from
The Free On-line Dictionary of Computing (8 July 2008)
Visual Display Unit
Display Screen Equipment
VDU
<hardware> (VDU, or "video terminal", "video display
terminal", VDT, "display terminal") A device incorporating a
{cathode ray tube} (CRT) display, a keyboard and a {serial
port}. A VDU usually also includes its own display
electronics which store the received data and convert it into
electrical waveforms to drive the CRT.
VDUs fall into two categories: {dumb terminals} and
{intelligent terminals} (sometimes called "programmable
terminals").
Early VDUs could only display characters in a single preset
{font}, and these were confined to being layed out in a
rectangular grid, reproducing the functionality of the
paper-based {teletypes} they were designed to replace.
Later models added graphics facilities but were still driven
via serial communications, typically with several VDUs
attached to a single multi-user computer. This contrasts with
the much faster single {bitmap displays} integrated into most
modern single-user {personal computers} and {workstations}.
The term "Display Screen Equipment" (DSE) is used almost
exclusively in connection with the health and safety issues
concerning VDUs.
Working with VDUs - UK Heath and Safety Executive
(http://hse.gov.uk/pubns/indg36.pdf).
(2002-11-09)