Management Information Systems, 4 th Edition 1 Chapter 4 Information Technology in Business: Hardware

Management Information Systems, 4th Edition 1

Chapter 4Information Technology in

Business: Hardware


Learning Objectives

• List major components of a computer and explain their functions

• Explain how computers communicate

• Classify computers into major categories, and identify their strengths and weaknesses

• Describe how computers have affected the development of business


Learning Objectives (Cont.)• Define the most commonly used hardware

terminology

• Identify and evaluate key criteria when deciding what computers or related devices to purchase

• Explain the controversy regarding the health hazards of computers

• Evaluate hardware so that you can harness it to improve managerial processes


The Central Tool of Modern Information Systems

• Computers are at the core of every modern information system

– Hardware: the physical components of the computer

– Software: the set of instructions that direct the hardware to perform particular tasks


Hardware components

• Input devices: receive signals from outside the computer and transfer them into the computer

– Computer keyboard and mouse

– Some input devices accept voice, image, or other signals


• Most important part of any computer

• Accepts instructions and data

• Decodes and executes instructions

• Stores results (output) in memory for later display

Central processing unit (CPU)


• Stores data and instructions just before and immediately after the CPU processes them

• Includes programs currently running on a machine

• Intermediate results of arithmetic operations

• Intermediate versions of documents being word processed

• Data that represent pictures displayed on a computer screen

• Sounds played by the speakers

Internal Memory or Main Memory


• Two types of memory

– RAM (random access memory)

– ROM (read-only memory)

• The amount of memory and the speed at which it can be retrieved are two properties that determine the power of a computer

Internal Memory or Main Memory (Cont.)


• Different types of media

– Magnetic disks, magnetic tapes, and optical discs

• Stores same types of data and information as internal memory does

• Allows for permanent storage and portability

External Memory


• Computer monitors and printers

• Deliver information from the computer to a person

• Audio output devices

• Specialized output devices: Braille writers

Output devices


• Devices for both output and input

– Printers that read memory cards to print digital images

• Most I/O devices are peripheral devices

• Most processing and storage devices are internal

• CPU and primary memory reside on the motherboard

The Central Tool of Modern Information Systems (Cont.)


The Central Tool of Modern Information Systems (Cont.)


How Computers Communicate: Bits And Bytes

• Computer recognizes two states:

– On or off

• Each on or off signal represents a bit (binary digit)


• Representation of symbols by unique strings of bits

• ASCII (American Standard Code for Information Interchange) originally with seven bits in a byte

• ASCII-8

– Newer version

– Consists of eight bits per byte

Encoding Schemes


Encoding Schemes (Cont.)


• EBCDIC, Developed by IBM with eight bits per byte

• Limitations in ASCII and EBCDIC to 256 different characters

• Unicode, 16 bits per byte, allows for many more characters

Encoding Schemes (Cont.)


• Counting Bases

– Decimal system is “base 10”

– Binary system is “base 2”

– Similar methods for calculations as humans

– Store all quantities and perform calculations in binary form

– Display numbers after translating to decimal presentation

Understanding Computer Processing


Classification of Computers• Supercomputers

– The largest, most powerful, and most expensive

– Used by universities, research institutions, and large corporations

• Mainframe Computers– Less powerful and less expensive than

supercomputers

– Used by businesses with large amounts of data that need to be stored in a central computer


Classification of Computers (Cont.)

• Midrange Computers

– Often used as the host computer in a network of smaller computers

– Priced in the several thousands to a few hundred thousand dollars

– Manufacturers: DEC (VAX), IBM (AS/400), and Hewlett-Packard



• Microcomputers

– Networks of microcomputers are replacing mainframes

– Sometimes called workstations

– Used for CAD, CAE, complex simulations and scientific applications


Classification of Computers (Cont.)• Microcomputers (cont.)

