device control

from The Free On-line Dictionary of Computing (8 July 2008)

Device Control

   <character> One of the four {ASCII} characters, {DC1}, {DC2},
   {DC3}, and {DC4}, once used to remotely control equipment
   (e.g. a {paper tape} reader) via electromagnetic switches.
   The characters were usually paired, DC1/DC3 turning one device
   on/off, and DC2/DC4 another.

   [Other examples of equipment?]

   (1996-08-20)