HDD history as presented at Flash Memory Summit

A presentation on the history of the hard disk drive[i] at the August 2017 Flash Memory Summit identified “key figures” in the hard disk drive industry and their “breakthroughs” – the key figures were mainly PhD’s from IBM which is not surprising given IBM’s dominance of the industry into the 1990s and the fact that the presenter was also a PhD who spent most of his career at IBM.  It wasn’t my list but it is certainly true that everyone identified made significant contributions in HDD technology, products and/or markets.

However, there were a number of incomplete facts or actual errors that need correction, including but not limited to:

  1. RAMAC 350 disk storage – The first production unit shipped in November 1957 (not 1956), it weighed less than 1 ton (not more than) and had a purchase price of $34,500 (not about $50,000) for a capacity of 5 million 6-bit characters (3.75 megabytes not 5 megabytes).
  2. Al Hoagland – Hoagland’s many accomplishments do not include responsibility for either the RAMAC head or the 1301 Disc Storage. There is no question that he was involved in both programs but according to the historical record Edward Quade[ii] was responsible for the RAMAC transducer and Al Shugart was responsible for the 1301[iii]. The RAMAC magnetic transducer was initially developed in 1953[iv] within IBM SJ’s Physics department then led by Quade.  Hoagland a professor at Berkeley did consult with Quade in the summer of 1954[v]; he became full time IBM employee in mid-1956.[vi]
  3. Al Shugart & Finis Conner – Both are well known storage executives. Shugart was not in the storage industry[vii] when it was recognized that “a hard disk drive could replace a floppy drive as a valuable, high capacity product for the emerging desktop computers.”  The first such drive, the SA1000[viii] was publically announced before Shugart reentered the industry with the founding of Seagate Technology in late 1979.    Finis Conner from his experience as a sales executive at Shugart Associates was well aware of the success of the SA1000 when he approached Shugart to found Seagate.
  4. John Squires – The actual founding of Conner Peripherals is different than presented.  Squires with the help of Terry Johnson[ix] in June 1985 formed CoData in Colorado[x] and developed the first low cost 3½-inch 40 Mbyte drive.[xi]  Advised to seek stronger marketing management, Johnson and Squires recruited the then unemployed Finis Conner[xii] which ultimately resulted in the 1986 merger of CoData into Conner’s shell corporation, Conner Peripherals, with Conner as CEO.
  5. David A. Thompson – Thompson is cited for his work in development of the thin film head which although important to IBM was less significant in an industry that continued to improve ferrite heads. Since ultimately, the thin film structure did become the writing element for magnetoresistive heads the omission of the MR head from the presentation[xiii] and Thompson’s indisputably significant work on the MR head[xiv]  was somewhat surprising.
  6. Zoned Bit Recording (ZBR) – The first ZBR products were introduced into the market in the 1960s[xv] long before 1987, the earliest filing date of the three patents cited. Apple introduced a variant on ZBR with its 400K Macintosh Floppy Disk Drive in 1984.
  7. PRML (Francois Dolivo) – The first PRML product introduced to the storage market was not the IBM disk drive in 1990 based upon Dolivo’s work, but rather the Ampex DCRS (digital cartridge recording system) in 1984 based on the work of Coleman et. al.[xvi]

Time was limited so the presenter was limited in the number of key figures he could identify.  I do think there were three key figures that should have been included:

  1. Jack Harker – Harker was actually mentioned in passing but IMO his continuing accomplishments from RAMAC to the 3380 merit individual recognition. Among them was the reduction to practice of the first air bearing head[xvii] for disk storage which was then used in the 1301 and all subsequent disk drives, albeit with further improvements.
  2. Mike Warner – Warner holds the patent[xviii] on the Winchester head, a breakthrough to a low mass, low load, close flying and low cost head which in the opinion of Al Shugart was “one of the four most significant events in the history of mass storage.[xix]” Arguably this concept remains true to date albeit with further improvements.
  3. Tu Chen – As an individual contributor and as a founder of Komag Dr. Chen was instrumental in the commercialization of sputtered media.

On the whole it was an interesting to hear one person’s view of the hard disk drive industry’s history.  Of course, mine is somewhat different.

Tom Gardner


[i]Hard Disk Drives: The Giants of the Storage Industry” Flash Memory Summit, August 10, 2017, Session 302B

[ii] [Kean] “IBM San Jose. A Quarter Century of Innovation,” David W. Kean, IBM, p.64, footnote 25

[iii] [Bashe]. “IBM’s Early Computers,” Bashe et al, MIT Press, ©1986,  p. 307

[iv] Ibid., p. 286

[v] Ibid., p. 95, Footnote 18

[vi] Ibid., p. 305

[vii] “Before starting Seagate, Mr. Shugart took a five-year hiatus from the computer industry, …,”  Alan F. Shugart, 76, a Developer of Disk Drive Industry, Dies, J Markoff, NY Times, December 15, 2006

[viii] “Winchester technology invades floppy territory with low-cost 8-in. drive,” L Yencharis, ELECTRONIC DESIGN 19, September 13, 1979, p. 70-75

[ix] Founder of MiniScribe

[x] “Disk-drive firm thinking small,” Denver Post, August 25, 1985, §B

[xi] Other low cost drives at that time used open loop stepper motor control and were unable to reliably achieve 40 Mbyte in a 3½-inch form factor

[xii] Oral History of John Squires, Computer History Museum, July 2009, p. 41-42

[xiii] Four slides (15-18)  naming four individuals jump from thin film heads to Giant Magneto Resistive heads skipping MR heads.

[xiv]MAGNETORESISTIVE (MR) HEADS,” C. Bajorek, Computer History Museum, November 2014, p. 5

[xv] Bryant Series 4000 Disc File and General Electric MRADS as cited in “Disc File Applications,” Informatics Inc., Culver City CA, © 1964

[xvi] “High data rate magnetic recording in a single channel,” Coleman, et. al., Journal of the Institution of Electronic and Radio Engineers, Vol. 55, No. 6, pp. 229-236. June 1985

[xvii] Op. cit., Bache, p.303

[xviii] U.S. Patent 3,823,416,  Michael W. Warner, July 9, 1974

[xix] See:

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