Computer HardwareComputer Hardware

1313Orasa T.Orasa T.

• 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.

1313 Learning ObjectivesLearning Objectives

• Identify the components and functions of a computer system.

• Identify the computer system and peripherals you would acquire or recommend for a business of your choice.

1313 Learning Objectives (continued)Learning Objectives (continued)

• Computer Systems: End User and Enterprise Computing

1313 Section ISection I

• All computers are systems of input, processing, output, storage, and control components.

• Three basic categories– Mainframe– Midrange computers– Microcomputers

1313 Types of Computer SystemsTypes of Computer Systems

• Mainframe– Enterprise systems– Superservers– Transaction processors– Supercomputers

1313 Types of Computer Systems (continued)Types of Computer Systems (continued)

• Midrange– Network servers– Minicomputers– Web servers– Multi-user systems

1313 Types of Computer Systems (continued)Types of Computer Systems (continued)

• Microcomputers– Personal computers– Network computers– Technical workstations– PDAs– Information appliances

1313 Types of Computer Systems (continued)Types of Computer Systems (continued)

• The most important category of computers– Desktop– Laptop

• Workstation computers

• Network servers

1313 Microcomputer SystemsMicrocomputer Systems

• Selection criteria– Solid performance at a reasonable price

– Operating system ready

– Connectivity

1313 Microcomputer Systems (continued)Microcomputer Systems (continued)

• Network computers– Designed primarily for use with the

Internet and corporate intranets – For specialized or limited computing

applications– Lower cost of purchase, upgrades,

maintenance, and support

1313 Microcomputer Systems (continued)Microcomputer Systems (continued)

• Network computers (continued)– Other benefits

• Ease of software distribution and licensing• Computing platform standardization• Reduced end user requirements• Improved manageability

1313 Microcomputer Systems (continued)Microcomputer Systems (continued)

• Information appliances– PDAs

– Set-top boxes and video-game consoles

– Wireless PDAs

– Cellular and PCS phones

1313 Microcomputer Systems (continued)Microcomputer Systems (continued)

• Computer terminals– Dumb terminals

– Intelligent terminals

– Network terminals

– Transaction terminals

1313 Microcomputer Systems (continued)Microcomputer Systems (continued)

• Multi-user systems that can manage networks of PCs and terminals

• Less costly to buy, operate, and maintain than mainframes

• Popular as network servers

• Minicomputers

1313 Midrange Computer SystemsMidrange Computer Systems

• Large, fast, powerful

• Handle high transaction processing volumes or complex computational problems

• Super servers for large client/server networks and high-volume Internet websites

• Popular for data mining and warehousing

1313 Mainframe Computer SystemsMainframe Computer Systems

• Supercomputers– Extremely powerful systems

specifically designed for scientific, engineering, and business applications requiring extremely high speeds for massive numeric computations

– Use parallel processing architectures– Process at speeds measured in

gigaflops and teraflops

1313 Mainframe Computer Systems (continued)Mainframe Computer Systems (continued)

• Computers are organized according to the following system functions:– Input

• Keyboards• Touch screens• Pens• Electronic mice• Optical scanners• Convert data into electronic form

1313 The Computer System ConceptThe Computer System Concept

– Processing• Central Processing Unit (CPU)

– Two subunits» Arithmetic-Logic Unit (ALU)» Control Unit

1313 The Computer System Concept (continued)The Computer System Concept (continued)

– Output• Video display units• Printers• Audio response units

• Convert electronic information into human-intelligible form

1313 The Computer System Concept (continued)The Computer System Concept (continued)

– Storage• Store data and software instructions• May also include cache memory• Primary storage unit (hard drive)• Secondary storage

– Magnetic disks– Optical disk drives

1313 The Computer System Concept (continued)The Computer System Concept (continued)

– Control• The registers and other circuits of the

control unit interpret software instructions and transmit directions to the other components of the computer system

1313 The Computer System Concept (continued)The Computer System Concept (continued)

• Computer processing speeds– Milliseconds (thousandths of a second)– Microseconds (millionths of a second)– Nanoseconds (billionths of a second)– Picoseconds (trillionths of a second)

1313 The Computer System Concept (continued)The Computer System Concept (continued)

– Clock speeds• Megahertz (MHz)

– Millions of cycles per second

• Gigahertz (GHz)– Billions of cycles per second

1313 The Computer System Concept (continued)The Computer System Concept (continued)

• Computer Peripherals: Input, Output, and Storage Technologies

1313 Section IISection II

• Generic name given to all input, output, and secondary storage devices

• Depend on direct connections or telecommunications links to the CPU

• All peripherals are online devices

1313 PeripheralsPeripherals

• Natural user interface– Enter data and commands directly into

a computer• Electronic mice and touch pads• Optical scanning, handwriting recognition,

voice recognition

1313 Input TechnologiesInput Technologies

• Used for entering data and text

• Work with your operating system’s graphical user interface (GUI)– Electronic mouse– Trackball– Pointing stick– Touch pad– Touch screen

1313 Pointing DevicesPointing Devices

• Used in many hand-held computers and PDAs– Digitizer pen– Graphics tablet

1313 Pen-Based ComputingPen-Based Computing

• Digitize, analyze, and classify your speech and its sound patterns

• Allow operators to perform data entry without using their hands to key in data or instructions

• Speaker-independent

• Voice-messaging computers

1313 Speech Recognition SystemsSpeech Recognition Systems

• Read text or graphics and convert them into digital input

• Employ photoelectric devices to scan the characters being read

1313 Optical ScanningOptical Scanning

• Optical character recognition (OCR)– Reads OCR characters & codes

• Merchandise tags• Product labels• Sort mail, score tests

• Hand-held optical scanning wands– Reads bar coding– Universal Product Code (UPC)

