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Introduction to SeqLab

X-windows

SeqLab is a graphical user interface (GUI) based on the X-windows network protocol.

X-windows is a client-server system, similar in many respects to the HTTP system that is the basis for the World Wide Web.

X-windows allows you to run an application on a powerful machine (such as the RCR's Alpha) and have the results displayed on another computer (the X-terminal) over the network.

X-windows is a network protocol that has been implemented in a wide variety of different hardware and software environments (UNIX, VMS, Macintosh, MS Windows, etc).

In a reversal of the usual network computing terminology, the program that runs on your desktop computer (Mac, PC, or X-terminal) is called the server and the program that runs on the host computer is called the client.

The server displays graphics on the screen and passes keystrokes and mouse clicks to the client.

There are many different X-windows clients available for various types of desktop computers.

For the Macintosh and Windows95 PC's there is a free program called MI/X created by a company know as MicroImages (www.microimages.com). This is an adequate if somewhat clumsy X-server.

A much nicer X-server, called eXodus, is available (for both Macs and PCs) from the White Pine Software Company for $118.

The X-windows protocol is very computationally demanding.

It is not possible to use this application on very old, slow computers.

I was not able to get acceptable performance with MI/X on a Mac IIci although eXodus was useable on this machine.

Any Power Macintosh model should give acceptable performance.

Setting up an X-windows server on your desktop machine is not trivial.

The RCR is in the process of developing step-by-step guidelines for this process.

In addition to configuring the server to find the client program hosted by the RCR's Alpha, you must also configure your VMS session to send results from GCG back to the X-server where you are working.

Use the SET DISPLAY command as follows:

set display/create/node=128.122.100.100/trans=tcpip

where the node is the IP number of the machine where you are working.

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Using Computers for Molecular Biology
Stuart M. Brown, Ph.D, RCR, NYU Medical Center

Comments to: browns02@mcrcr.med.nyu.edu