Unit 1 provides an introduction to computers including their objectives, types (digital, analog, hybrid), evolution through generations, core components (CPU, memory, input/output devices), and number systems. Key points include: - Computers accept digital data as input, manipulate it according to programs, and provide results as output. - There are various types of computers including mini computers, supercomputers, mainframes, PCs, and workstations. - Computers have evolved through 5 generations from vacuum tubes to integrated circuits and microprocessors. - Core components include the CPU, memory, and input/output devices like keyboards, printers, and monitors.

1. Unit -I

2. In this Unit
• Introduction to Computer
• Objectives
• Types of Computer ( Digital/ Analog/Hybrid)
• Evolution and Generation of Computer
• Input /Output devices
• Central Processing unit
• Memory
• Devices
• Keyboard
• Printer – Types of printer – Monitor – Ports
• Number system

3. Computer

4. Introduction to computer
• A computer is a device that accepts information (in the form of
digitalized data) and manipulates it for some result based on a
program or sequence of instructions on how the data is to be
processed.. Complex computers also include the means for storing
data (including the program. which is also a form of data) for some
necessary duration. A program may be invariable and built into the
computer (and called logic circuitry as it is on microprocessors) or
different programs may be provided to the computer (loaded into its
storage and then started by an administrator or user). Today's
computers have both kinds of programming.
• With the advent of the Internet and higher bandwidth data
transmission, programs and data that are part of the same overall
project can be distributed over a network and embody the Sun
Microsystems (Oracle) slogan: "The network is the computer."

5. Objectives
• To provide students with the tools to identify problems that are
best solved by means of a computer and to design and implement
effective, efficient. and creative solutions.
• To provide students with a strong foundation in the software and
hardware aspects of computing, as well as the mathematics and
science of the discipline.
• To provide students with a deeper understanding of some specialty
within computer science.
• To provide students with good written and oral communication
skills.
• To provide students with an understanding and appreciation of the
societal consequences of technology, including computers. and of
the ethical issues that may arise with new technologies

6. Types of Computer
• Mini computer
• Super computer
• Mainframe computer

7. Mini Computer

8. • It is a midsize computer. In the past decade,
the distinction between large minicomputers
and small mainframes has blurred, however,
as has the distinction between small
minicomputers and workstations. But in
general. a minicomputer is a multiprocessing
system capable of supporting from up to 200
users simultaneously

9. Super computer and mainframe

10. • Supercomputer is a broad term for one of the fastest
computers currently available. Supercomputers are very
expensive and are employed for specialized applications
that require immense amounts of mathematical
calculations (number crunching). For example, weather
forecasting requires a supercomputer. Other uses of
supercomputers scientific simulations, (animated) graphics,
fluid dynamic calculations, nuclear energy research,
electronic design, and analysis of geological data (e.g. in
petrochemical prospecting). Perhaps the best known
supercomputer manufacturer is Cray Research.
• Mainframe was a term originally referring to the cabinet
containing the central processor unit or "main frame" of a
room-filling Stone Age batch machine. After the emergence
of smaller "minicomputer" designs in the early 1970s, the
traditional big iron machines were described as "mainframe
computers" and eventually just as mainframes. Nowadays a
Mainframe is a very large and expensive computer capable
of supporting hundreds, or even thousands, of users
simultaneously

11. Computer Definition
A computer is a machine that can be programmed to
manipulate symbols. Its principal characteristics are:
• It responds to a specific set of instructions in a well-defined
manner.
• It can execute a prerecorded list of instructions (a
program).
• It can quickly store and retrieve large amounts of data.
• Therefore computers can perform complex and repetitive
procedures quickly. precisely and reliably. Modern
computers are electronic and digital. The actual machinery
(wires, transistors, and circuits) is called hardware; the
instructions and data are called software

12. computers require the following hardware components:
• Central processing unit (CPU): The heart of the computer, this is the
component that actually executes instructions organized in programs
("software") which tell the computer what to do.
• Memory (fast, expensive, short-term memory): Enables a computer to
store, at least temporarily, data, programs, and intermediate results.
• Mass storage device (slower, cheaper, long-term memory): Allows a
computer to permanently retain large amounts of data and programs
between jobs. Common mass storage devices include disk drives and tape
drives.
• Input device: Usually a keyboard and mouse, the input device is the
conduit through which data and instructions enter a computer.
• Output device: A display screen, printer, or other device that lets you see
what the computer has accomplished.

