This document provides an overview of the history and evolution of computer hardware from early mechanical calculators to modern electronic computers. It describes the major types of computer systems including microcomputers, midrange systems, mainframes, and supercomputers. It also outlines various input, output, and storage technologies such as keyboards, mice, displays, memory chips, magnetic disks, tapes, and optical disks. The document is intended to help readers understand computer hardware components and select appropriate systems and peripherals for different business needs.

1. Computer Hardware
Chapter 3
Copyright © 2010 by the McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill/Irwin

2. 3-2
Learning Objectives
Understand the history and evolution of
computer hardware
Identify the major types and uses of
microcomputer, midrange, and mainframe
computer systems
Outline the major technologies and uses of
computer peripherals for input, output, and
storage

3. 3-3
Learning Objectives
Identify and give examples of the components
and functions of a computer system
Identify the computer systems and peripherals
you would acquire or recommend for a
business of your choice, and explain the
reasons for your selection

4. 3-4
Pre-Computer Calculations
 Counting on fingers and toes
 Stone or bead abacus
– Calculate comes from calculus,
the Latin word for small stone
 1642: first mechanical adding machine
– Invented by Blasé Pascal, wheels moved counters
– Modified in 1674 by Von Leibnitz

5. 3-5
Pre-Computer Calculations

6. 3-6
Pre-Computer Calculations
 Age of industrialization
– Mechanical loom used punch cards
 Above left: Punch card reader. Above right: Punch card writer

7. 3-7
Early Computing
19th Century
– Charles Babbage proposed the Analytical
Engine, which could calculate, store values
in memory, perform logical comparisons
– Never built due to of lack of electronics
1880s
– Hollerith’s punched cards used to record
census data using On/Off patterns –
representing digits and letters.
– The holes turned sensors On or Off when
run through tabulating machine
– This company became the foundation for IBM

8. 3-8
Electronic Computers
1946 - First Generation Computer
– ENIAC (Electronic Numerical Integrator and Computer )
– Programmable
– 5000 calculations per second
– Used vacuum tubes
– Drawbacks were size and processing ability
(140 square meters)

9. 3-9

10. 3-10
ENIAC

11. 3-11
Electronic Computers
1950s
– ENIAC replaced by UNIVAC 1, then IBM 704
– Calculations jumped to 100,000 per second

12. 3-12
Waves of Computing
Late 1950s - Second Generation
– Transistors replaced vacuum tubes
– 200,000 to 250,000 calculations per second

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Waves of Computing
Mid-1960s - Third Generation
– Integrated circuitry and miniaturization
1971 - Fourth Generation
– Further miniaturization, multiprogramming,
virtual storage
1980s - Fifth Generation
– Millions of calculations per second

14. 3-14
Microcomputers
1975
– ALTAIR, programmed by flicking switches
1977
– Commodore & Radio Shack produce PCs

15. 3-15
Microcomputers
1979
– Apple computer, the fastest selling PC.
1982
– IBM introduced the PC, which changed the
market

16. 3-16
Categories of Computer Systems

17. 3-17
Microcomputer Systems
Computing power now exceeds that of the
mainframes of previous generations
Called a personal computer or PC
Relatively inexpensive
Hand-held, notebook, laptop, tablet,
portable, desktop, and floor-standing
Networked professional workstations used by businesses

18. 3-18
Microcomputer Systems

19. 3-19
Microcomputer Systems
Apollo 11 spacecraft
Apollo 11 spacecraft Today's computers
2.048 MHz CPU 4 GHz
70 Pounds 1 Pound

20. 3-20
Recommended PC Features

21. 3-21
Microcomputer Uses
Workstations
Supports heavy
mathematical
computer and
graphics display
demands
CAD, investment,
and portfolio analysis
Network Servers
More powerful than
workstations
Coordinates
telecommunications
and resource sharing
Supports small
networks (LAN)and
Internet or intranet
websites

22. 3-22
Workstations

23. 3-23
Microcomputer Uses
Terminals
– Any device that allows
access to a computer
Types
– Network
(Windows or Internet)
– Intelligent
e.g. Transaction

24. 3-24
Terminals

25. 3-25
Network Computers
 Microcomputer designed for use with internet and
intranets with limited computing applications.
 Operating system, applications and storage ready ,
from the network servers
 Low TCO
 Ease of software distribution and licensing
 Computing platform standardization

