UNIX borns as a terminal based Operating System. Using the term "terminal based" we understand that a company generally works with a single UNIX system: SCO UNIX, SCO Xenix, UNIX Interactive or others, with a Serial Multi-Port card like Specialix, Digiboard, Cyclades or other where are connected dumb terminal: Wyse, Tektronix or others, and each user have its own terminal, a non-graphical terminal.

After the X Window release and its adoption by UNIX vendors (IBM, Sun, HP, Digital and others) as the graphical "standard" interface, appears the X Terminal concept.

An X-Terminal is a Graphical terminal composed by a keyboard and a display including a network connection. Also serial ports where local serial printers are available in almost all these harware.

We present here, probably the most worldwide popular X-Terminal, released by NCD.
 
 

In other words, and from people that never see one, the X-Terminal is similar to a PC, but without a hard-disk. In true, is not a PC ... but is graphical terminal ... an X-Terminal.

Actually (after a MS Windows product based released), NCD back to front.
 

How to setup an X-Terminal on a local network

How these terminals without a hard-disk may run X ?. If you think on on the XDM, that is the graphical X Window login, and evaluate also that is possible from any xdm to enter in any other X based system, would be clear about the possibility.

About the technical steps to apply is important to said that while in the 90's basically the was used bootp, as the network daemon to launch the connection, load the XFonts and run X, in nowadays is used the dhcpd, that automatically, assign a

I remember when an Interactive UNIX on a 386, in 1991, crash after the connection of the third X-Terminal.

The answer is particularly easy. The bootd does the job. However, while in dhcpd.
 
 

# example /etc/bootpdtab file
# the global section

global:\
   :sm= 255.255.255.0:\
   :ds=10.0.0.1:\
   :gw=10.0.0.1:\
   :ht=ethernet:\
   :hd=/tftpboot:\

# hosts
machine1:tc=global:ha=00:00:C0:12:B1:01:ip=157.151.7.200:bf=machine1:
machine2:tc=global:ha=00:00:C0:C1:B1:11:ip=157.151.7.201:bf=machine2:
 

The Linux Terminal Server Project (LTSP)

Because basically, Linux is the "normal" substitute for UNIX in any sense and also because the source for networking and X Window are available, from some years there are available a project called: LTSP, that stand for the Linux Terminal Project.

Basically, this project is a 'high' evolution of the normal steps to setup an X-Terminal in UNIX days.

LTP includes all the necessary to get your XDM login on your diskless system. You need to move to the server. The word server here haves the following sense: The computer that runs the X Window Server where the remote X-Terminal will connect.

The LTSP distro includes the different software:

• rpm -ivh ltsp_core-3.0.0-1.i386.rpm
• rpm -ivh ltsp_kernel-3.0.1-1.i386.rpm
• rpm -ivh ltsp_x_core-3.0.1-1.i386.rpm
• rpm -ivh ltsp_x_fonts-3.0.0-0.i386.rpm

Just install it and check.

The entire procedure is covered in: http://www.ltsp.org/documentation/ltsp-3.0.0/ltsp-3.0.html

We prefer that the reader complete this as an exercise.

After some minors check ... about ten minutes. (Relax you can take also twenty minutes) ... you will get the LTSP xdm login:
 

We cover as an exercise the installation of the LTSP package on your Server, for the "eventual" X-Terminal installation.
 

A PC or an X-terminal ?

Probably a newbie may be interested in install an X-Terminal on its network. Before he/she start this "adventure", I want to explain that we covers the X-Terminal concept for a pro-Certification reasons. However, the concept of X-Terminal haves sense inside a company or for personal test,

In the years, when X-Terminal become popular worldwide, was basically to add different workstations supporting only a hardware cost, the X-Terminal cost. In those days, the cost of a UNIX system changes dramatically depending of the users that access the system.

Today, we have Linux. Also, in around 1992, the BSD was available for free and offers UNIX power without to count the number of users that access the system. Linux continues this effort under a new flavor: the Linux kernel flavor.

The same criteria "pay-per-user' generate the UNIX business and terminal based use. For some companies also the X-Terminal for a use and graphical advantage was expensive in those days.

Actually, we have the PC. The word 'compatible' , basically generate almost all IT business in the world. New, PC may be 'really' unexpensive.

However, if you have a 'very-old' PC like an IBM XT or similar ... you may convert to an X-Terrminal to use in your Network.

If you have instead a i386 with a Hard-Disk, 200 MB or so ... install Linux! without to force your server and take full advantage of Linux without to force.

The VNC Project

The VNC (Virtual Network Computing) is a set of programs that allows to run different graphical enviroments in any place ... virtually.

VNC was invented by the Olivetti Research Laboratory (ORL) in UK. In January 1999, AT&T acquired ORL, founded 12 years earlier. Recently jointly funded by Oracle, to create AT&T Laboratories in Cambridge.

VNC runs everywhere.
 
 

... You can run MS Windows inside X Window	... We can run X Window on the Mac ...	We can execute X Window program from a simple Internet Explorer page!

Generally modern Linux installation includes VNC.
 

[root@ftosx1 root]# rpm -qi vnc
Name        : vnc                          Relocations: (not relocateable)
Version     : 3.3.3r2                           Vendor: Red Hat, Inc.
Release     : 18                            Build Date: Tue 24 Jul 2001 12:34:31 PM CEST
Install date: Wed 09 Jan 2002 02:18:27 PM CET      Build Host: stripples.devel.redhat.com
Group       : User Interface/Desktops       Source RPM: vnc-3.3.3r2-18.src.rpm
Size        : 192453                           License: GPL
URL         : http://www.uk.research.att.com/vnc/
Summary     : A remote display system.
Description :
Virtual Network Computing (VNC) is a remote display system which
allows you to view a computing 'desktop' environment not only on the
machine where it is running, but from anywhere on the Internet and
from a wide variety of machine architectures. This package contains a
client which will allow you to connect to other desktops running a VNC
server.
[root@ftosx1 root]#

We will not comment more about VNC here. However the concept is basically the X Window concept extended from the networking point of view.
 

Exercises

1. Install an old PC as a X-Terminal, using the http://www.ltsp.org/documentation/ltsp-3.0.0/ltsp-3.0.html instructions.
2. More interesting: Configure VNC to solve your System Integration problems.

1. What is a X-Terminal ?
2. Where interact an X-Terminal user, when run its programs ? ... or Where is the Hard-Disk ?
3. What is XMD ? What means "xdm" ?
4. Is possible using "xdm" log into an X W7indow System about 2 miles far ?
5. What type of Network Protocols supports X Window System ?
6. Generally is included a hard disk in an X Terminal ?
7. How are loaded the fonts for the X Window System ?
8. How is loaded the X Window System ?
9. List three companies that produce X Terminals in the 90.
10. What is LTP ?
11. What is VNC ?

Read the answers to the exercises.

Check the Interactive Exam Cram WebMaster: 

Internet Resources for this Chapter.

• http://www.ncd.com/
• http://www.ltsp.org/index.php
• http://www.ltsp.org/documentation/ltsp-3.0.0/ltsp-3.0.html
• Sources are at: http://sourceforge.net/project/showfiles.php?group_id=17723
• http://www.uk.research.att.com/vnc/