1976: Minicomputers stimulate floppy disk sales
5.25 and 3.5-inch drives and media meet personal computer needs




Alan (Al) Shugart former DASD project manager at IBM, San Jose, who had joined Memorex in 1969, founded Shugart Associates (SA) in 1973 to build a small business computer. Shugart left before completing the project but a key component of the planned system survived as an 8-inch floppy disk drive that was introduced in 1975.
In response to a request for a lower-cost drive from Wang Laboratories, the company announced a 5.25-inch drive in 1976. The SA 400 “Minifloppy” 110 KB drive sold to OEM customers for $390 plus $45 for ten diskettes. Digital Research Inc. ported the CP/M operating system to the new smaller disk size and helped to establish the SA 400 as a popular solution for small business and personal computers. In the early 1980s, Shugart Associates, by then owned by Xerox, contracted with Matsushita for high-volume manufacturing. Matsushita received rights to sell to others and became the world’s largest floppy drive producer. Another standard emerged in 1979 when a team led by Larry Boucher (later founder of Adaptec) developed the "Shugart Associates System Interface" (SASI) that subsequently evolved into the SCSI (Small Computer System Interface).
Demand for a more robust diskette package and smaller enclosure resulted in competing formats ranging from 3.5 to 2 inches. In 1982, the Microfloppy Industry Committee agreed on a 3.5-inch specification based on a Sony design that ignited an international scramble by vendors to serve the growing PC market. Although now enclosed in a stiff outer case and with up to 1.44 MB capacity, the floppy name continued to be used. In 1994 Iomega, San Diego, CA introduced the ZIP drive that stored 100 MB on 3.5 inch removable "superfloppy" disk cartridges. By the end of the decade, Zip drives and disks became one of the most popular after market PC peripheral purchases. The floppy drive manufacturing business peaked in 1990 at around 120 million units per year before declining in favor of recordable compact disks.
Contemporary Documents
- Sollman, G. “Evolution of the Minifloppy (TM) product family,” IEEE Transactions on Magnetics (Vol: 14, Issue: 4 July 1978) pp. 160-166
- Sollman, G.H. “Double-sided Recording-the Floppy Disk Reaches Maturity” COMPCON Fall 1977 pp: 116-123
- "SA400 Minifloppy data sheet" Shugart Associates (August 1976)
- Radman et al., "Flexible-Disk Cartridge Drives Combine Reliable Operation, Removability," Computer Technology Review, (Summer 1984) pp. 77-81
More Information
- “Floppy Disks” Revolution Exhibit Computer History Museum (2011)
- Noble, David L. “Data Storage on Floppy Disks” in Eric D Daniel, C. Denis Mee, Mark H. Clark eds. Magnetic Recording: The First 100 Years, IEEE Press (1999) p. 300
- “The Floppy Disk” (Retrieved on 1.12.15 from: http://www-http://www-03.ibm.com/ibm/history/ibm100/us/en/icons/floppy/)
- “Alan Shugart: About the Floppy Disk” Video (Retrieved on 1.12.15 from: http://www-http://www.computerhistory.org/revolution/memory-storage/8/261/2276)
- “Milestones: The CP/M Microcomputer Operating System, 1974” (Retrieved 12.28.14 on from: http://www.ieeeghn.org/wiki/index.php/Milestones:The_CP/M_Microcomputer_Operating_System,_1974)
- Schoenherr, Steven. "History of Magnetic Recording" presented at IEEE Magnetics Society Seminar, UCSD (Nov. 5, 2002) (Retrieved on 11.5.14 from: http://www.aes.org/aeshc/docs/recording.technology.history/magnetic4.html)
- Schoenherr, Steven. "The Floppy Disk" in John L. Heilbron, ed., The Oxford Companion to the History of Modern Science, New York: Oxford University Press, 2003.
- “Milestones: Toshiba T1100, a Pioneering Contribution to the Development of Laptop PC, 1985” Engineering and Technology History Wiki (Retrieved on 4.2.15 from: http://ethw.org/Milestones:Toshiba_T1100,_a_Pioneering_Contribution_to_the_Development_of_Laptop_PC,_1985)
- Hertzfeld, Andy. “Quick, Hide In This Closet!” Folklore (August 1983) (Retrieved on 1.29.15 from: http://www.folklore.org/StoryView.py?project=Macintosh&story=Hide_Under_This_Desk.txt&topic=Hardware%20Design&sortOrder=Sort%20by%20Date&detail=medium)
Oral Histories
- “International Business Machines Corporation (IBM) 5.25 and 3.5 inch floppy drives oral history panel“ Computer History Museum Oral History # 102657925 (2005-01-13)
- “International Business Machines Corporation (IBM) 8 inch floppy disk drives oral history panel” Computer History Museum Oral History # 102657926 (2005-05-17)
- “Sanders, W. Ferrell oral history” Computer History Museum Oral History # 102738700 (2018-01-12)
1976_Floppy2_v4 Rev: 9.19.18