SACCS

The Strategic Automated Command and Control System (SACCS) is a United States Strategic Command command and control system to coordinate the operational functions of United States nuclear forces (ICBMs, nuclear bombers, and SLBMs).

The ITT 465L Strategic Air Command Control System (SACCS) with its IBM AN/FSQ-31 SAC Data Processing Systems attained operational capability on January 1, 1968; and its gradual replacement began on October 6, 1975, when the SACCS original IBM 4020 Military Computers were replaced by Honeywell 6080 computers (remaining FSQ-31 components were entirely decommissioned in November.) The Strategic Air Command Digital Information Network was deployed to replace SACCS' "Data Transmission Subsystem and part of the Data Display Subsystem", e.g., on November 5, 1986, "Martin Marietta Corporation technicians began installing SAC Digital Network (SACDIN) equipment in 91st Strategic Missile Wing missile launch control centers (i.e., either a HUTE rack or MBCP rack). On February 20, 1987, "SAC declared initial operational capability for the SAC Digital Network when [it] operated successfully between the Headquarters SAC Command Center and the 55th Strategic Reconnaissance Wing Command Post, both located at Offutt AFB, Nebraska, and the 351st Strategic Missile Wing Command Post at Whiteman AFB, Missouri." SACDIN eventually "linked 135 locations and permitted two-way message communications with ICBM launch control centers for the first time," and the Ground Wave Emergency Network communication system had a Final Environmental Impact Statement issued in September 1987.

...
Wikipedia