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

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. 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. 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. Pre-Computer Calculations

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

7. Early Computing 19th Century 1880s
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. 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. ENIAC

10. Electronic Computers 1950s ENIAC replaced by UNIVAC 1, then IBM 704
Calculations jumped to 100,000 per second

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

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

13. Microcomputers 1975 1977 ALTAIR, programmed by flicking switches
Commodore & Radio Shack produce PCs

14. Microcomputers 1979 1982 Apple computer, the fastest selling PC.
IBM introduced the PC, which changed the market

15. Categories of Computer Systems

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

17. Microcomputer Systems

18. Microcomputer Systems
Apollo 11 spacecraft
Today's computers
Apollo 11 spacecraft
4 GHz
2.048 MHz CPU
1 Pound
70 Pounds

19. Recommended PC Features

20. Microcomputer Uses Workstations Network Servers
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

21. Workstations
Genetic image analysis workstation
Example CAD

22. Microcomputer Uses Terminals Types
Any device that allows access to a computer
Types
Dumb
Network (Windows or Internet)
Intelligent
Transaction
Dumb terminals: limited \ no processing capabilities. Example: Keyboard\ monitor.
Intelligent terminals: A computer input/output device with its own memory and logic circuits which can perform certain operations normally carried out by the computer. Also known as smart terminal.
Transaction terminals: ex debit card” magnetic strep reader” barcode reader ATM

23. Terminals

24. Network Computers Corporate PC Criteria:
Solid performance at a reasonable price
Operating system ready, from the network servers
No or minimal disk storage linked to network
Connectivity
Security-equipped
Low TCO
Ease of software distribution and licensing

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

26. Information Appliances

27. 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
First became popular as minicomputers
E.g. used in manufacturing plants.
Used as front-end servers
Assists mainframes with telecommunications and networks

28. 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
Widely used as superservers for…
Large client/server networks
High-volume Internet websites for large companies
Becoming a popular computing platform for…
Data mining, warehousing, electronic commerce applications

29. Mainframes

30. Super-server

31. Supercomputer Systems
Extremely powerful systems designed for…
Scientific, engineering, and business applications
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. Minisupercomputers Use (SMP) symmetric multiprocessing
(DSM) distributed shared memory, smaller number of interconnected microprocessors
Price range: hundreds of thousands

33. 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

34. Distributed (grid) Computing
Advantage: computers can be purchased as a hardware and when combined, produces similar computer resources to a multiprocessor supercomputer
Significantly cheaper
Can be formed from computing resources belonging to multiple individuals or organizations e.g. SETI

35. Grid Computing

36. Distributed (grid) Computing
Disadvantage: Computers might not be trustworthy
Solution: Assign same work to different nodes
Disadvantage: Lack of central control over the hardware, computers might drop out of the network.
Solution: Assign work and reduce the need for continuous connectivity. Reassign work when no result is reported.

37. Computer System Concept
Input
Control
System of hardware devices organized by function
Processing
Storage
Output

38. Computer System Concept

39. Computer Processing Speeds
Early computers
Milliseconds (thousandths of a second)
Microseconds (millionths of a second)
Current computers
Nanoseconds (billionth of a second)
E.g. person
Picoseconds (trillionth of a second)
Program instruction processing speeds
Million instructions per second (MIPS)
Megahertz (millions of cycles per second)
Gigahertz (billions of cycles per second)
Commonly called “clock speed”

40. Computer Processing Speeds
Throughput
Ability to perform useful computation or data processing assignments during a given period
Speed is dependant on…
Size of circuitry paths (buses) that interconnect microprocessor components
Capacity of instruction processing registers
Use of high-speed cache memory
Use of specialized microprocessors, such as math coprocessor

41. Moore’s Law
Originally observed in 1965, Moore’s Law holds true today
Common corollary of Moore’s Law…
Computing prices will be cut in half every 18 to 24 months
This has been consistently accurate
Applies to cost of storage as well
Doubling of the number of transistors per integrated circuit every 18 to 24 months

42. Moore’s Law
Can computers get any faster? Can we afford the computers of the future?
The price of a given level of computing power will be cut in half approximately every 18 to 24 months
It is useful in understanding where we have been and where are we going
This caused marketing and engineering departments of semiconductor manufacturers to focus on the increase in processing power.
The improvement in hardware does not mean improvement in the software.

43. Computer Peripherals: Input, output, and storage technology

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

45. Peripherals Advice

46. Input Technologies Common input devices Keyboard
Graphical User Interface (GUI)
Electronic mouse and trackball
Pointing stick
Touchpad
Touch screen

47. Input technologies Keyboard: most widely-used
Graphical user interface (GUI)
Icons, menus, windows, buttons, bars
Used for selection
Trend to natural user interface as opposed to paper source documents

48. 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.

49. 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.

50. 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

51. 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

52. 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

53. 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

54. Optical Scanning Scanners Optical Character Recognition (OCR)
Compact desktop models are popular for low cost and ease of use
Larger, more expensive flatbed scanners are faster, offer high-resolution color scanning
Optical Character Recognition (OCR)
Software that reads characters and codes
Used to read merchandise tags, sort mail, score tests, read bar codes

55. Other Input Technologies
Magnetic Stripe
Smart Cards
Digital Cameras
Magnetic Stripe
Reads the magnetic stripe on credit cards
Smart Cards
Microprocessor chip and memory on credit card
Used more in Europe than in the U.S.
Digital Cameras
Allows you to shoot, store, and download photos or full-motion video with audio into a PC
Images and audio can then be edited or enhanced
Magnetic Ink Character Recognition (MICR)
Identification numbers of bank and account printed in magnetic ink on bottom of check
Used by banks to magnetically read checks and deposit slips
Requires an iron oxide-based ink
Reader-sorter equipment magnetizes the ink, then passes it under a reading head to sense the signal
Magnetic Ink Character Recognition (MICR)

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

58. Storage Tradeoffs Storage media cost, speed, and capacity tradeoffs.
Cost increases with faster access speeds but decreases with increased capacity.

59. Computer Storage Fundamentals
Uses two-state (binary) data representation
On (1) or Off (0)
Data processed & stored in computer systems through On/Off signals
Bit
Smallest element of data
Either zero or one
Binary representation
Data are processed and stored in computer system through the presence or absence of signals
Either ON or OFF
ON = number 1
OFF = number 0
Bit (short for binary digit)
Smallest element of data
Either zero or one
the capacity of memory chips is represented in bits
Byte
Group of eight bits which operate as a single unit
Represents one character or number
Group of eight bits, which operate as a single unit
Byte
Represents one character or number

60. Representing Characters in Bytes

61. 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

62. Direct (Random) and Sequential Access

63. 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.

64. 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.

65. 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

66. 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

67. 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

68. Hard Disk Drives & Floppy Disks (diskettes)
Magnetic Disks
Hard Disk Drives & Floppy Disks (diskettes)
Floppy Disks (diskettes)
Magnetic disk inside a plastic jacket
Hard Disk Drives (hard drives)
Magnetic disk, access arms, and read/write heads in sealed module for stable environment
The design allow for higher speed, greater data recording, more tolerance.
Fixed or removable
Capacity from several hundred MBs to hundreds of GBs
Used for secondary storage
Fast access and high capacity
Reasonable cost

69. 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

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

71. Optical Disks

72. Uses of Optical Disks Long-term storage of historical image files
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

73. 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

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