The first use of core was in the Whirlwind computer, and Project Whirlwind's "most famous contribution was the random-access, magnetic core storage feature." Commercialization followed quickly. Jacobs Instrument Company used its own refined coincident-current magnetic core in its JAINCOMP series of powerful mini-computers starting in 1951. The JAINCOMP-B1, a desktop-sized unit weighing only 110 lbs and using a mere 300 subminiature vacuum tubes, could produce results rivaling the then typically room-sized institutional computers being built by universities and large scale private contractors. Magnetic core was used in peripherals of the IBM 702 delivered in July 1955, and later in the 702 itself. The IBM 704 (1954) and the Ferranti Mercury (1957) used magnetic-core memory.