Dumb Terminal Definition

A dumb terminal is a computer terminal that consists mostly of just a display monitor and a keyboard (and perhaps a mouse as well). It has no internal CPU (central processing unit), and thus has little or no processing power. Likewise, there is no hard disk drive (HDD).

A terminal is a device that allows communications with a computer. Dumb terminals are connected to a network that includes one or more servers, which are computers with sufficient processing power to run any application programs that are being accessed through the dumb terminals.

Dumb terminals were sometimes called glass teletypes because they were similar to teletype machines to which display monitors (whose front surfaces are made from glass) were added. Also referred to as a teletypewriter and given the acronym TTY, a teletype machine is a now generally obsolete electro-mechanical typewriter that was widely used to communicate typed messages from point to point through a simple electrical communications channel. Teletypewriters were also used as the first computer terminals.

The terms smart terminal, network computer and thin client are sometimes used to refer to enhanced dumb terminals that provide additional resources to perform local editing and simple processing. That is, they have some processing power, but they still rely on servers in the network for much or most of their processing and their access to application programs. They likewise boot from a server in the network. Booting refers to installing the operating system into the memory of the terminal.

Many businesses and other organizations favored networks of dumb terminals because they could provide a single operating system with a single version of software running on it for all users. As they have no moving parts (other than the keys on the keyboard) that can break down or lose data, dumb terminals can provide greater virus resistance and data security as compared with full-fledged personal computers, and they can be more reliable. They are also quiet, easy-to-deploy, and simple to manage remotely. However, some users did not like their restricted ability to control the processing of information on such systems.

In contrast to earlier dumb-terminals, today's thin clients provide much more user-friendly displays, including multiple windows, web browsing and other features of conventional personal computers.

Dumb terminals were produced by a number of major companies in the 1970s and early 1980s, including DEC, Heath, IBM, Lear-Siegler, Televideo and Wyse. However, the rapid drop in the cost and increase in the power of personal computers made it more economical for businesses to use them in place of dedicated dumb terminals. It is very easy to configure personal computers so that they can emulate dumb terminals, thin clients, or terminals with any desired level of intelligence.

Created September 2, 2005.
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