The DECserver was a highly successful family of asynchronous Terminal Servers made by DEC (Digital Equipment Corporation). The DECserver can be used with Linux with the help of the Linux-DECnet project and a few other things. On this page are some notes on setting up the DECserver 100 to run with Linux.

The DECserver 100 is a terminal server with a single 10Base5 (AUI) Ethernet port and 8 serial ports. The server has to download its boot image from a computer via the MOP protocol.


  • latd, A Digital Local Area Transport Daemon for Linux. This allows users to login to Linux from a LAT terminal server.
  • mopd, The Maintenance Operations Protocol loader daemon for Linux. This is needed by the DECserver 100 to download its software image.
  • An 10base5 (AUI) to 10baseT (UTP) transceiver (unless you use 10base5 or 10base2 for some reason)
  • A terminal or terminal emulator and the appropriate serial cables.
  • The boot image for the DECserver to download. The DECserver 100's image is called "PS0801ENG.SYS". You can download a copy of the image from or ask DavidGoodwin.


  1. Install both latd and mopd
  2. make the directory /tftpboot/mop
  3. copy PS0801ENG.SYS into /tftpboot/mop. The filename for the DECserver 100 must be PS0801ENG.SYS - this is what the DECserver 100 will request. Case does matter.
  4. Plugin a terminal to serial port 1 on the DECserver and a network cable to the adapter attached to the AUI port

When you turn on the DECserver you should see something like the following printed to the terminal on serial port 1:

Local -901- Initializing DECserver "08-00-2B-04-8B-A7" -- ROM BL8A, H/W Rev B.B
Local -902- Waiting for image load
Local -903- Loading from host "08-00-20-8E-16-0B"
Local -904- Image load complete

This means that everything should be working. You should be able to press enter now to get the DECserver login prompt. For this Hyperterminal (included with windows) does not seem to work. PuTTY and Tera Term Pro are good free options under windows.

For more advanced configuration and use, see the LAT page on the DECnet for Linux website:


If you see the following message:

Local -911- WARNING -- Non-fatal Hardware error detected
Server code 1000, terminal codes 00 00 00 00 00 00 00 00

after "Initializing DECserver..." then you have an Ethernet 1.0 transceiver - the DECserver 100 is designed to work with Ethernet 2.0 transceivers. See section of the DECserver 100 Terminal Server Operations Guide (AA-Z085A-TK, January 1985) for more information.

If you get the messages:

Local -902- Waiting for image load
Local -912- Load failure, timeout

then check that the filename of the image is "PS0801ENG.SYS" and is in the directory /tftpboot/mop - if it is not then this is probably your problem. Otherwise check that mopd and latd are running and your network link is functional. You could also try setting the DECserver 100 to the factory default settings.

Resetting to defaults

To set to factory default settings hold down the S1 button while unplugging and plugging in the power cable. This should reset all settings to factory defaults including the image name and privileged password (to SYSTEM).

See Also