ITT Course – Unit I. Chapter 4 Auxiliary Storage Devices. Learning Objectives. To discuss various Auxiliary Storage Devices To know about Magnetic Tape, Winchester Disk, Floppy Disk, etc. To understand other storage devices like CD-ROM, CD-R Drive, etc. An Introduction. - PowerPoint PPT Presentation
ITT Course Unit I
ITT Course Unit IChapter 4Auxiliary Storage DevicesThe Institute
of Chartered Accountants of India(Setup by an Act of
Parliament)Board of Studies100 Hours ITT CourseITT Course - Unit I
--> Chapter 1 - Computer Concepts1
Learning ObjectivesTo discuss various Auxiliary Storage
DevicesTo know about Magnetic Tape, Winchester Disk, Floppy Disk,
etc.To understand other storage devices like CD-ROM, CD-R Drive,
etc.The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseITT Course - Unit
I --> Chapter 1 - Computer Concepts2An IntroductionPrimary
StorageSecondary StoragePrimary storage is directly accessible to
the CPU.The data in the secondary storage is accessed by the CPU
through intermediary devices like the processor cache. It offers a
very fast access rate. It offers slow access rate.It is highly
volatile in nature It is non volatile in nature
It is an expensive memoryIt is not an expensive memoryIt is used
to store small amount of data.It is used to store large amount of
data.Primary Storage consists of RAM, Processor Register and
Processor Cache.Secondary Storage consists of Hard Disk, Floppy
Disk, CD, DVD, Flash Drives, etc.The Institute of Chartered
Accountants of India(Setup by an Act of Parliament)Board of
Studies100 Hours ITT Course
Auxiliary Storage Device The main memory construction is costly.
Therefore, it has to be limited in size. The main memory is used to
store only those instructions and data which are to be used
immediately. However, a computer has to store a large amount of
information. The bulk of information is stored in the auxiliary
memory. Auxiliary memory is also called backing storage or
secondary storage. Auxiliary memory includes hard disk, floppy
disks, CD-ROM, USB flash drives, etc.
Hard DiskCompact DiskFlash DriveDigital Video DiskFloppy
DiskMagnetic TapeThe Institute of Chartered Accountants of
India(Setup by an Act of Parliament)Board of Studies100 Hours ITT
CourseMethods for Secondary StorageAny method for secondary storage
must involve two physical parts which is as follows:-
A peripheral device (the component of the computer which 'reads'
in or 'writes' out the information to/from the system unit,) and An
input/output medium, on which the information is actually
stored.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseSecondary Storage
Access The act of retrieving pieces of stored information is called
access. Access time is the average time taken from the device to
search and read the required data on the storage medium. Shorter
access time means higher searching speed.The Institute of Chartered
Accountants of India(Setup by an Act of Parliament)Board of
Studies100 Hours ITT CourseSequential AccessIn sequential access,
the items are traversed one by one from the beginning of the
sequence to the desired one.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseRandom AccessIn
random access, also call direct access, any item can be accessed
relatively independently of its location in the sequence.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseData Transfer
Rate Data transfer rate is the amount of data that can be
transferred between the main memory and a storage device per
second. The unit of data transfer rate is bps (bits per second).
Higher data transfer rate means faster reading / writing
process.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseReading DataSteps
for reading data from secondary storage devices is shown as
follows:-
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseWriting DataSteps
for writing data into secondary storage devices is shown as
follows:-
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT Course
Secondary Storage MediumFollowing are the mediums used as
secondary storage devices:-
Magnetic TapesMagneto-Optical DiskMagnetic DiskOptical DiskThe
Institute of Chartered Accountants of India(Setup by an Act of
Parliament)Board of Studies100 Hours ITT CourseMagnetic Tapes
Magnetic tape is the most popular and oldest storage medium used to
store large amount of data and instructions permanently. The
magnetic tape is a plastic ribbon with width 0.25 inch to 1 inch
and one side coated with magnetic recording material (ferrous-oxide
or iron-oxide), which can be magnetized. Data is stored on the tape
in the form of magnetic field, i.e. magnetized and non-magnetized
spots representing ls and 0s respectively. Tape remains a viable
alternative to disk in some situations due to its lower cost per
bit.
