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.

  • 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

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