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1024 Kilo Bytes
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1 Mega Bytes (MB)
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1024 Mega Bytes
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1 Giga Bytes (GB)
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1024 Giga Bytes
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1 Tetra Bytes (TB)
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1024 Tetra Bytes
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1 Peta Bytes (PB)
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1024 Peta Bytes
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1 Exa Bytes (EB)
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1024 Exa Bytes
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1 Zotta Bytes (ZB)
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1024 Zotta Bytes
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1 Yotta Bytes (YB)
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The memory unit is called by
different names, such as storage, internal storage or main memory. The two
types of storage in the computers system are called.
- PRIMARY
STORAGE 2. SECONDARY STORAGE
1) PRIMARY
STORAGE:
The memory unit, which is inside the “C.P.U”, is known as the
primary storage. It stores the data entire in the system and also stores the
information resized after the processing. The following are the different types
of primary memory.
A. RAM (Random Access Memory)
B. ROM (Read Only Memory)
A) RAM:
Under this type of memory, programs / data are stored only as long as the power
is ON. It is a read/write memory. I.e. information may be written onto, read
from it. “Ram” is stored temporary, and is lost when it is powered OFF. It is
also called Volatile Memory.
B) ROM:
This type of memory is permanently loaded by the manufacturer. It cannot be
changed or erased by the user. This memory is also known as Non-Volatile Memory
and Permanent Memory.
II. CONTROL
UNIT (CU): -
This is the Central Nervous System of the computer. It controls
maintains order and directs the operation of the entire system. During
execution they are transferred one by one to the Control unit for execution the
controlling of entire computer system. It is the part of C.P.U. it act as a
manager of the computer and also called “HEART” of the computer. Example of the
instructions is for reading the data it gets executed through the input device.
III. ARITHMATIC
LOGICAL UNIT (A L U): -
The A.L.U. is stand for Arithmetic Logical Unit is responsible for
mathematical calculations. It perform Addition, Subtraction, Division logical
comparisons (such as A > B) on the data sent it from the memory. The ALU
contains one or more storage locations “Registers”. Generally the result is
also produced in a register.
2) SECONDARY
STORAGE:
Secondary storage is an area of storage separate from
the main memory, mostly used for long term storage. Secondary storage devices
are used to permanently store programs / data. Example: - Floppy, C.D, s &
DVD’s etc
A) FLOPPY DISK:
A
Floppy disk is a flexible plastic disk coded with magnetic oxide and enclosed
with in a plastic or card board sleeve. Floppy is come into two types of
Densities. Single Density and Double Density. Today the most commonly used
floppy is “3.5” inches with “High Density”. This floppy also called
“Micro-Floppy”. The storage capacity is 1.44 M.B. But now a days nobody can
used floppy’s. (Outdated).
B) HARD
DISK:-
Hard disk is much faster than floppy disk. This is a sealed disk
pack containing magnetic coated surfaces to record information. This is also
called “Winchester
C) COMPACT
DISK - Read Only Memory (CD-ROM): -
Compact is the latest high
reliabilities low cost memory media. The C.D used the laser technology to read
and write the information. The major advantage of CD is that its portable and
the data reliability are very high information can be stored up to 700 MB.
D) DVD
(Digital Video Disk):- Compact is the latest high reliabilities low cost
memory media. The major advantage of DVD is that its portable and the data
reliability are very high information can be stored up to 4.7 GB.
OUT PUT DIVICES
Data and programs that are
stored in memory as electrical charges have to be performing called Output
Devices. Common output devices are VDU and Printers.
1) MONITER:
-
The Visual Display Unit also called the “V.D.U” Uses what is called a Cathode
Ray Tub [C.R.T] to display information. It looks like a television screen. A
maximum of 24 rows and 80 columns per row of information can be displayed in
the text mode. Monitor also called with another name “Soft Copy”.
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