13. • COMPUTER SIZES AND POWER
Computers can be generally classified by size and power as follows,
though there is considerable overlap:
• Personal computer: A small, single-user computer based on a
microprocessor.
• Workstation: A powerful, single-user computer. A workstation is
like a personal computer, but it has a more powerful
microprocessor and, in general, a higher-quality monitor.
• Minicomputer: A multi-user computer capable of supporting up to
hundreds of users simultaneously.
• Mainframe: A powerful multi-user computer capable of supporting
many hundreds or thousands of users simultaneously.
• Supercomputer: An extremely fast computer that can perform
hundreds of millions of instructions per second.

14. Personal Computer

15. Workstation
• Red hat Workstation

16. Mini computer

17. Main computer & Super computer

18. Workstation
• It is a type of computer used for engineering applications
(CAD/CAM), desktop publishing, software development, and other
types of applications that require a moderate amount of computing
power and relatively high quality graphics capabilities. Workstations
generally come with a large, high-resolution graphics screen, at
large amount of RAM, built-in network support, and a graphical
user interface. Most workstations also have a mass storage device
such as a disk drive, but a special type of workstation, called a
diskless workstation, comes without a disk drive. The most common
operating systems for workstations are UNIX and Windows NT. Like
personal computers, most workstations are single-user computers.
However, workstations are typically linked together to form a local-
area network, although they can also be used as stand-alone
systems.

19. THE EVOLUTION OF THE COMPUTER
• First Generation (1939-1954) - Vacuum tube
• Second Generation Computers (1954-1959) - Transistor
• Third Generation Computers (1959-1971) – IC(Integrated
Circuit)
• Fourth Generation (1971-1991) - Microprocessor
• Fifth Generation (1991 and Beyond)

20. First Generation (1939-1954) - Vacuum tube
20
• 1939 -1954 : Vacuum tube
• big size, release heat and consumed
high power
• Example :
(i) ENIAC
( Electronic Numerical Integrator And
Calculator )
(ii) UNIVAC I
( Universal Automatic Calculator )
Vacuum tubes (left). Mid 1940s. IBM pioneered the arrangement of
vacuum tubes in pluggable modules such as the one shown here on
the left. The IBM 650 was a first-generation computer.

21. Vacuum tube

22. Second Generation Computers (1954-1959) - transistor
22
• 1954 -1959 : Transistor & Diode
• Computer named Minicomputer :
IBM 7090 & IBM 7094.
• Release heat but the size is smaller & cheaper.
• FORTRAN & COBOL
•The era of miniaturization begins. Transistors are much
smaller than vacuum tubes, draw less power, and generate
less heat. Discrete transistors are soldered to circuit boards
like the one shown, with interconnections accomplished by
stencil-screened conductive patterns on the reverse side.
The IBM 7090 was a second-generation computer.

23. Transistor & Diode

24. Third Generation Computers (1959-1971) - IC
24
• 1959 - 1971 : IC ( Integrated Circuit )
• computer named microcomputer
Apple II, IBM PC, NEC PC & Sinclair
• small size, cheap & fast.
• BASIC, Pascal & PL/1 I
•Integrated circuits (foreground), silicon chips contain multiple transistors. 1964. A
pioneering example is the ACPX module used in the IBM 360/91. which, by stacking layers of
silicon over a ceramic substrate, accommodated over 20 transistors per chip; the chips could
be packed together onto a circuit board to achieve unheard-of logic densities. The IBM
360/91 was a hybrid second- and third-generation computer.

25. IC ( Integrated circuit )

26. Fourth Generation (1971-1991) - Microprocessor
26
•1971 - 1984 : VLSI ( Very Large Scale Integration )
• integrated with transistors in semiconductor
• Apple PC with Motorola Power PC603
• 1975,Bil Gates wrote the 1st Programming Language
(Basic) Compiler.
World 1st
microprocess
or

27. Fifth Generation (1991 and Beyond)
27
•1985 – today : microprocessor
• computer named supercomputer
x486, Pentium, Celeron, P4, Athlon, Core2 Duo, Phenom, Core2 Quad etc.
• affordable, very fast & reliable.
• OS : PC Dos, Macintosh, Linux, Windows Vista etc

28. • In the fifth generation, the VLSI technology
became ULSI (Ultra Large Scale Integration)
technology, resulting in the production of
microprocessor chips having ten million
electronic components. This generation is based
on parallel processing hardware and AI (Artificial
Intelligence) software. AI is an emerging branch
in computer science, which interprets means and
method of making computers think like human
beings. All the high-level languages like C and
C++, Java, .Net etc., are used in this generation.

