3. Computer…..
A computer is an electronic device that accepts raw
data, processes it according to a set of instructions and
required to produce the desired result.
4. What does a Computer Do?
The operation of every computer can be divided into
four basic functions.
Input: Information you put into the computer by way
of keyboard, mouse etc.
Processing :Also known as the "Brain" of the computer.
Processes the information you put in into human
readable form.
5. Cont……
Output: The information you put into the computer is
seen on the monitor screen and can be printers out on
paper and is readable.
Storage : Either the computers memory, CD's, DVD's,
Floppy Disc's, USB Flash Drives, etc.
6.
7. INTRODUTON OF COMPUTER
C COMMANLY
O OPERATED
M MACHINE
P PURPOSELY
U USED FOR
T TRAINING
E EDUCATION &
R RESEARCH
9. •Before the 1500s, in Europe, calculations were made
with an abacus
Invented around 500BC, available in many
cultures (China, Mesopotamia, Japan, Greece,
Rome, etc.)
•In 1642, Blaise Pascal (French mathematician,
physicist, philosopher) invented a mechanical
calculator called the Pascaline
•In 1671, Gottfried von Leibniz (German
mathematician, philosopher) extended the Pascaline to
do multiplications, divisions, square roots: the Stepped
Reckoner
None of these machines had memory, and they
required human intervention at each step
10. • In 1822 Charles Babbage (English
mathematician, philosopher), sometimes called
the “father of computing” built the Difference
Engine
• Machine designed to automate the computation
(tabulation) of polynomial functions (which are
known to be good approximations of many
useful functions)
– Based on the “method of finite difference”
– Implements some storage
• In 1833 Babbage designed the Analytical
Engine, but he died before he could build it
– It was built after his death, powered by
steam
11. HISTORY OF COMPUTERS
YEAR NAME OF
INVENTOR
NATIONALITY DEVICE /
MACHINE
1.
50
00
B.
C
ABACUS CHINESE ABACUS
2.
16
42
BLAISE
PASCAL
FRENCH MECHANICAL,
CALCULATING &
MACHINE.
3.
18
30
CHARLES
BABBAGE
ENGLISH
MATHEMATICI
AN
(U.S.)
MECHANICAL,
DIGITAL
COMPUTER,
ANALYITICAL
ENGINE.
13. Hardware Components
The term hardware refers to the physical
components of your computer such as the system unit,
mouse, keyboard, monitor etc.
Simply We Can say
o Input Devices
o Output Devices
o Storage Devices
o RAM
o ROM
14. Software Components
The software is the instructions that makes the
computer work. Software is held either on your
computers hard disk, CD-ROM, DVD or on a diskette
(floppy disk) and is loaded (i.e. copied) from the disk
into the computers RAM (Random Access Memory), as
and when required.
15. Input Devices "How to tell it
what to do“
A keyboard and mouse are the standard way to
interact with the computer. Other devices include
scanner, Tracker Ball, Touch Pads, Joystick.
16. Output Devices "How it
shows you what it is doing"
The monitor (the screen) is how the computer sends
information back to you. Other Devices includes
Printers, LCD Screens, Plotters, Speakers.
17. Storage Devices "How it saves data
and programs“
Hard disk drives are an internal, higher capacity drive
which also stores the operating system which runs
when you power on the computer.
18. RAM
RAM stands for Random Access Memory.
It is the part of main memory where data and program
instructions are held while being manipulated or executed
[44].
It is also known as Read and Write Memory.
It is a volatile (temporary) memory of computer system
and stores the data as long as the computer is on.
Once the computer is turned off, the contents (data) of
the RAM are washed out. RAM is divided into two
categories
19. RAM Categories
DRAM
DRAM stands for Dynamic Random Access Memory. It is
combination of cells that store data as charge on capacitors.
It is simpler and smaller but storage capacity is high and
hence used for large memory requirements.
SRAM
SRAM stands for Static Random Access Memory. In SRAM,
binary values are stored using traditional flip-flops logic-gate
configuration. It is faster then DRAM but its storage capacity
is less.
20. ROM
ROM stands for Read Only Memory. As the name
implies, the contents of ROM can only be read. Data
cannot be written into read-only memory. ROM may
contain the information on how to start the computer
and even instructions to the entire operating system
It is a permanent memory of computer and user
cannot change it contents
21. Processing Unit(CPU
Hardware Component)
The processing unit is the most important and
powerful part of computer system. It is the heart of
computer system. All calculations and other operations
are performed in this unit
22. Functions of Processing Unit
Accepts data or instructions from input unit and stores
them in memory.
Stores intermediate and final result of processing.
Interprets (translate) or manipulate the instruction and
send commands to relevant units.
Does all arithmetic operations on the data i.e. addition,
subtraction, multiplication, division etc.
Does all logical and decision-making operations on data,
i.e. comparison of data.
Sends the result to the output devices when required.
23. Central Processing Unit -CPU
Consist of
CU (control Unit)
ALU (Arithmetic & logic Unit)
Registers
24. Control Unit
It is the most important part of the CPU. It controls and
coordinates the activities of all other units. It performs this
function by issuing necessary commands to various
components of the computer.
The control unit fetches an instruction from the main
memory by sending an address to main memory, decode
this instruction and then execute it. Thus we can say that
CU’s function is to fetch, decode and then finally execute
the instructions, which are in main memory.
OR
The control unit interprets any instructions it receives from
memory and directs the sequence of events necessary to
execute each instruction. The control unit also establishes
the timing of these events.
25. Arithmetic and logic unit
All the arithmetical and logical activities are performed
in the ALU. It is the place where all calculations are
performed and all decisions are made. The data is
temporarily transferred to ALU for processing and
results are sent back to memory.
The ALU perform all the arithmetic operations such as
Addition, Subtraction, Multiplication or Division and
Logic operations such as the operations in which first
comparison is made and then decision is taken
26. Registers
The processor contains special storage locations called
registers. These are temporary storage devices and all
the data is temporarily stored in them before and after
processing.
27.
28. How Computer Memory
Measured?
Bit
All computers work on a binary Numbering system, i.e. they process data in one's
or zero's. This 1 or 0 level of storage is called a bit.
o Byte
A byte consist of 8 bits.
o Kilobyte
A Kilobyte(KB) consists of 1024 bytes
o Megabyte
A Megabyte (MB) consists of 1024 Kilobytes
o Gigabyte
A Gigabyte (GB) consists of 1024 Megabytes
o Terabyte
A Terabyte Consist of 1024 Gigabytes
29. How Does a Computer Know
what to do?
It must be given a detailed list of instructions, called a
compute program or software, that tells it exactly what
to do.
Before processing a specific job, the computer
program corresponding to that job must be stored in
memory.
Once the program is stored in memory the compute
can start the operation by executing the program
instructions one after the other.
