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X - inch drives, 76 or 77 tracks: track 0 on outer circumference, track 77 near hub.
track bit density, innermost track (76 or 77)
3200-3600 bpi for single density,
6400-6500 bpi for double density
rotation speed 360 RPM; track density 48 tpi (tracks per inch)
track width: .012 inches (Shugart) .013 inches (Siemens)
Track erase width: about .006 inches either side of width
track interval: .0208 inches (siemens)
data frequency
250Kbps, FM single density ; 500Kbps, MFM double density
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In life few of the things grow faster than others and there are few which gets antiquate much faster. When Computers were first used, they were so big in size – then the data media was unwieldy. In fact the 3.5” floppy disk introduced by Sony in 1981 was considered such a novelty mainly because it could be carried out in pocket. It could contain vast data of 1.44 mb – hailed as marvel ! Strange ? Life those days was not all that easy. Opening directories, creating files, renaming them, saving info – all were considered work of skilled persons and novices would look with wonder. What is done in Excel sheets were earlier performed with great difficulty in Lotus 123.
Now a days people hardly use floppy drive and many computers do not have one on them. With blue ray DVDs, pen drives and external hard disks – you can store the whole data of an office and obviously floppy disks have lost then relevance. Still, Sony had demand of 12 million 3.5” floppy disks in Japan last year alone – presumably to die-hard old schoolers.
For those who are not techno-savvy, floppy disk is a data storage medium that is composed of a disk of thin, flexible ("floppy") magnetic storage medium encased in a square or rectangular plastic shell. Floppy disks are read and written by a floppy disk drive. . Invented by IBM, floppy disks in 8-inch (203 mm), 51⁄4 in (133 mm), and 31⁄2 in (89 mm) formats enjoyed nearly three decades as a popular and ubiquitous form of data storage and exchange, from the mid-1970s to late 90s.
Information was recorded in floppy disks and for transporting them, we had the floppy disk mailer. In fact there was something known as boot disks, which helped Computers with DOS start their operation. These disks could get corrupt easily and the whole information contained therein could be lost. Still it was a owner’s pride and people carried them in shirt pockets to be seen by everybody else to be recognised as someone who is a master technician (somebody could handle computers). The diskette had a cover or sleeve or envelope, in which there was a circular disk of plastic covered with a magnetic coating inside. The inner disk was referred as a "doughnut"; the disk material called "the media". Probably our EEI policy still refers to that as “External data media”, though this could similarly apply to all other forms of storage of data.
Technically, data got written on the disk by the write head which wrote data track, which was followed by a "tunnel erase" pair of heads to erase data on either side of the data track. Disks functioned by spin at some rotational speed of a read/write head. The head was placed some distance from the center of rotation so the actual radial speed of the media, and therefore the density of flux changes or bits per radial inch of the media, varied. Corruption of data occurred when the tracks were too close together.
The first disk was introduced by IBM in 1971 and was of 8” flexible plastic disk coated with magnetic iron oxide. Because of its flexibity, it had the nickname floppy and was considered a revolutionary idea at that point of time. It was the brainchild of IBM engineers led by Alan Shugart. Further innovation ensured reduction of size to 5 ¼”. By 1978 more than 10 manufacturers were producing 5 1/4" floppy drives that stored up to 1.2MB (megabytes) of data. Then came the pathbreaking 3 1/2-inch Floppy Disk, introduced by Sony in 1981. They stored 400kb of data, and later 720K (double-density) and 1.44MB (high-density).
Representing the immortal lines of Alfred Lord Tennyson “the old order changeth, yielding place to new, and God fulfils Himself in many ways, Lest one good custom should corrupt the world”, they floppies were replaced by recordable Compact Discs, DVDs, flash drives and more.
Signalling natural death, Sony has decided to withdraw floppy disks from the market in another year from now. The move was necessitated by large capacity storage devices and other domestic manufacturers have already pulled out of the market. The epitaph is already written on a product that was so popular with the users even a decade ago.
With regards – S Sampathkumar.
PS : the one at the start is the hot chart information for 8” floppy.
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