Virtual Terminal (VT ) is the name of an OSI protocol and service. It is a common device interface that enables the display of data structures in different classes of devices. It allows a computer application to control a wide variety of terminals, keyboards and printers. Included is the control of cursor, colors, fonts, access rights, etc. It was defined that can be mapped a large number of classical character-based terminals. Idea was that a host does not have to know any controlling terminal type in a heterogeneous computer network, but only the control of a " virtual terminals ". The local implementation in the respective terminal type should indicate the elements of the OSI protocol to use, to use them to control its hardware. The simplest terminal protocol that could be simulated with this OSI protocol was Telnet protocol.
The virtual terminal protocol has not been able to put on the market, although there are several implementations, preferably for UNIX derivatives. In terminals, they were rarely implemented. Reason for this is that proprietary protocols for connecting terminals to hosts also secure the manufacturer of the hosts sales of the terminals.
See also: VT100
Norms and Standards
- ISO / IEC 9040:1997 Information technology - Open Systems Interconnection - Virtual Terminal Basic Class Service
- ISO / IEC 9041-1:1997 Information technology - Open Systems Interconnection - Virtual Terminal Basic Class Protocol - Part 1: Specification
- Network protocol