26. 3-26
Information Appliances
 Hand-held microcomputer devices also Known as
personal digital assistants (PDAs)
– Web-enabled PDAs use touch screens,
handwriting recognition, or keypads so that mobile
workers use to access email or the Web, exchange
data(appointments, to do list) with desktop PCs or
servers
– Latest entrant is the BlackBerry, iPhone
 PDAs include
– Video-games

27. 3-27
Information Appliances

28. 3-28
Midrange Systems
 High-end network servers that handle large-scale
processing of business applications
– Not as powerful as mainframes
– Less expensive to buy, operate, maintain
 Often as a powerful network server used to manage
– Large Internet websites, intranets, extranets
– Integrated, enterprise-wide applications

29. 3-29
Mainframe Computer Systems
 Large, fast, powerful computer systems
– Large primary storage capacity
– Reduction in acquisition and operating cost (coolers)
– High transaction processing
– Handles complex computations
– E.g. international banks, oil companies

30. 3-30
Mainframes

31. 3-31
Supercomputer Systems
 Extremely powerful systems designed for…
– Scientific, engineering, and business applications that
requires massive numeric computations
 Markets include…
– Government research agencies
– Large universities
– Major corporations
– E.g. global weather forecasting
 Uses parallel processing or (MPP)
– Billions to trillions of operations per second
(gigaflops and teraflops)
– Price range

32. 3-32
The Next Wave of Computing
Harnessing the infinite amount of unused
computing power
Desktops and laptops within an organization
Distributed or grid computing (opposite to traditional
supercomputers)
Parallel computing that relies on complete computers
connected to a network
Harnesses the unused CPU power in all connected
computers, even between organizations

33. 3-33
Grid Computing

34. 3-34
Computer System Concept
System of
hardware devices
organized by
function
Input
Processing
Output
Storage
Control

35. 3-35
Computer System Concept

36. 3-36
Moore’s Law
Doubling of the number of transistors
per integrated circuit every 18 to 24 months

37. 3-37
Computer Peripherals:
Input, output, and storage
technology

38. 3-38
Peripherals
Separate from, and not under the
control of, the CPU
Offline Devices
Separate from the CPU, but
electronically connected to (and
controlled by) it
Online Devices
Generic name for all input, output,
and secondary storage devices
Peripheral
Parts of the computer system (not
the CPU)
All online devices

39. 3-39
Peripherals Advice

40. 3-40
Input Technologies
 Common input devices
– Keyboard
– Graphical User Interface
(GUI)
– Electronic mouse
and trackball
– Pointing stick
– Touchpad
– Touch screen

41. 3-413-41
Input technologies
Keyboard: most widely-used
Graphical user interface (GUI)
– Icons, menus, windows, buttons, bars
– Used for selection

42. 3-423-42
Pointing Devices
Electronic Mouse
Trackball – Stationary device like a mouse
– Roller ball used to move cursor on screen.
Pointing Stick – Small eraser head-like device
in keypad
– Moves cursor in direction of pressure placed
on stick.

43. 3-433-43
Pointing Devices
Touchpad – Small rectangular touch-sensitive
surface
– Moves the cursor in the direction of finger
moves on the pad
Touch Screen – use computer by touching
screen
– Video display screen that emits a grid of
infrared beams, sound waves, or a slight
electric current
– Grid is broken when the screen is touched.

44. 3-44
Pen-Based Computing
 Used in Tablet PCs and PDAs
– Pressure-sensitive layer, similar to touch screen,
under liquid crystal display screen
– Software digitizes handwriting, hand printing, and
hand drawing

45. 3-45
Speech Recognition Systems
Speech may be the future of data entry
– Easiest, most natural means of human
communication
Recognizing speech patterns
– Discrete, requires pauses between each word
– Continuous speech recognition software (CSR)
recognizes continuous, conversationally paced
speech

46. 3-46
Speech Recognition Software
Speech recognition systems digitize, analyze,
and classify speech and sound patterns
– Compares to a database of sound patterns
– Passes recognized words to software
– Typically requires voice recognition training
Speaker-independent systems
– Allow computers to recognize words from a
voice never heard before
– Typically used in voice-messaging computers

47. 3-47
Optical Scanning
 Devices read text or graphics and convert them into
digital computer input
– Enables direct entry of data from source documents
 Document management library system
– Scans documents, then organizes and stores them
for easy reference or retrieval

