Which was an early mainframe computer?

UNIC (Universal Automatic Computer) was a mainframe computer developed by the U.S. Navy. It was completed in 1950 and was used for a variety of scientific and engineering calculations.

FUNTRIA (Fundamental Theory Research Institute Automatic Computer) was a mainframe computer developed by the Soviet Union. It was completed in 1956 and was used for a variety of scientific and engineering calculations.

BRAINIA (Brainiac) was a mainframe computer developed by the U.S. Air Force. It was completed in 1956 and was used for a variety of scientific and engineering calculations.

ENIAC was the first general-purpose electronic computer, and it was used for a variety of scientific and engineering calculations. UNIC, FUNTRIA, and BRAINIA were also mainframe computers, but they were developed later than ENIAC and were not as widely used.