Telecommunication control unit

From Wikipedia, the free encyclopedia
Jump to: navigation, search

A telecommunication control unit (TCU) was device present in the now outdated mainframe computers of the past that were attached to a multiplexer channel. TCUs freed mainframes from handling the data coming in and out of RS-232 ports. The TCU would support multiple terminals, sometimes hundreds. Many of these TCUs could support RS-232 when it was required, although there were other serial interfaces as well.