1313 Optical Scanning (continued)Optical Scanning (continued)

• Magnetic stripe technology– Credit cards

• Smart cards– Embedded microprocessor chip

• Debit, credit, and other cards

• Digital cameras– Still cameras– Digital camcorders

1313 Other Input TechnologiesOther Input Technologies

• Magnetic ink character recognition (MICR) technology– Used by banks to sort and post checks

and deposit slips– 14 characters of a standardized design– Reader-sorters

• Video• Print• Storage

1313 Other Input Technologies (continued)Other Input Technologies (continued)

• Video monitors – Cathode ray tube (CRT)– Liquid crystal displays (LCDs)

1313 Video OutputVideo Output

• Inkjet– Spray ink onto the page one line at a

time

• Laser – Use an electrostatic process similar to

a copier

1313 Printed OutputPrinted Output

1313 Storage Trade-OffsStorage Trade-Offs

• Computer storage fundamentals– Information is stored through the

presence or absence of electronic or magnetic signals

• Binary representation– 1 = ON– 0 = OFF

1313 Storage Trade-Offs (continued)Storage Trade-Offs (continued)

• Computer storage fundamentals (continued)– Bit

• The smallest element of data• May have a value of either one or zero

– Byte• Basic grouping of bits• Typically, a byte consists of 8 bits and

represents one character of data

1313 Storage Trade-Offs (continued)Storage Trade-Offs (continued)

• Computer storage fundamentals (continued)– Storage capacities

• Kilobytes (KB)– 1,000 bytes

• Megabytes (MB)– 1 million bytes

1313 Storage Trade-Offs (continued)Storage Trade-Offs (continued)

• Computer storage fundamentals (continued)

• Gigabytes (GB)– 1 billion bytes

• Terabytes (TB)– 1 trillion bytes

• Petabyte (PB)– 1 quadrillion bytes

1313 Storage Trade-Offs (continued)Storage Trade-Offs (continued)

• Direct and sequential access– Terms direct access and random

access describe the same concept– An element of data or instructions can

be directly stored and retrieved by selecting and using any of the locations on the storage media

• Each storage position– Has a unique address– Can be individually accessed in approximately

the same time

1313 Storage Trade-Offs (continued)Storage Trade-Offs (continued)

• Direct and sequential access (continued)– Sequential access

• Does not have unique storage addresses• Serial process• Data are recorded one after another in a

predetermined sequence.• Locating an individual item requires

searching all of the data until the desired item is located

1313 Storage Trade-Offs (continued)Storage Trade-Offs (continued)

1313 Storage Trade-Offs (continued)Storage Trade-Offs (continued)

• Primary storage of your computer

• Advantages– Small size– Great speed– Shock and temperature resistant

• Disadvantage– Volatility

1313 Semiconductor MemorySemiconductor Memory

• Two basic types of semiconductor memory

– RAM – random access memory• Volatile memory• Read/write memory• “working” memory

1313 Semiconductor Memory (continued)Semiconductor Memory (continued)

– ROM – read only memory• Nonvolatile• Used for permanent storage• Can be read but not erased or overwritten

– Variations of ROM• PROM

– Programmable read only memory

• EPROM– Erasable programmable read only memory

1313 Semiconductor Memory (continued)Semiconductor Memory (continued)

• Most common form of secondary storage

• Data is recorded on tracks in the form of tiny magnetized spots

• Thousands of bytes recorded on each track

1313 Magnetic Disk StorageMagnetic Disk Storage

• Types of Magnetic Disks– Floppy disks

– Zip disks

– Hard disk drives

1313 Magnetic Disk Storage (continued)Magnetic Disk Storage (continued)

• Redundant arrays of independent disks (RAID)– Provides large capacities with high

access speeds– Data are accessed in parallel over

multiple paths from many disks– Fault tolerant– Storage area networks (SANs)

• Fiber channel LANs that connect many RAID units

1313 Magnetic Disk Storage (continued)Magnetic Disk Storage (continued)

• Used as secondary storage

• Also used in robotic automated drive assemblies

• Lower-cost storage

• Archival storage

1313 Magnetic Tape StorageMagnetic Tape Storage

• CD-ROM

• CD-R

• CD-RW

• DVD

• DVD-ROM

• DVD-RAM

1313 Optical Disk StorageOptical Disk Storage

• Business applications– Image processing– Provide access to reference materials

in a convenient, compact form– videos

1313 Optical Disk Storage (continued)Optical Disk Storage (continued)

• Do you agree with the statement: “The network is the computer”?

• What trends are occurring in the development and use of the major types of computer systems?

1313 Discussion QuestionsDiscussion Questions

• Do you think that network computers (NCs) will replace personal computers (PCs) in business applications?

• Are networks of PCs and servers making mainframe computers obsolete?

1313 Discussion Questions (continued)Discussion Questions (continued)

• What trends are occurring in the development and use of peripheral devices? Why are those trends occurring?

• When would you recommend the use of each of the following:– Network computers– NetPCs– Network terminals– Information appliances in business applications

1313 Discussion Questions (continued)Discussion Questions (continued)

• What processor, memory, magnetic disk storage, and video display capabilities would you require for a personal computer that you would use for business purposes?

• What other peripheral devices and capabilities would you want to have for your business PC?

1313 Discussion Questions (continued)Discussion Questions (continued)

• The Business Value of PDAs

• What are the business benefits of PDAs for business applications?

• What are the limitations of PDAs for business use?

1313Real World Case 1 – City of Richmond Real World Case 1 – City of Richmond & Tim Beaty Builders& Tim Beaty Builders

ReferencesReferences

• James A. O'Brien; George M. Marakas. Management Information Systems: Managing Information Technology in the Business Enterprise 6th Ed., Boston: McGraw-Hill/ Irwin,2004

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