X Windows Display

X windows display

Setting up an X windows Display on VMS

If you are using SSH, please review the information in connecting to ISIS about SSH and X windows displays; you will probably not need to set your display manually as described here. 

Configuring and using a PC X Windows emulator

Most graphical programs on VMS use the X windows protocol for displaying terminals and graphics, and various PC programs exist to provide an "X –server" for the PC. For this example we will use Hummingbird Exceed v7.0, which is usually installed at ISIS. In X windows speak, a terminal on a remote machine is referred to as a "client".

Creating Remote Sessions

For this you should use the "Client Wizard" which is located in the "Start – Programs – Hummingbird Connectivity 7.0 – Exceed" menu.

  • On the first page in the "Host:" box type the name of the ISIS machine (e.g. "isisa.nd.rl.ac.uk") and for the "Host type:" select "DEC VMS" from the list.
  • On the second page, leave the "application" as terminal and the boxes as their default values
  • On the third page you can enter a username and/or password to be used for the session, if you leave either blank you will just be prompted for them later, which may be preferable.
  • On the fourth page you can select the name of the menu shortcut and where it will be located – you may want to select "Hummingbird Connectivity 7.0" or "accessories", or type in a new name such as "Exceed Clients"; this would then let you activate applications via "Start – Programs – Exceed Clients"

When you start the application, there is a "remember password" box. I usually select "no" as the program has been know to then use the stored password later for the wrong host.

Once logged in, type SHOW DISPLAY to check your X-windows connection. You should see something similar to the following:

THOTH> show display
Device: WSA52: [super]
Transport: TCPIP
Server: 0
Screen: 0

If you instead get output of the form

THOTH>show display
%DECW-W-OPENIN, error opening DECW$DISPLAY as input
-SYSTEM-W-NOSUCHDEV, no such device available

Your display has not been set up correctly during the login and you will need to set it manually with the SET DISPLAY command – see below


If your connection looks OK, as a test type either MC DECW$CLOCK or CREATE/TERM/DETACH

Alternative Remote Sessions

The "client wizard" approach uses the "rexec" function to start a remote terminal and it should set the display automatically over the network. This may not always work for a variety of reasons, often caused by a firewall, and so an alternative "manual" approach will now be discussed.

1 – Start up you X terminal emulator program on your PC so that it is running in the background, but do not use it to make a connection. Basically, it will just sit and wait for incoming X requests

2 – Use Telnet to connect to the ISIS machine and logon as normal

3 – Set the X windows display with SET DISPLAY/CREATE /NODE=my.machine.name /TRAN=TCPIP

4 – To test the connection, start a new terminal with CREATE/TERM/DETACH or type MC DECW$CLOCK

"my.machine.name" will typically be the IP address of your PC – you can obtain this by typing IPCONFIG in an MS-DOS/Command Window. If you are behind a firewall, "my.machine.name" may instead be the address of your firewall X proxy – you will need to consult you computing service about what to use in this case. Typically you would be assigned a "dummy" DISPLAY name to use, which will contain the address of the firewall, and then you would be given either a port number to use (X windows ports start at 6000 and go up) or a UNIX style DISPLAY name of e.g. "my.machine.name:0.0" If you were told to use "my.firewall.name:1.0" instead, then the equivalent VMS command would be

SET DISPLAY /CREATE /NODE=my.firewall.name /SERVER=1

If you were told to use "my.firewall.name:1.3" it would be


Port Number

UNIX Command

VMS command


Setenv DISPLAY "my.firewall.name:0.0"

SET DISPLAY /CREATE /NODE=my.firewall.name


Setenv DISPLAY "my.firewall.name:1.0"

SET DISPLAY /CREATE /NODE=my.firewall.name /SERVER=1


Setenv DISPLAY "my.firewall.name:2.0"

SET DISPLAY /CREATE /NODE=my.firewall.name /SERVER=2

Optimal Exceed Settings

Either right click on the Exceed icon on the Windows task bar and select "Tools – Configuration", or go into Xconfig which is located in the same menu location as "Client Wizard" above.

  • Double click on "Keyboard input" and select "decemuk.kbf" as the alternate keyboard mapping – OK this
  • Double click on "X selection" and select "clipboard" from the "X selection associated with edit operations" box – OK this

Exceed allows you to switch your keyboard mappings "on the fly" by right clicking on the exceed icon on the task bar and selecting "Tools – switch to alternate keyboard". The DECEMUUK keyboard emulates a VMS keyboard and is useful for the VMS EDT editor (see later) - with this in operation, F12 becomes the VMS "DO" key and "Num Lock" becomes "GOLD" etc

Common Problems

The most common X windows problems are usually:

  1. The DISPLAY name/address of the PC has been entered incorrectly on VMS
  2. Security/access control settings on your local PC are stopping the connection
  3. A firewall at your local establishment is stopping X windows connections from ISIS  - you should use SSH to forward you X connection 
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