Small open reel of 9 track tapeThe Institute of Chartered
Accountants of India(Setup by an Act of Parliament)Board of
Studies100 Hours ITT CourseMagnetic Tapes (First Recording )
Magnetic tape was first used to record computer data in 1951 on
the Mauchly - EckertUNIVAC I. The recording medium was a 1/2 inch
wide thin band ofnickel-plated bronze. Recording density was 128
characters per inch on eight tracks at a linear speed of 100 ips,
yielding a data rate of12,800 characters per second. Making
allowance for the empty space between tape blocks, the actual
transfer rate was around 7,200 characters per second.UNIVAC I -
Tape Units, 1951The Institute of Chartered Accountants of
India(Setup by an Act of Parliament)Board of Studies100 Hours ITT
CourseMagnetic Disk A memory device, such as a floppy disk, a hard
disk, or a removable cartridge, that is covered with a magnetic
coating on which digital information is stored in the form of
microscopically small, magnetized needles. A storage device,
consisting of magnetically coated disks, on the surfaces of which
information is stored in the form of magnetic spots arranged in a
manner to represent binary data.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseTracks and
SectorsTracks and SpotsThe disk surface is divided into concentric
tracks (circles within circles). The thinner the tracks, the more
storage. The data bits are recorded as tiny magnetic spots on the
tracks. The smaller the spot, the more bits per inch and the
greater the storage.
SectorsTracks are further divided into sectors, which hold a
block of data that is read or written at one time
Tracks and SectorsTracks are concentric circles on the disk,
broken up into storage units called "sectors." The sector, which is
typically 512 bytes, is the smallest unit that can be read or
written.The Institute of Chartered Accountants of India(Setup by an
Act of Parliament)Board of Studies100 Hours ITT CourseMagnetic Disk
SummaryTechnology Still in use:- Fixed Hard Disk Floppy Disk Zip
Removable Disk REV Removable DiskDiscontinued Technology:-
PocketZip Removable Disk Jaz Removable Disk ORB Removable Disk
LS-120 Removable Disk HiFD Removable Disk SyQuest Removable Disk
SyJet Removable Disk SparQ Removable Disk EZFlyer Removable Disk
Quest Removable Disk Bernoulli Removable DiskThe Institute of
Chartered Accountants of India(Setup by an Act of Parliament)Board
of Studies100 Hours ITT CourseFloppy Disk A 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
FDD (Floppy Disk Drive).
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseFloppy Drive
(Technology)
3-inch drives Date Invented: 19828-inch drivesDate Invented:
19695-inch drives Date Invented: 1976Invented by IBM team led by
David L. NobleThe Institute of Chartered Accountants of India(Setup
by an Act of Parliament)Board of Studies100 Hours ITT CourseFloppy
Disk (Technology)3-inch disk8-inch disk5-inch disk
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT Course
Floppy Disk (Anatomy)The Institute of Chartered Accountants of
India(Setup by an Act of Parliament)Board of Studies100 Hours ITT
CourseFloppy Disk (Anatomy)
1. Write-protect tab (open=protected) 2. Hub 3. Shutter 4.
Plastic housing 5. Paper ring 6. Magnetic disk 7. Disk sector User
can see how the disk is divided into tracks (brown) and sectors
(yellow).
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseFloppy Drive
(Anatomy)
Drive Motor: A very small spindle motor engages the metal hub at
the center of the diskette, spinning it at either 300 or 360
rotations per minute (RPM).
Stepper Motor: This motor makes a precise number of stepped
revolutions to move the read/write head assembly to the proper
track position. The read/write head assembly is fastened to the
stepper motor shaft.
Mechanical Frame: A system of levers that opens the little
protective window on the diskette to allow the read/write heads to
touch the dual-sided diskette media. An external button allows the
diskette to be ejected, at which point the spring-loaded protective
window on the diskette closes. The Institute of Chartered
Accountants of India(Setup by an Act of Parliament)Board of
Studies100 Hours ITT CourseFloppy Drive (Anatomy)
Read/Write Heads: Located on both sides of a diskette, they move
together on the same assembly. The heads are not directly opposite
each other in an effort to prevent interaction between write
operations on each of the two media surfaces. The same head is used
for reading and writing, while a second, wider head is used for
erasing a track just prior to it being written. This allows the
data to be written on a wider "clean slate," without interfering
with the analog data on an adjacent track.