29. Advantages of computer
• Computers can quickly process huge amount of data. Computers can
complete various tasks more effectively than most human-beings. It has
automated complex tasks that were once considered boring and tedious
for humans. Hence, Computer has greatly increased our efficiency to do
various tasks. The advantages of computer is given below:
• Stores data in digital format
• Huge storage
• Play games
• Calculations
• Prepare and store official documents
• Presentations
• Internet
• Multimedia
• Prepare books of accounts
• Reduced cost

30. Disadvantage of computer
• It is true that even computer is not free from defects. The
disadvantages of computer is given below
• Ever changing technology
• Increased manpower cost
• Computer stops responding
• Viruses
• Reduction in employment opportunity

31. Basic characteristics about computer are:
• Speed
• Accuracy
• Diligence
• Versatility
• Power of Remembering
• No IQ
• No Feeling
• Storage

32. Input Device
• Information and programs are entered into
the computer through Input devices
• The input device also retrieves information off
disks.

33. Input devices
• Keyboard
• Mouse
• Joy Stick
• Light pen
• Track Ball
• Scanner
• Graphic Tablet
• Microphone
• Magnetic Ink Card Reader(MICR)
• Optical Character Reader(OCR)
• Bar Code Reader
• Optical Mark Reader(OMR)

34. Output Device
• Output Devices displays information on the
screen (monitor) or the printer and sends
information to other computers. They also
display messages about what errors may have
occurred and brings up message or dialog box
asking for more information to be input. The
output device also saves information on the
disk for future use.

36. Central processing unit (CPU)
• The CPU or central processing unit is sometimes called the Control Unit
and directs the operation of the input and output devices. The
Coprocessor or the Arithmetic-Logic Unit does arithmetic and
comparisons. The memory or RAM temporarily stores information (files
and programs) while you are using or working on them. The BIOS or basic
input/output system controls the dialogue between the various devices.

37. Key board symbols and uses
• ENTER or RETURN - Moves the cursor down one line and to
the left margin. Enter also process commands such as
choosing an option in a dialog (message) boxes and
submitting a form

38. • DEL or DELETE - Deletes the character at cursor
and/or characters to the right of the cursor and all
highlighted (or selected) text.

39. • BKSP or BACKSPACE - Deletes the character to
the left of cursor and all highlighted text.

40. • SPACE BAR - Moves the cursor one space at a
time to the right

41. • SHIFT KEY - Use the shift keys to type capital letters and to type the upper character on
keys with two characters on them
• CAPS LOCK - Locks the keyboard so it types capital letters (a light goes on when caps lock
is on)
• 15
• Tab- Moves the cursor five spaces to the right (number of spaces are usually adjustable).
Tab moves to the next field in a form or table (Shift-Tab for previous field).
• ESC or ESCAPE - Cancels a menu or dialog box
• ARROW KEYS - Moves the cursor around document without changing text have special
keys used for a variety of different functions.

42. • FUNCTION KEYS or F KEYS - Access commands by themselves or in
combination with the three command keys; CTRL, SHIFT, and ALT
• Command or Special Keys
• Command keys normally do nothing on their own but work in
combination with other keys. Each piece of software uses the
command keys differently though there is a move to standardize
some functions. The Control key or Ctrl is often used to access
commands. The Alternative key or Alt is often used to access
menus. The Shift key is used to type CAPITAL LETTERS. As well the
• command keys are all used to move through documents and edit
text faster and easier. As well many computers have Special keys
design specifically for the particular computer. Apple computers
have the Apple keys and Macs have Command keys. Many
keyboards now have a Windows key specifically for Windows 9x and
newer systems. Many older computers also

43. Ports
A port:
• is a physical docking point using which an external device can be
connected to the computer.
• can also be programmatic docking point through which information
flows from a program to computer or over the internet.
• Characteristics
A port has the following characteristics:
• External devices are connected to a computer using cables and
ports.
• Ports are slots on the motherboard into which a cable of external
device is plugged in.
• Examples of external devices attached via ports are mouse,
keyboard, monitor, microphone, speakers etc.

