1968: Memorex Introduces an IBM compatible HDD

Plug-compatible (PCM) disk-drive manufacturers proliferate

Founded in 1961 by Laurence L (Larry) Spitters and others from Ampex to produce professional magnetic tape media, in 1966 Memorex Corporation, Santa Clara, CA became the first independent manufacturer of removable disk packs. The company introduced the Memorex 630, an IBM 2311 plug-compatible disk drive, in 1968. Memorex sold the 630 to end users of IBM mainframes and connected to their systems thru an IBM 2841 storage control unit. This encouraged other vendors to enter the IBM plug-compatible manufacturer (PCM) disk drive market, including Ampex, Century Data, Control Data Corporation, Information Storage Systems (ISS), Marshall, Potter Instruments, and Telex.

Headed by Ken Fannin, key engineers on the 630 project included Dave Jepson (recording), Joseph Moos (servo) and John Richards (electronics). Roy Applequist recommended a voice coil actuator over the hydraulic motor of the 2311. It's seek time was substantially faster than the 2311 and because of fewer mechanical parts it was marketed as being more reliable. In 1969, Memorex introduced the higher capacity 660 drive (plug-compatible with the IBM 2314). Memorex then partnered with Digital Equipment Corporation (DEC) to create a DEC-interface version of the Memorex 630, called the RP01, and of the Memorex 660, called the RP02.

Burroughs, called Unisys after a 1986 merger with Univac, acquired Memorex in 1981. Now owned by Imation, the Memorex name survives as a consumer tape brand made famous by a 1972 TV advertizing campaign of jazz singer Ella Fitzgerald‘s voice shattering a glass - ''Is it live or is it Memorex?''

  • Applequist, Roy A., Wilson, Laurence M. “Magnetic Recording Disc Drive with Head Positioning and Collision Avoidance Apparatus” U.S. Patent 3,544,980 (Filed: Mar 22, 1968 Issued: Dec 1, 1970)

Rev: 9.19.18