It proved enormously successful during the Battle of Britain, and is credited as being a key part of the RAF's success.

updating an outdated computer system would be an example of-53

The radars determined the map coordinates of the enemy, but could generally not see the fighters at the same time.

This meant the fighters had to be able to determine where to fly to perform an interception but were often unaware of their own exact location and unable to calculate an interception while also flying their aircraft.

Operators used light guns to select targets onscreen for further information, select one of the available defences, and issue commands to attack.

These commands would then be automatically sent to the defence site via teleprinter.

Similar systems began development with the Royal Canadian Navy, DATAR, and the US Navy, the Naval Tactical Data System.

A similar system was also specified for the Nike SAM project, specifically referring to a US version of CDS, coordinating the defense over a battle area so that multiple batteries did not fire on a single target.Against propeller driven bombers flying at perhaps 225 miles per hour (362 km/h) this was not a serious concern, but it was clear the system would be of little use against jet-powered bombers flying at perhaps 600 miles per hour (970 km/h).The system was also extremely expensive in manpower terms, requiring hundreds of telephone operators, plotters, trackers and all of the radar operators on top of that.Information was fed to the DC's from a network of radar stations as well as readiness information from various defence sites.The computers, based on the raw radar data, developed "tracks" for the reported targets, and automatically calculated which defences were within range.Each DC also forwarded data to a Combat Center (CC) for "supervision of the several sectors within the division" SAGE became operational in the late 1950s and early 1960s at a combined cost of billions of dollars.