45. Serial Port
• Used for external modems and older computer
mouse
• Two versions : 9 pin, 25 pin model
• Data travels at 115 kilobits per second
Parallel Port
• Used for scanners and printers
• Also called printer port
• 25 pin model
• Also known as IEEE 1284-compliant Centroids port

46. PS/2 Port
• Used for old computer keyboard and mouse
• Also called mouse port
• Most of the old computers provide two PS/2 port, each for
mouse and keyboard
• Also known as IEEE 1284-compliant Centroids port
Universal Serial Bus (or USB) Port
• It can connect all kinds of external USB devices such as
external hard disk, printer, scanner, mouse, keyboard etc.
• It was introduced in 1997.
• Most of the computers provide two USB ports as minimum.
• Data travels at 12 megabits per seconds
• USB compliant devices can get power from a USB port

47. VGA Port
• Connects monitor to a computer's video card.
• Has 15 holes.
• Similar to serial port connector but serial port connector has pins, it has
holes.
Power Connector
• Three-pronged plug
• Connects to the computer's power cable that plugs into a power bar or
wall socket
Fire wire Port
• Transfers large amount of data at very fast speed.
• Connects camcorders and video equipment's to the computer
• Data travels at 400 to 800 megabits per seconds
• Invented by Apple
• Three variants : 4-Pin FireWire 400 connector, 6-Pin FireWire 400
connector and 9-Pin FireWire 800 connector
Modem Port
• Connects a PC's modem to the telephone network

48. Ethernet Port
• Connects to a network and high speed Internet.
• Connect network cable to a computer.
• This port resides on an Ethernet Card.
• Data travels at 10 megabits to 1000 megabits per seconds
depending upon the network bandwidth.
Game Port
• Connect a joystick to a PC
• Now replaced by USB.
• Digital Video Interface, DVI port
• Connects Flat panel LCD monitor to the computer's high end video
graphic cards.
• Very popular among video card manufacturers.
Sockets
• Connect microphone, speakers to sound card of the computer

49. Printers
Printer is an output device, which is used to
print information on paper.
There are two types of printers:
• Impact Printers
• Non-Impact Printers

50. Impact Printers
The impact printers print the characters by striking them on the ribbon which is then
pressed on the paper.
Characteristics of Impact Printers are the following:
• Very low consumable costs
• Very noisy
• Useful for bulk printing due to low cost
• There is physical contact with the paper to produce an image
• These printers are of two types
Character printers
• Line printers
• Character Printers
• Character printers are the printers which print one character at a time.
These are further divided into two types:
• Dot Matrix Printer(DMP)
• Daisy Wheel

51. DOT MATRIX PRINTER
In the market one of the most popular printers is Dot Matrix
Printer. These printers are popular because of their ease of
printing and economical price. Each character printed is in form
of pattern of dots and head consists of a Matrix of Pins of size
(5*7, 7*9, 9*7 or 9*9) which come out to form a character that
is why it is called Dot Matrix Printer.
Advantages
• Inexpensive
• Widely Used
• Other language characters can be printed
Disadvantages
• Slow Speed
• Poor Quality

52. DAISY WHEEL
Head is lying on a wheel and pins corresponding to characters are like
petals of Daisy (flower name) that is why it is called Daisy Wheel
Printer. These printers are generally used for word-processing in offices
which require a few letters to be sent here and there with very nice
quality.
Advantages
• More reliable than DMP
• Better quality
• The fonts of character can be easily changed
Disadvantages
• Slower than DMP
• Noisy
• More expensive than DMP

53. Line Printers
Line printers are the printers which print one line at a time.
These are of further two types
• Drum Printer
• Chain Printer
DRUM PRINTER
This printer is like a drum in shape so it is called drum printer. The surface of drum is divided
into number of tracks. Total tracks are equal to size of paper i.e. for a paper width of 132
characters, drum will have 132 tracks. A character set is embossed on track. The different
character sets available in the market are 48 character set, 64 and 96 characters set. One
rotation of drum prints one line. Drum printers are fast in speed and can print 300 to 2000
lines per minute.
Advantages
• Very high speed
Disadvantages
• Very expensive
• Characters fonts cannot be changed
CHAIN PRINTER
In this printer, chain of character sets are used so it is called Chain Printer. A standard
character set may have 48, 64, or 96 characters.
Advantages
• Character fonts can easily be changed.
• Different languages can be used with the same printer.
Disadvantages
• Noisy

54. Non-impact Printers
• Non-impact printers print the characters without
using ribbon. These printers print a complete page
at a time so they are also called as Page Printers.
These printers are of two types
• Laser Printers
• Inkjet Printers
Characteristics of Non-impact Printers
• Faster than impact printers.
• They are not noisy.
• High quality.
• Support many fonts and different character size.