Circuit Board: Contains all of the electronics to handle the
data read from or written to the diskette. It also controls the
stepper-motor control circuits used to move the read/write heads to
each track, as well as the movement of the read/write heads toward
the diskette surface. The Institute of Chartered Accountants of
India(Setup by an Act of Parliament)Board of Studies100 Hours ITT
CourseHard Disk Drive A hard disk drive is a non-volatile storage
device that stores digitally encoded data on rapidly rotating
platters with magnetic surfaces. A typical desktop machine will
have a hard disk with a capacity of between 10 and 40
gigabytes.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseTypes of Hard
Disk DriveThe Institute of Chartered Accountants of India(Setup by
an Act of Parliament)Board of Studies100 Hours ITT CourseInternal
Hard Disk DriveThe internal hard disk drives are used for the
storage of the data in the computer case. There are not portable
and usually are inside the case.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseExternal Hard
Disk DriveThe external hard disk drives are portable can be
connected to other computer systems as well. There is a hard casing
over the hard disk.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseMeasuring
Performance of Hard Disk DriveThere are two ways to measure the
performance of a hard disk:
Data rate: The data rate is the number of bytes per second that
the drive can deliver to the CPU. Rates between 5 and 40 megabytes
per second are common.
Seek time: The seek time is the amount of time between when the
CPU requests a file and when the first byte of the file is sent to
the CPU. Times between 10 and 20 milliseconds are common.
The other important parameter is the capacity of the drive,
which is the number of bytes it can hold. The Institute of
Chartered Accountants of India(Setup by an Act of Parliament)Board
of Studies100 Hours ITT CourseHard Disk Drive Components
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT Course
First Hard Disk Drive
In September 1956 IBM launched the 305 RAMAC, the first computer
with a hard disk drive (HDD). The HDD weighed over a ton and stored
5 MB of data.1956: IBM 305 RAMAC Computer with Disk DriveThe
Institute of Chartered Accountants of India(Setup by an Act of
Parliament)Board of Studies100 Hours ITT CourseZip Disk and Drive
Zip disks are high capacity, removable, magnetic disks, which can
be read or written by ZIP drives. The Zip drive is a
medium-capacity removable disk storage system. It was introduced in
late 1994. ZIP disks are similar to floppy disks, except that they
are much faster, and have a much greater capacity. ZIP disks are
available in size of 100 MB, 250 MB, 750 MB. ZIP drives are
available as internal or external units using SCSI, IDE, Parallel
Port interfaces. The rewritable CDs and rewritable DVDs replaced
the Zip drive for mass storage.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseUSB Drive A
small, portable flash memory card that plugs into a computers USB
port and functions as a portable hard drive. A USB flash drive
consists of flash memory data storage device integrated with a USB
(Universal Serial Bus) interface. A flash drive consists of a small
printed circuit board carrying the circuit elements and a USB
connector, insulated electrically and protected inside a plastic,
metal, or rubberized case which can be carried in a pocket or on a
key chain. USB flash drives are often used for the same purposes as
floppy disks. USB flash drives have less storage capacity than an
external hard drive. They are smaller, faster, have thousands of
times more capacity, and are more durable and reliable. USB flash
drives also are called thumb drives, jump drives, pen drives, key
drives, tokens, or simply USB drives.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseInside USB
Drive
1 USB connector2 USB mass storage controller device3 Test
points4 Flash memory chip5 Crystal oscillator6 LED7 Write-protect
switch 8 Space for second flash memory chipThe Institute of
Chartered Accountants of India(Setup by an Act of Parliament)Board
of Studies100 Hours ITT CourseOptical Disk Optical storage devices
are the most widely used and reliable storage devices. It was
introduced in 1982. These devices use laser technology to store and
read data to and from the disk. An optical storage media consists
of a flat, round, portable metal disc, which is coated with a thin
metal or plastic or other material that is highly reflective.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT Course1st Generation
Optical DiskInitially, optical discs were used to store music and
computer software. The laser disc format stored analog video
signals.
Compact Disc (CD) Laser disc Magneto-optical disc Mini disc
DVD
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT Course2nd Generation
Optical DiskSecond-generation optical discs were for storing great
amounts of data, including broadcast-quality digital video.
