This section may eventually become so large that it will become a separate document (or a separate file for each terminal brand). This would be of use for the many cases where one lacks manuals for their terminals. You could help by writing up some info for the terminal you use and e-mailing it to me. Sometimes, useful information for a certain model may be found in the comments of the terminfo (or termcap) entry in the file /etc/termcap or terminfo.src.
CIT terminals were made in Japan in the 1980's for CIE Terminals. They ceased to be imported in the late 1980's. The company, CIE, still makes CItoh printers (in 1997) but has no parts for its abandoned terminals. Ernie at (714) 453-9555 in Irvine CA sells (in 1997) some parts for models 224, 326, etc. but has nothing for the 80 and 101. (The document you are now reading was written mostly on the 101e.)
To save the Set-Up parameters press ^S when in Set-Up mode. cit80: Contrast: knob on rear of terminal, cit101e: Brightness: use up/down arrow keys in Set-Up mode.
Don't confuse IBM terminals with IBM PC monitors. Many IBM terminals don't use ASCII but instead use an 8-bit EBCDIC code. It's claimed that in EBCDIC the bit order of transmission is reversed from normal with the high-order bit going first. The IBM mainframe communication standards are a type of synchronous communication in block mode (sends large packets of characters). Two standards are "BISYNC" and "SNA" (which includes networking standards). Many of their terminals connect with coax cable (RG62A/U) and naive persons may think the "BNC" connecter on the terminal is for ethernet (but it's not).
While this IBM system is actually more efficient than what is normally used in Linux, terminals meeting this IBM standard will not currently work with Linux. However, some IBM terminals are asynchronous ASCII terminals and should work with Linux on PC's. The numbers 31xx may work with the exception that 317x and 319x are not ASCII terminals. Before getting an IBM terminal, make sure there is a termcap (terminfo) for it. If their isn't, it likely will not work with Linux. Even if there is a terminfo, it may not work. For example, there is a termcap for 327x but the 3270 is an EBCDIC synchronous terminal.
The 3270 series includes the 3278 (late 1970's), 3279 with color and graphics, and the 3274 terminal controller (something like the 3174). They may be used for both BISYNC and SNA. The 3290 has a split screen (splits into quarters).
The synchronous IBM terminals don't connect directly to the IBM mainframe, but connect to a "terminal controller" (sometimes called "cluster controller" or "communication controller"). Some of these controllers can convert a synchronous signal to asynchronous so that in this case a synchronous terminal could indirectly connect to a unix-like host computer via its serial port. But there is still a major problem and that is block transmission. See section Block Mode.
These are antiques and represent the oldest terminals. They are like remotely controlled typewriters but are large and noisy. Made by the Teletype Corp., the first models were made in the 1920's and predate the computer by over 30 years. Early models used electro-mechanical relays and rotating distributors instead of electronics. Their Baudot code was only 5-bits per character as compared to 7-bit ASCII. See the book "Small Computer Systems Handbook" by Sol Libes, Hayden Books, 1978: pp. 138-141 ("Teletypes").
Digital Equipment Corporation made the famous VT series of terminals including the commonly emulated VT100. In 1995 they sold their terminal business to SunRiver which is now named Boundless Technologies. More information is available at Shuford's Website. Information on current products is available from the Boundless website. See Terminal Info on the Internet.
VT220: Some have a BNC connector for video output (not for input).