48. 3-48
Optical Scanning
Optical Character Recognition (OCR)
Software that reads
characters and codes
Used to read merchandise
tags, sort mail, score tests,
read bar codes

49. 3-49
Other Input Technologies
Magnetic Stripe
Magnetic Ink Character
Recognition (MICR)
Digital Cameras
Smart Cards

50. 3-50

51. 3-51
Output Technologies
Voice Response Increasingly found along with
video displays in business
applications
Video Displays Cathode-ray tube (CRT)
Printed Output Inkjet and laser
Liquid crystal display (LCD)
Plasma displays
(TVs, flat-panel monitors)

52. 3-52
Storage Tradeoffs

53. 3-53
Computer Storage Fundamentals
On (1) or Off (0)
Data processed & stored in computer
systems through On/Off signals
Uses two-state
(binary) data
representation
Uses two-state
(binary) data
representation
Smallest element of data
Either zero or one
BitBit
Group of eight bits, which operate
as a single unit
Represents one character or number
ByteByte

54. 3-54
Representing Characters in Bytes

55. 3-55
Storage Capacity Measurement
Kilobyte (KB) One thousand bytes
Megabyte (MB) One million bytes
Gigabyte (GB) One billion bytes
Terabyte (TB) One trillion bytes
Petabyte (PB) One quadrillion bytes

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Direct (Random) and Sequential Access

57. 3-57
Direct Access
Direct or Random Access
– Also called random access.
– Directly store and retrieve data
– Each storage position has:
 a unique address
 can be accessed in the same length of time
– Represent primary storage devices such as:
Semiconductor memory chips, magnetic disks.

58. 3-58
Sequential Access
Sequential Access
– Data is stored and retrieved sequentially
– Must be accessed in sequence by searching
through prior data
– Media such as: Magnetic tape known as
sequential access devices.

59. 3-59
Semiconductor Memory
Microelectronic semiconductor memory chips
are used for primary storage
– Advantages: small size, fast, shock and
temperature resistance
– Disadvantages: volatility; must have
uninterrupted electric power or loses memory

60. 3-60
Types of Semiconductor Memory
Random Access
Memory (RAM)
Read-Only Memory
(ROM)
1. Most widely used
primary storage
medium
2. Volatile memory
3. Read/write memory
1. Permanent storage
“nonvolatile”
2. Can be read, but not
overwritten
3. Frequently used
programs burnt into
chips during
manufacturing
4. Called firmware

61. 3-61
Flash Drives
Sometimes called a jump drive
– Uses a small chip containing
thousands of transistors
– Can store data for virtually
unlimited periods without power
– Easily transported
– Highly durable
– Storage capacity of up to 20 GB
– Plugs into any USB port

62. 3-62
Magnetic Disks
Used for secondary storage
– Fast access and high capacity
– Reasonable cost
Hard Disk Drives & Floppy Disks (diskettes)

63. 3-63
RAID Storage
Redundant Arrays of Independent Disks
– Provides virtually unlimited online storage
– 6 to more than 100 hard disk drives are
combined into a single unit
– Data is accessed in parallel, over multiple
paths, from many disks
– Redundant storage of data on several disks
provides fault-tolerant capacity
Storage area networks can interconnect
many RAID units

64. 3-64
Magnetic Tape
Secondary storage
– Tape reels, cassettes, and cartridges
– Used in robotic, automated drive assemblies
– Archival and backup storage
– Lower-cost storage solution

65. 3-65
Optical Disks

66. 3-66
Uses of Optical Disks
Image Processing
Long-term storage of
historical image files
Storage of scanned documents
Publishing Medium
Allows fast access to
reference materials
Catalogs, directories, and so on
Interactive
Multimedia
Applications
Video games, educational videos, and
so on

67. 3-67
Radio Frequency Identification (RFID)
 One of the newest, fastest growing storage
technologies
– System for tagging and identifying mobile objects
– Used with store merchandise, postal packages,
casino chips, pets
– Special reader allows objects to be tracked as
they move from place to place
– Chips half the size of a grain of sand
 Passive chips derive power from reader signal
 Active chips are self-powered

68. 3-68
RFID Versus Bar Coding
Invisible nature of the system
Capacity to transmit fairly sophisticated
messages
Privacy
Concerns
Privacy
Concerns
Scans from greater distance
Can store dataRFIDRFID