1. Topics
• What is computer
• Information processing cycle
• Computer system
• Types of computer
• Generations of computer
• Uses of computer
• Importance of computer
• Limitations of computer
2. What is computer
• Computer - An electronic device used to process data.
• A computer is a general purpose device that can be
programmed to carry out a set of arithmetic or logical
operations automatically.
• Consists of central processing unit (CPU) and memory.
• CPU: It can execute a prerecorded list of instructions (a
program).
• Memory: It can quickly store and retrieve large amounts of
data.
5. Functionalities of a computer
Any digital computer carries out five functions in gross terms:
• Input: Takes data as input.
• Store: Stores the data/instructions in its memory and use them when
required.
• Process: Processes the data and converts it into useful information.
• Output: Generates the output
• Control: Controls all the above four steps.
6. • Hardware - Physical parts of the computer
• Software – Sequence of instructions to the computer
• Data - Raw facts the computer can manipulate
• People – Can be system analyst, programmer, computer
operator
Computer System
8. Any part of the computer you can touch. It consists of
interconnected electronic devices.
• Processor
• Memory
• Input and Output Devices
• Storage Devices
Hardware
10. •Brain of computer
•A processor is an integrated electronic circuit that
performs the calculations that run a computer.
•A processor performs arithmetical, logical, input/output
(I/O) and other basic instructions that are passed from an
operating system (OS).
•Most other processes are dependent on the operations of
a processor.It is placed into the motherboard
•Speed is controlled by system clock
•Speed is measured by MHz, GHz etc.
Processor
11. •Consists of one/more chips
•Stores data and/ or programs
•Example: RAM & ROM
•The CPU can find any piece of data in RAM, when it needs
it for processing.
Memory
12. • Input devices accept data and instructions from the
user or from another computer system. The
keyboard and mouse are examples of input devices.
• Output devices return processed data back to the
user or to another computer system. The printer and
monitor are examples.
• Communications devices (such as modems and
network interface cards) perform both input and
output, allowing computers to share information.
Input and Output Devices
13. • Storage devices hold data not currently being used
by the CPU.
• 2 types of storage: magnetic & optical disk. Each
type uses a special medium for storing data on its
surface.
• A disk drive is a device that reads data from and
writes data to a disk. Magnetic Disk: floppy disk
drive, hard disk drive
• The most common optical storage devices are CD-
ROM and DVD-ROM drives.
Storage Devices
15. Sequence of instructions which directs a computer to
perform certain functions. Also known as programs.
2 types of software:
• System Software
• Application Software
Software
16. Consists of programs that help to use a computer.
Tasks:
•Organizing and maintaining data files
•Translating programs
•Scheduling jobs
Example:
❑Operating Systems
• Windows 10
• Windows 7
• Linux
❑Network Operating System
❑Disk Utilities
System Software
17. Application Software
• Word Processing
• Spreadsheets
• Graphics
• Databases
• Entertainment
• Educational
• Communications
• Presentation
Performs user applications.
Tasks:
•Performs a particular type of task
19. System vs. Application Software
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• System software gets installed when the operating system is installed on the
computer while application software is installed according to the requirements of the
user.
• System software includes programs such as compilers, debuggers, drivers,
assemblers while application software includes media players, word processors, and
spreadsheet programs.
• System software does not depend on application software but application software
depends on system software.
• A computer may not require more than one type of system software while there
may be a number of application software programs installed on the computer at the
same time.
• System software can run independently of the application software while
application software cannot run without the presence of the system software.
20. Data
4/26/2018
• Data consists of raw facts, which the computer can
manipulate and process into information that is
useful to people.
• Computerized data is digital, meaning that it has
been reduced to digits, or numbers. The computer
stores and reads all data as numbers.
• Although computers use data in digital form, they
convert data into forms that people can understand,
such as text, numerals, sounds, and images.
21. • People are the computer's operators, or users.
• Some types of computers can operate without much
intervention from people, but personal computers
are designed specifically for use by people.
User
22. Types of computer
Computers can be generally classified by size and power as
follows, though there is considerable overlap:
• Personal computer
• Workstation
• Minicomputer
• Mainframe
• Supercomputer
23. Types of computer
• PC (Personal Computer)-It is a single user computer system having
moderately powerful microprocessor
• WorkStation-It is also a single user computer system which is similar to
personal computer but have more powerful microprocessor.
• Mini Computer-It is a midsize multi-processing system capable of supporting
up to 250 users simultaneously.
• Main Frame-Mainframe is very large in size and is an expensive computer
capable of supporting hundreds or even thousands of users simultaneously.
