the new
rules of Ethernet cabling ruled instead.

Documentation (and load software) for these devices is still
available.

Cheers,
        Fred
Received on Tue Sep 02 2003 - 19:59:59 BST