Hi-MD DVD and derivatives DVD-Audio DualDisc Digital Video
Express (DIVX) Super Audio CD Video CD Super Video CD Enhanced
Versatile Disc GD-ROM DataPlay Phase-change Dual Universal Media
Disc Ultra Density Optical
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT Course3rd Generation
Optical DiskThird-generation optical discs are in development,
meant for distributing high-definition video and support greater
data storage capacities, accomplished with short-wavelength
visible-light lasers and greater numerical apertures.
Currently shipping: Blu-ray Disc HD VMD Disc CBHD Disc In
development: Forward Versatile Disc Digital Multilayer Disk /
Fluorescent Multilayer Disc Abandoned: HD DVD
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseNext Generation
Optical DiskThe following formats go beyond the current
third-generation discs and have the potential to hold more than one
terabyte (1TB) of data:
Holographic Versatile Disc LS-R Protein-coated disc
(Layer-Selection-Type Recordable Optical Disk)The Institute of
Chartered Accountants of India(Setup by an Act of Parliament)Board
of Studies100 Hours ITT CourseLens of a Compact Disk Drive
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CoursePits and Lands
The information on the optical disk is stored in the form of pits
and lands. The pits are the tiny reflective bumps that are created
with laser beam. The lands are flat areas separating the pits. A
land reflects the laser light, which is read as binary digit 1. A
pit absorbs or scatters light, which is read as binary digit 0. The
high-powered laser beam creates the pits. A lower-powered laser
light reads data from the disc. Like tracks on a magnetic disk, the
tracks of an optical disk are divided into sectors but shape of
these sectors is different than sectors of magnetic disk.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseCD-ROM CD-ROM
stands for Compact Disc Read-Only-Memory. It was introduced in
1984. CD-ROM is a type of optical disc that uses laser technology
to store and to read data to and from the disc. A large amount of
data can be stored on a single disk. Once the information is stored
on the CD-ROM, it becomes permanent and cannot be changed
(altered). The information can only be read for processing. The
CD-ROM is removable and can be used to transfer data from one
computer to another like a floppy disk. A typical CD-ROM has
storage capacity from 650 MD to 1GB.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT Course
The CD-ROM drive is used with computer to read the information
from the CD-ROM.
Today, CD-ROM drives have transfer rates (or speeds) ranging
from 48X to 75X or more. CD-ROM Drive
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseCD-R CD-R stands
for Compact Disc Recordable which is a blank disk that is used to
store information. It was introduced in 1988. The user can also
write data on an optical disc. The process of writing data on the
optical disc is called burning. A locally developed CD-R can be
used in any CD-ROM drive. It must be noted that once data is
written on the CD-R. It cannot be changed. However, a user can
store data on other part of the disk until it is full. Each part of
a CD-R can be written only one time and can be read as many times.
The CD-writer is used to write data on CD-R. The main disadvantage
of CD-R is that information can be written only once. These cannot
be overwritten and erased.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseCD-Writer A
CD-writer or recorder is used to write data on CD-R disks. Usually,
a CD-writer can read information from CD as well as write
information on CD. Today, most of the PCs have CD writer. The speed
of these drives is up to 48X or more. These drives are more
expensive than ordinary CD-ROM.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseCD-RW CD-RW
stands for compact Disc Rewritable. It was introduced in 1996. The
CD-RW is a new generation of optical disk. It is erasable disc. The
user can write and over-write data on the CD-RW disc many times.
The CD-RW acts like a floppy and hard disk that allow users to
write and re-write data. However, the reliability of the disc tends
to decrease, each time you rewrite data.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseDVD DVD stands
for Digital Video Disk. The DVD was developed in 1995. It was a
natural upgrade to the CD. The DVD capacity is 4.7 GBs for single
layer DVDs, and 8.5 GBs for dual layer DVDs. DVDs resemble Compact
Discs in that they have the exact appearance.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseDVD-ROM / DVD-R
Drive DVD stands, for Digital Video Disc or Digital Versatile Disc.
