Floppy Disk (2)

8/6/2019 Floppy Disk (2)

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It is a flat carcular piece of flexiable plastics coated with magnetic oxides.It is encase in a square plastic or vinyl jecket cover.

The jecket give the handling protection to disk surfce.

They are also known as diskettes.


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Different floppy disk


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Types of Floppy DiskThere are two types of floppy disk

1 Floppy disk drive.

2 31/2-inch Floppy disk.


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Floppy disk driveAfloppy disk drive is a device used to read/write data to

a floppy disk. It is of interchaeable disk type and

allows loading/unloading of different floppy disk asand when they are used.

Speed of f loppy disk is about 300 to 400 rpm.

And data transfer rate is 10 to 30 kilobytes/second


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3-inch floppy diskIt is the most commanly used floppy disk. It is consist of

31/2-inch diameter disk encase in a square, hard -

plastic jecket cover has a cutout for read /write headto make contact with disk surface. This appear iscovered with a sliding metal piece.

All 31/2-inch f loppy disk are of double-side type record

data on the both surface.


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These type of floppy disk come in

different capacity.

1 Double density

2 High density3 Very high density


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Double density 31/2-inch disketteThe duoble density diskettes have 40 trackes 18 sector

and 512 bytes/sector giving total storage capacity for

the two surface is 720 kb.


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High Density 31/2-inch DiskettsThis diskettes have 80 trackes 18 secters and 512

bytes/sector,diving the total storage capacity is 1.4 mb.


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Very High Density 31/2-inch

diskettesThis diskettes have 80 trac

ks, 36 sectors and 512 bytes/sectors, giving the total disk

storage capacity is 2.88 mb.


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Ahard disk drive (HDD), commonly referred toas a hard drive, hard disk, or fixed disk driveis a non-volatile storage device which stores

digitally encoded data on rapidly rotating platterswith magnetic surfaces. Strictly speaking, "drive"refers to a device distinct from its medium, suchas a tape drive and its tape, or a floppy disk driveand its floppy disk.


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Histry ofHard disky HDDs (introduced in 1956 as data storage for an IBM

accounting computer were originally developed for use

with general purpose computers; see History of harddisk drives.


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y In the 21st century, applications for HDDs have expanded to

include digital video recorders, digital audio players,personal digital assistants, digital cameras and video gameconsoles.

y In 2005 the first mobile phones to include HDDs were

introduced by Samsung and Nokia.

y The need for large-scale, reliable storage, independent of aparticular device, led to the introduction of configurationssuch as RAID arrays, network attached storage (NAS)systems and storage area network (SAN) systems thatprovide efficient and reliable access to large volumes ofdata.


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TECHNOLOGYy HDDs record data by magnetizing ferromagnetic

material directionally, to represent either a 0 or a 1binary digit.

y They read the data back by detecting themagnetization of the material.y Atypical HDD design consists of a spindle which

holds one or more flat circular disks calledplatters, onto which the data are recorded.

yThe platters are made from a non-magneticmaterial, usually aluminum alloy or glass, and arecoated with a thin layer of magnetic material.Older disks used iron(III) oxide as the magneticmaterial, but current disks use a cobalt-based alloy


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AUTO FORMATING OF HARD DISK

y Amethod for auto-formating a HDD operatively attached to acomputer system is disclosed and includes the steps of:

y

(A

) effecting the CPU to read data of the FDD to determinewhether a FLAG 1 file exists in the read data;y (B) re-effecting the CPU to read data of FDD and delete

temporary files if temporary files exist in the read data;y (C) effecting the CPU to determine whether low level formatting

has been completed, to access the FDD through the FDC, and totransmit data stored in the memory to the FDD, and form a

PREFORM.YES file, if HDD has been low level formatted;y (D) storing bad track information acceptable for the capacity of

the HDD by effecting the CPU to calculate the capacity of theHDD, and determining a landing zone of the HDD;

y (E) deleting temporary files resulting when an error at step (D)exists, and renaming the FLAG 1 file to FLAG 2;


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y (F) determining the landing zone and storing a

time-converted interrupt at the predeterminedaddress of the memory by effecting the CPU tocontrol the interrupt of the timer for convertingthe interrupt of the timer into the time;

y (G) renaming the FLAG 2 file to FLAG 3, anddetermining whether the PREFORM.YES file

exists;y (H) formatting the HDD with a low level

formatting, and determining whether completedor not such that it restarts, if the formatting hasbeen done without any error;

y (I) establishing an error file, if an error hasoccurred at step (H); (J) displaying the errormessage; and, (K) ending the formattingoperation.

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Floppy Disk (2)