Computer developed by a panel of Pentagon engineers as a substitute for the Dial-home device on Earth. The development of the computer took some 15 years, as it was difficult to match the Stargate's electronic "pulse" language with corresponding gate functions.
The computer is at the heart of a series of integrated Stargate control systems inside Stargate Command, which also includes iris controls and radio communication systems allowing for transmission and reception through an active wormhole.
Similar dialing computer systems have been installed on off-world Earth outposts where a D.H.D. is not in use, including the Midway Space Station.
"Stargate" the Movie - Dr. Jackson uncovers the seventh symbol, the point of origin, and opens the Stargate for the first time in some 50 years.
The Fifth Race - Colonel O'Neill, under the control of the downloaded Ancients knowledge, rewrites the dialing computer to include a plethora of new gate coordinates not included in the Abydos cartouche, and therefor unknown to the Goa'uld.
Serpent's Song - With Sokar knocking on the S.G.C.'s door, Carter is forced to devise a method of increasing the dialing computer's speed to establish an out-going wormhole.
New Ground - Carter reveals that she has written a program that automatically attempts to reconnect to Stargate addresses that could not previously be reached.
Red Sky - Samantha Carter has to disengage the safety protocols on the computer to get the dial out to succeed.
 - After seizing control of Midway the Wraith successfully hack its computer systems, dialing the Gate Bridge to Earth.