DVD-ROM is an extremely high capacity optical disc with storage
capacity from 4.7 GB to 17 GB. DVD disc is specially used to store
movie films, huge databases, music, complex software etc. The
DVD-ROM drive is used to read data from DVDs and CDs. Some DVD-ROMs
are double sided and data is stored on both sides of the disc.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseDVD-RW A DVD-RW
disc is a rewritable optical disc with equal storage capacity to a
DVD-R, typically 4.7 GB. The primary advantage of DVD- RW over
DVD-R is the ability to erase and rewrite to a DVD-RW disc.
According to Pioneer, DVD-RW discs may be written to about 1,000
times before needing replacement, making them comparable with the
CD-RW standard. DVD-RW discs are commonly used for volatile data,
such as backups or collections of files.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseDVD Writer DVD
Writer is a device which is used to read and display as well as
writer contents from / to DVD and CDs.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseDVD-RAM DVD-RAM
(DVDRandom Access Memory) is a disc specification presented in 1996
by the DVD Forum, which specifies rewritable DVD-RAM media and the
appropriate DVD writers.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseDVD+RW DVD+RW is
the name of a standard for optical discs: one of several types of
DVD, which hold up to about 4.7 GB per disc It is used for storing
films, music or other data. DVD+RW supports random write access,
which means that data can be added and removed without erasing the
whole disc and starting over (up to about 1000 times). However,
they (and DVD-RW) are less popular for computer use than DVD-R or
DVD+R discs, because they are not suitable for permanent backup
files, and because non-rewritable media is significantly cheaper.A
12 cm Sony DVD+RW shown in comparison in size to a 7.5 inches (19
cm) pencil.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseDVD+R The DVD+R
format was developed in mid 2002. DVD+R discs have 4.7 GB or 4.377
GiB (DVD-R has 4.382 GiB) of storage capacity. Unlike DVD+RW discs,
DVD+R discs can only be written to once. Because of this, DVD+R
discs are suited to applications such as nonvolatile data storage,
audio, or video.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseDVD+R DL DVD+R DL
(DL stands for Double Layer) is a derivative of the DVD+R format
created by the DVD+RW Alliance. Its use was first demonstrated in
October 2003. DVD+R DL discs employ two recordable dye layers, each
capable of storing nearly the 4.7 GB capacity of a single-layer
disc, almost doubling the total disc capacity to 8.55 GB (or 7.96
GiB). Discs can be read in many DVD devices and can only be created
using DVD+R DL and Super Multi drives.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseDVD-R DL DVD-R DL
(DL stands for Dual Layer[1]), also called DVD-R9, is a derivative
of the DVD-R format standard. DVD-R DL discs hold 8.54 GB (7.96
GiB) per side by utilizing two recordable dye layers, each capable
of storing nearly the 4.7 GB (4.38 GiB) of a single layer disc -
almost doubling the total disc capacity. Discs can be read in many
DVD devices and can only be written using DVD-R DL compatible
recorders.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseHD DVD The HD DVD
is a high density DVD which started in 2004. The HD DVD is the
successor of the DVD. It has a capacity of 15 GBs for a single
layer disk and 30GBs for a dual layer disk.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseBlu-Ray Disc
Blue-Ray disc came around in 2004. Employs a blue laser ray instead
of a red one (hence the name) which allows more precision. It has a
capacity of 25 GBs for a single layer disk and 50GBs for a dual
layer disk. The home video game console system PlayStation 3 (Sony)
is shipped with a 2x Blu-ray Disc drive.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseHolographic
Versatile Disc The Holographic Versatile Disc (HVD) is an optical
disc technology still in the research stage which would hold up to
3.9 terabytes (TB) of information which is equivalent to around 850
DVDs. It was introduced in 2004.
The Institute of Chartered Accountants of India(Setup by an Act
of Parliament)Board of Studies100 Hours ITT CourseMagneto Optical
Disc A magneto-optical drive is a kind of optical disc drive
capable of writing and rewriting data upon a magneto-optical disc.
Both 130 mm (5.25 in) and 90 mm (3.5 in) form factors exist. The
technology was introduced at the end of the 1980s.
Close up of Magneto-optical Disk surfaceThe Institute of
Chartered Accountants of India(Setup by an Act of Parliament)Board
of Studies100 Hours ITT CourseMagneto Optical Disc
2.6 GB Mangneto-Optical DiscThe Institute of Chartered
Accountants of India(Setup by an Act of Parliament)Board of
Studies100 Hours ITT Course
