MK 68 Gun Fire Control System (GFCS) From the Federation of American Scientists Military Analysis Site:
"The MK 68 provides frigate, destroyer and cruiser-sized surface combatants with a dual purpose fire control system effective against air and surface targets including targets ashore. The Mark 68 control system consists of a manned topside director; a conical scan acquisition and tracking radar; an analog computer that solves the target motion and gun ballistics equations; and a stabilization unit. In production for over 25 years, several variants exist including a Digital Upgrade modification installed in limited quantities after 1975 and continuing into 1985. Over 80 systems continued in active service into the 1990s and many beyond that time. The hardware and software architecture of the computing system within the Digital Upgrade variant has evolved further into the gun to be installed in the Arleigh Burke class of destroyers."