55. Laser Printers
These are non-impact page printers. They use laser lights to produce the dots
needed to form the characters to be printed on a page.
ADVANTAGES
• Very high speed
• Very high quality output
• Give good graphics quality
• Support many fonts and different character size
DISADVANTAGES
• Expensive.
• Cannot be used to produce multiple copies of a document in a single
printing.

56. Inkjet Printers
Inkjet printers are non-impact character printers based on a relatively new
technology. They print characters by spraying small drops of ink onto paper.
Inkjet printers produce high quality output with presentable features.
They make less noise because no hammering is done and these have many
styles of printing modes available. Color printing is also possible. Some
models of Inkjet printers can produce multiple copies of printing also.
ADVANTAGES
• High quality printing
• More reliable
DISADVANTAGES
• Expensive as cost per page is high
• Slow as compared to laser printer

57. Toner-based printers
Toner-based printers work using the Xerographic principle that is at
work in most photocopiers: by adhering toner to a light-sensitive print
drum, then using static electricity to transfer the toner to the printing
medium to which it is fused with heat and pressure.
Laser printers are available in both color and monochrome varieties.
Another toner based printer is the LED printer which uses an array of
LEDs instead of a laser to cause toner adhesion to the print drum
Liquid inkjet printers
Inkjet printers spray very small, precise amounts (usually a few
picolitres) of ink onto the media. These droplets of ink will carry a
slight electrical charge. The placement of the ink on the page is then
determined by the charge of a cathode and electrode between which
the ink moves towards the paper. Inkjet printing (and the related
bubble-jet technology) are the most common — quality inkjet printers
are inexpensive to produce.

58. Solid ink printers
Solid Ink printers, also known as phase-change printers, are a type of
thermal transfer printer. They use solid sticks of CMYK colored ink
(similar in consistency to candle wax), which are melted and fed into a
pies crystal operated print-head. The print head sprays the ink on a
rotating, oil coated drum. The paper then passes over the print drum,
at which time the image is transferred, or transfixed, to the page.
Dye-sublimation printers
A dye-sublimation printer (or dye-sub printer) is a printer which
employs a printing process that uses heat to transfer dye to a medium
such as a plastic card, paper or canvas. The process is usually to lay one
color at a time using a ribbon that has color panels. Dye-sub printers
are intended primarily for high-quality color applications, including
color photography; and are less well-suited for text. While once the
province of high-end print shops, dye-sublimation printers are now
increasingly used as dedicated consumer photo printers.

59. Inkless printers
Inkless printers use paper with colorless dye crystals embedded
between the two outer layers of the paper. When the printer is turned
on, heat from the drum causes the crystals to colorize at different rates
and become visible. One inkless printing technology, Zink, originally
developed at Polaroid, became available in 2007. Because of the way it
prints, the printer can be as small as a business card, the images are
waterproof, and in fact, one product slated for release by Zink Imaging
is a digital camera with a printer built into it.
Obsolete and special-purpose printing technologies
Thermal printers work by selectively heating regions of special heat-
sensitive paper. These printers are limited to special-purpose
applications such as cash registers and the printers in ATMs and
gasoline dispensers. They are also used in some older inexpensive fax
machines.

60. Other printers
• A number of other sorts of printers are important for historical reasons, or for
special purpose uses:
• Digital minilab (photographic paper)
• Electrolytic printers
• Microsphere (special paper)
• Spark printer (supplied for Sinclair ZX81)
• barcode printer multiple technologies, including: thermal printing, inkjet
printing, and laser printing barcodes
• Billboard / sign paint spray printers
• Laser etching (product packaging) industrial printers Printing mode
The data received by a printer may be:
• a string of characters
• a bitmapped image
• a vector image
Printing speed
The speed of early printers was measured in units of characters per second. More
modern printers are measured in pages per minute. These measures are used
primarily as a marketing tool, and are not well standardized. Usually pages per
minute refers to sparse monochrome office documents, rather than dense
pictures which usually print much more slowly. PPM are most of the time referring
to A4 paper in Europe and letter paper in the US, resulting in a 10% difference