It has been estimated that over 200 companies were hard disk drive manufacturers at one time or another. Besides competing on features such as hard disk (HDD) data density and latencies, many of those companies started to support new, smaller form factors that enabled the ever reducing physical sizes of computing devices. Most of that industry has been reduced to a few strong vendors through bankruptcy and acquisition. As of 2007, these vendors include Seagate, Western Digital, Samsung, ExcelStor, Toshiba, Fujitsu, and Hitachi.

Here follows a list of notable defunct HDD manufacturers:

Apple, Inc. - produced the proprietary Lisa 20MB Widget drive in-house in 1984 for less than two years before getting out of the drive business.

Atasi Corp. - bankrupt

Areal Technology - acquired by Tomen Corp

Cogito Systems - bankrupt

Computer Memories Inc. (CMI) - left industry in 1986

Conner Peripherals - merged with Seagate in 1996

Conner Technologies - merged with ExcelStor in 2001

Control Data/Imprimis - hard disk drive business acquired by Seagate in 1989

Digital Equipment Corporation - hard disk drive business acquired by Quantum in 1994

Epson - left industry

IBM - hard disk drive business acquired by Hitachi in 2002

Integral Peripherals - first 1.8" rigid HDD, bankrupt in 1998

International Memories (IMI) - spun off by Memorex in 1977, left industry in 1985

Iomega - Reemerged as a company only selling cartridges for their products.

JT Storage - bankrupt in 1999

JVC - left industry

Kalok - bankrupt in 1994

Kyocera - left industry

LaPine Technologies

Maxtor - acquired by Seagate in 2006

Micropolis Corporation - bankrupt in 1997

Microscience International - bankrupt in 1992

MiniScribe - bankrupt and then acquired by Maxtor in 1990

Ministor - bankrupt in 1998

Mitsubishi - left industry

NEC - left industry

PrairieTek first 2.5" rigid HDD, bankrupt in 1991

Priam Systems - product line acquired by Prima International in 1991

Quantum Corporation - hard disk drive business acquired by Maxtor in 2000

Rahm Rotationals - renamed/merged in 1994 to Tamir Tech (purchased by Quantum 1995)

Rodime - first 3.5" rigid HDD, shut down manufacturing in 1991, licensed its patents until the patent business was sold for $1.5M in July 2003. The company was then the subject of a reverse merger and became Sportech PLC

Syquest - bankrupt in 1998, some patents acquired by

Tandon - acquired by Western Digital in 1988

Texas Instruments - left industry

Tulin Corporation - bankrupt