Based on materials from "Radio" magazines.
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Flexible magnetic disks.
A little history.
The first floppy magnetic disks (FMD), or
as they are also called floppy disks, and so-
the floppy disks had a diameter of 8 inches
(2O3mm) and first allowed recording
The data is only on one side. As
development of technology for manufacturing magic
thread layer and improving the mechanical
nisms of disk drives, the diameter of the GMD decreased -
sya, and their capacity increased. Next
the disk modification had a diameter of 5.25
inch (133mm). The first unilateral mo-
Delhi had a capacity of only1bOKbyte.
Soon the magnetic layer began to be applied to
both sides of the floppy disk and place a magnetic
write/read heads (MG) on both
herside-capacity increased to
ZbOKbyte.Improving MG and magnetic
greater disk coverage allowed to increase
number of tracks from4O to 8Oand density
pisi-now there is 15 on the track
sectors. The total capacity of an S-inch disk is
you have reached 1.2 MB(with the capacity of each
one sector 512 bytes).
The next stage was the change
case designs and diameter reduction
floppy disks up to3.5 inches (89mm).Hard plastic
teak case with shutter, closure
working surface of the disk, significantly
improved the security of the magnetic layer
and, therefore, data safety. I eat-
the bone of the floppy disk reached 1,HHMbyte.Mecha-
low floppy disk drive (floppy drive) also
became significantly smaller in size, and
energy consumption has decreased so much
that drives 3.5 inch floppy disks have become
are indispensable in compact computers with
battery and combined power supply.More recently, recording density
doubled again and the formatting capacity
The bathroom floppy reached 2.88 MB. B
connection with the expansion of the use of "knee-
new"Laptop computers even appeared
floppy disks with a diameter of 2 inches (51mm)
bone 72O KB. Their future, however, is still
not defined.Most common
floppy disk formats are shown in the table.
diameter number number number capacity designation
inch sides sects. dear. Kbyte start
5.25 1 8/9 4O 16O/ SD
18O
5.25 2 9 4O 36O DD
5.25 2 9 8O 72O QD
5.25 2 15 8O 128O HD 3.5 2 9 8O 72O DD
3.5 2 18 8O 144O HD
3.5 2 36 8O 288O ED
On packaging boxes you can find
symbols of floppy disk type, for example-
measures: 5.25''DS/DD 48 TPI. Quotes indicate
they look for an inch The first two letters show
that the floppy disk is double-sided, the following two
letters - recording density, in this case
"double density" (Double Density),
48-number of tracks per inch (TPI-TracK Reg
Inch).
4O tracks 5.25-inch disk corresponding to
Density48 TPI;8Opaths -96
3.5 2 18 8O 144O HD 3.5 2 36 8O 288O ED
On packaging boxes you can find
symbols of floppy disk type, for example-
measures: 5.25''DS/DD 48 TPI. Quotes indicate
look inch The first two letters show
that the floppy disk is double-sided, the following two
letters - recording density, in this case
"double density" (Double Density),
48-number of tracks per inch (TPI-TracK Reg
Inch).
4O tracks 5.25-inch disk corresponding to
Density48 TPI;8Opaths -96
TPI.
Magazine "Radio" N5, 92, pp. 25-26.
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