General Information

Applicable to most character-cell/remote-graphics terminals

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A Web essay by Tom Van Vleck gives us some perspective on how serial computer terminals have been used and improved since the 1960s. For glimpses of how computer hobbyists of the early 1980's used character-cell video terminals with the home computers of the day, you can visit a library and look up these articles ftom BYTE magazine.

Information on setting up a Unix or Linux system for use with terminals or terminals emulations is here, whereas, information on terminal emulations themselves is here.

When you are trying to use any dumb terminal (or even a smart terminal) with a remote host, it is helpful to remember that there are two sets of parameters in play:

The two sets of parameters interact:  the host computer can sometimes discover how the local terminal is set, and the computer will likely adjust what control characters it sends according to its guess of how the video terminal may behave.

If you need beginner's help on how to login to a Unix system using a terminal, you can start by reading this introductory video-terminal tutorial for Unix by Anthony Lawrence. You can also read introductory Unix materials from here at the University of Tennessee, or you can read an equivalent introduction to Linux. A few common terminal-related questions are answered in the Boston University Unix User's Guide.

You can read this Introduction to Telnet, describing the Internet's original remote-terminal protocol. And it may be helpful to look at the "telnet" section of the TCP/IP Frequently-Asked Questions document. (And there is the "Mini-FAQ" on TCP/IP applications. On the other hand, if you just want some fun, you can sing The Telnet Song or just look at the currently lighted face of Earth in ASCII. Dmoz.org lists some Unix-shell-access providers, and the the Noise-Level Zero conferencing system a web-page telnet interface.)

To view the text parts of web pages using a character-cell terminal, you can use the Lynx web browser.

But, if you have some idea of using a character-cell terminal to connect to a remote computer running Microsoft's Windows NT, you'd better read this first, and then have a look at this.

(return to Video Terminal index page)

User Issues


Programmer/Administrative Issues


Supporting different kinds of terminals...

Unix and Linux systems typically supply a function library and a database that permit applications programs to work with many different kinds of character-cell terminals. The library is "curses" (or "ncurses") and the database is either "terminfo" or "termcap".

Here you can read some archived discussion of the termcap and terminfo databases, and the curses library, and how the entries control the attributes of displayed data.

Also, Tony Lawrence has placed on his website some general principles of programming for terminals using terminfo and termcap.

Helpful Book: O'Reilly & Associates published a book called termcap & terminfo by John Strang, Linda Mui, and Tim O'Reilly. From the same publisher, another helpful book is Programming with curses by John Strang, which describes the UNIX library of functions for controlling a terminal's display screen from a C program.

The original reference on curses is the BSD project documentation volume Screen Updating and Cursor Movement Optimization (here in PDF). Now, however, curses functions are part of the X/Open Unix Standard, as documented here.

Another book is UNIX Curses Explained by Berny Goodheart (Prentice Hall, ISBN 0-13-931957-3), which discusses programming both using the curses package and using low-level control codes obtained directly from terminfo. And there is Pradeep Padala's NCURSES Programming HowTo.

A book on a related topic is The Working Programmer's Guide to Serial Protocols by Tim Kientzle. This volume discusses Kermit, Zmodem, and other protocols, and provides sample code in C++. Although now out of print, you may possibly be able to locate a copy. Select this and that to find out more. Some source code described in the book is available here at the Dr. Dobbs site.

If you need a different termcap or terminfo entry for some particular terminal, you can get it from Eric Raymond's comprehensive master terminfo file.

Another way to cope is to repair the terminal-database entry yourself. Walter Zinz of Unix World wrote chronicles of how he repaired the termcap and terminfo entries for his AT&T 7300 screen.

Another possible reference book, this one readable directly from the Internet, is 

     UNIX Hints and Hacks
     by Kirk Waingrow.
     Copyright 1999 MacMillan/Que.
     ISBN 0-7897-1927-4.

Here is the chapter describing character-cell terminal displays and emulations. (courtesy of umd.edu)

Some may wish to read about AIX's low-function terminal subsystem.

Software elsewhere on the Internet


Terminal-Related Information Elsewhere on the Internet

Usenet (inet) newsgroup: comp.terminals

Christian Blum wrote an excellent essay The_Serial_Port. For TP access to that and several other of his useful files, select this. (Here is the Web location at "repairfaq.org".)

(As of April 2005, with excessive traffic to the "repairfaq.org" domain, Sam Goldwasser has provided mirror sites.)

You can read an interview with the president of Wyse Technology to learn his view of the future of thin clients. Another approach to the "thin client" is Sun's SunRay desktop appliance.

Several thin-client technologies are on display at the Thin Planet.

Standards and other Reference information elsewhere on the Internet

Organizations

Internet RFCs (Request for Comment Documents)

Vendor Information

Video Terminal index page

Information on DEC terminals.
Information on IBM terminals.
Information on Televideo terminals.
Information about "various" terminals: many types, including Wyse/Link, ADDS, ADM, HP, AT&T, Volker-Craig, Tektronix, etc.

Information on terminal emulation (on a PC or otherwise).
Information on terminal emulation in X Windows in Unix and Linux, especially xterm.

Information on keyboards, mice, and other user-input devices.
Advice on setting up an operating system to use terminals.
Tangental information on technologies for display of data.
Links to various computing technology.