The UNIVAC 490 was a UNIVAC computer with 16K or 32K words of magnetic-core memory. The words had 30 bits and the cycle time was 4.8 microseconds. It was a commercial derivative of the instruction set that had been developed for the AN/USQ-17 by Seymour Cray for the United States Navy. This was the last machine that Cray designed before leaving UNIVAC to join the early Control Data Corporation.
Univac Federal Systems would further develop this system into the AN/USQ-20 for the US Navy. That system was the heart of the Naval Tactical Data System which pioneered the use of shipboard computers for air defense. The military version went by a variety of names: UNIVAC 1232,[1] AN/USQ-20, MIL-1206 and CP642.