In 1967, IBM began developing a drive that led to the creation of the world’s first floppy disk (diskette) and disk drive. It was commercially introduced in 1971 in an 8-inch (20 cm) read-only format. The inspiration came from the flexible magnetic disk used by Telefunken in its "Plattendiktiergerät Traveller" from 1959.
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| Left to right: 8-inch, 5.25-inch and 3.5-inch floppy disk |
A diskette is divided into tracks (radially) and sectors (angularly), whereas the Telefunken disk featured gramophone-like grooves. The first read-write floppy disk drive was the Memorex 650, introduced in 1972. Various storage capacities were available in the early years due to a lack of standardisation, a situation that persisted until the later years of the third generation (3.5-inch) floppy disks.
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| Telefunken "Plattendiktiergerät Traveller" 1959 |
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| Telefunken "Plattendiktiergerät Traveller" disc 1959 |
Properties of he IBM standard format
- disk diameter 20 cm (8-inch).
- SD (single density) with 250 kbit/s data rate or / DD (double density) with 500 kbit/s data rate
- 360 rpm (revolutions per minute)
- 26 sectors/track; 73 data tracks, 1 index track, 2 spare tracks, 1 reserved track
- 128 bytes/sector
- total disk capacity 3203128 bits (242944 bytes of data with this format)
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| Left to right: 8-inch, 5.25-inch and 3.5-inch floppy disk drives |
Trivia
- In late 1976, the 5.25-inch floppy disk and disk drive were introduced to the market by Shugart Associates.
- The first 3.5-inch diskette was introduced by Sony in 1981.