• Supercomputer-It is an extremely fast computer which can execute
hundreds of millions of instructions per second.
24. PC
• A PC can be defined as a small, relatively
inexpensive computer designed for an
individual user. PCs are based on the
microprocessor technology that enables
manufacturers to put an entire CPU on one
chip.
• Designed to be used by single person
• Also known as microcomputers
• Businesses use personal computers for
word processing, accounting, and for
running spreadsheet and database
management applications. At home, the
most popular use for personal computers is
playing games and surfing Internet.
25. Workstation
• Workstation is a computer used for
engineering applications (CAD/CAM),
software development, and other such
types of applications which require a
moderate amount of computing power
and relatively high quality graphics
capabilities.
• Workstations generally come with a large,
high-resolution graphics screen, large
amount of RAM, inbuilt network support,
and a graphical user interface.
26. Minicomputer
• A minicomputer, is a class of smaller
computers that developed in the mid-
1960s.It uses in database management,
business transactions and various file
handling.
• Got this name because of their size
compared to other computers.
• Can handle much more I/O than PC
• Size and capability: between Micro
computer & Mainframe computer
• It is a midsize multi-processing system
capable of supporting up to 250 users
simultaneously.
27. Mainframe
• Mainframe is very large in size
and is an expensive computer
capable of supporting
hundreds or even thousands
of users simultaneously.
• Processes bulk data. Such as
census data, Bank data.
• Mainframe executes many
programs concurrently and
supports many simultaneous
execution of programs. It is
used in telecommunication.
28. Super computer
• Supercomputers are one of the fastest
computers currently available.
• Supercomputers are very expensive
and are employed for specialized
applications that require immense
amount of mathematical calculations.
• For example, weather forecasting,
scientific simulations, (animated)
graphics, nuclear energy research,
electronic design, mapping human
genome and analysis of geological data.
29. Generations of computer
• First Generation
The period of first generation: 1946-1959. Vacuum tube based.
• Second Generation
The period of second generation: 1959-1965. Transistor based.
• Third Generation
The period of third generation: 1965-1971. Integrated Circuit
based.
• Fourth Generation
The period of fourth generation: 1971-1980. VLSI microprocessor
based.
• Fifth Generation
The period of fifth generation: 1980-onwards. ULSI
microprocessor based
30. First generation
Time period: 1946-1959
• Vacuum tube technology: Used as
circuitry & for storage
• Very costly
• Unreliable cause of breakdown &
inefficient operation
• Supported machine language only
• Generated lot of heat
• Slow input and output devices
• Huge size
• Example: ENIAC,EDVAC,UNIVAC,IBM-
701,IBM-650
31. Second generation
Time period: 1959-1965
• Use of transistors
• Reliable in comparison to first generation
computers
• Smaller size as compared to first
generation computers
• Generated less heat as compared to first
generation computers
• Consumed less electricity as compared to
first generation computers
• Faster than first generation computers
• Example: IBM 1620,IBM 7094,CDC
1604,CDC 3600,UNIVAC 1108
32. Third generation
Time period: 1965-1971
• IC used
• More reliable in comparison
to previous two generations
• Smaller size
• Generated less heat
• Faster
• Lesser maintenance
• Example: IBM-360
series,Honeywell-6000
series
33. Fourth generation
Time period: 1971-1980
• VLSI technology used
• Very cheap
• Portable and reliable
• Use of PC's
• Very small size
• Internet introduced
• Example: STAR 1000
,PDP 11,CRAY-1(Super
Computer)
34. Fifth generation
Time period: 1980-till date.
• ULSI technology
• Development of true artificial
intelligence
• Development of Natural language
processing
• Advancement in Parallel Processing
• More user friendly interfaces
• Availability of very powerful and
compact computers at cheaper rates
• Example: Desktop, Laptop, Notebook,
Ultra Book, Chrome Book
35. Uses of computer
• Bank
• Health & Medical
• Education
• Business
• Recreation and Entertainment
• Government
• Defense etc.
36. Advantages of computer
• Volume of data: Can handle large amount of data
• Accuracy: Ensures high degree of accuracy
• Repetitiveness: Can automatically perform a task as many
time as required
• Complexity: Performs complex calculation
• Speed: Works so fast
• Common data: One item can be used for different procedures.
37. Limitations of computer
• A computer cannot take any decision on its own.
• It functions as per a user’s instruction, so it is fully dependent
on human being
• It can’t do any adjustment as being can do.
• Can not Think
• Can not do anything Without Instructions
• Can not make any Judgment
