Inside the direction centers, were two AN/FSQ-7 computers, each one measuring 7,500 square feet and consisting of 60,000 vacuum tubes, 175,000 diodes, 13,000 newfangled transistors, and 256KB of magnetic core RAM. New power lines had to be constructed at each site to support the electrical consumption of 3MW of power. Weighing in at 250 tons, the AN/FSQ-7 is considered the largest computer ever built. It was also considered the most reliable at the time. Only one AN/FSQ-7 operated at a time; the other was kept as a hot spare to minimize downtime. The AN/FSQ-7 was capable of executing 75,000 instructions per second, which was enough to spit out tons of radar data to 150 cathode ray tube consoles. The combat centers needed a computer like the AN/FSQ-7, but with a specialized display system; this system was named the AN/FSQ-8. The AN/FSQ-8 display console could show the status of an entire sector.