Talk:Creating Magnetic Disk Storage at IBM

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Correcting the history of "flying" slider technology022:00, 10 July 2015

Correcting the history of "flying" slider technology

The article in its discussion of "slider technology" cites the date of the Noyes and Dickinson “Engineering Design of a Magnetic-Disk Random-Access Memory” article as 1952; it was actually February 1956. The slider technology therein was the prior art air loaded slider of the RAMAC era rather than the modern "flying" slider technology used in all subsequent disk drives. Perhaps more relevant to competition's adoption of "flying" slider technology are the three articles "“A Gas Film Lubrication Study - Parts I, II and III " published in the July 1959 IBM Journal of Research and Development. Al Shugart much later described the 1959 publication as “Besides giving all the information on how to do the thing, they gave them all the data of spacer and load that they took. So companies like Bryant, Computer Products, Telex and a few others started implementing slider bearing heads using the IBM Journal of Research data.” [Stevens, et al., The Disk Drive Story Chapter 1: IBM's RAMAC, Transcript #3, January 11, 2002, IBM SJ, Computer History Museum catalog number 102739924]

To Shugart’s list of competitors I would add Librascope who in 1962 disclosed their flying head hard disk drive in their L-2010 portable computer and offered it in 1963 in a family of OEM products, the L100 and L200 series

The article further credits the IBM 1301 disk storage which shipped in 4Q 1962 as the first IBM product with flying “slider technology.” The Model 353 disk storage (called the Stretch drive during development) used the same "flying" slider technology with production units shipping about one year before the 1301 to Lawrence Livermore Laboratory with the second 7030 (Stretch) computer. Many have confused a prototype Stretch disk file shipped in 1960 using air loaded slider technology (RAMAC heads) with the later production Model 353 units using “flying" slider technology. This prototype Stretch drive was a one-of-a-kind which was replaced by a 353. The 353 and the 1301 were very similar sharing most components and, both coming out of the IBM program internally designated ADF for Advanced Disk File.

The IBM 1301 disk storage was by far the most successful of these first "flying" slider technology drives and it, like the IBM 353 disk storage was a product of the inventors first implementing and disclosing this technology, but it was not the first such drive.

Tom94022 (talk)22:00, 10 July 2015