FACOM 628

Drum unit, newly developed for Fujitsu's FACOM 230-25 and FACOM 230-35 mid-size general-purpose computers. The file devices available at the time were magnetic disk pack units, magnetic tape units and magnetic card units, and these were used in combination to exploit their respective advantages. Among such devices, magnetic drum units were introduced for system files, such as auxiliary memory to main memory. Because the magnetic drum units had comparatively large memory capacity, short access time, and outstanding reliability due to their mechanical characteristic.