– The microprocessor chip

• Traditionally manufactured by Intel

• AMC and Cyrix are other manufacturers

• Macintosh are built around Motorola’s PowerPC chips

• Sun develops its own microprocessors and computers



• Computers on the Go: Notebook, Handheld, and Tablet computers– Computers used outside

the office

– 3x the desktop pc price

– Tablet pc is the newest option available



• Internet Appliances

– Handheld computers and other electronic devices manufactured with the capability to link to the Internet

– Can be wireless

– Considerations must be made for invasion of privacy concerns

– More devices being outfitted for Internet access all the time


Business Evolves with Computing

• Mainframe to PC: Networking Businesses

– With increased power of the PC, managers devise their own IS

– Businesses shifting from mainframe model to the client/server model

– One PC functions as the server

– Connects to other PCs, the clients


• Increasing power, decreasing cost

• Electronic computing began with early counting machines

• Electrical signals an important leap in technology

• 1942: first electronic computer at Iowa State

Trends in Computing


• Used by the US Government

• IBM machines used in ’50s and ’60s for business calculations, record keeping and more

• Today, nearly every new electronic device has a computer

Trends in Computing (Cont.)






A Peek Inside the Computer


A Peek Inside the Computer (Cont.)• The Central Processing Unit (CPU)

– The brain of the computer

– Has two components that store and process data:

• Control unit

• Arithmetic logic unit (ALU)

– Silicon chip with multiple circuits


A Peek Inside the Computer (Cont.)



• The Central Processing Unit (CPU) (cont.)

– Microprocessor

• Carries signals that execute all processing

• More transistors on the chip, the greater the power of the processor

• Silicon chip embedded with transistors, or semiconductors


Machine Cycle• CPU’s execution of four functions is one cycle:

– Fetch, Decode, Execute, Store

• Rate of repetitive cycles is Clock Rate

• One cycle per second is one hertz

– Computer frequencies are measured in megahertz (MHz─millions of hertz) or gigahertz (GHz─billions of hertz)

• System clock synchronizes all these tasks




• The Word: maximum number of bits fetched in one cycle

• The Arithmetic Logic Units Operations: where all arithmetic and logical operations take place

• Reduced Instruction Set Computing: fewer instructions resulting in faster computing




• Memory

– Registers

– Primary Memory

• Random access memory (RAM)

• Cache Memory

• Read-only memory (ROM)

– Volatile v. Nonvolatile


Computer Power

• Clock rate

• Bus: amount of information the CPU can process per second

• Throughput: speed determined only by combination of both factors


Input Devices • Keyboard

• Mouse, Trackball, and Track Pad

• Touch Screen

• Source Data Input Devices

• Imaging

• Speech Recognition


Input Devices (Cont.)


Output Devices

• Soft-Copy Output Devices

– Cathode-Ray Tube (CRT) Monitor

– Flat-Panel Monitor

– Speech Output

• Hardcopy Output Devices

– Nonimpact Printers (most common)

– Impact Printers


Output Devices (Cont.)


External Storage Media

• Important Properties to Consider

– Capacity, Access Speed, Access Mode, Cost

• Mode of Access

– Sequential v. Direct Access

• Magnetic tapes


External Storage Media (Cont.)

• Magnetic Disks

• Optical Disks

• Optical Tapes

• Flash Memory and Thumb Drives


Business Considerations of Storage Media

• Trade-offs

• Modes of Access

– Sequential Access: Tapes

– Direct Access: Disks






Considerations in Purchasing Hardware

• What should you consider when buying hardware?

– Power -- speed, size of memory, storage capacity

– Expansion and upgrade capability

– Ports for external devices like printers, hard disks, communication devices

– Ergonomics: Keyboard, Monitor


Considerations in Purchasing Hardware (Cont.)

• What should you consider when buying hardware (cont.)?

– Footprint

– Vendor reliability, warranty policy, vendor support

– Compatibility

– Cost


Factor What to Look For•Power Greater frequency and word size, larger

•Expandability Greater number of board slots for additional RAM

•Ports Greater number of ports for printer, external hard disk, communication devices and other peripherals

•Ergonomics Greater comfort and safety

•Compatibility Comparability with many other computers and peripheral devices, as swell as software packages

•Footprint Smaller area

•Support Availability of telephone and on-line support for troubleshooting

•Warranty Longer warranty period

•Cost Lower cost



Factor What to Look For•Power Greater frequency and word size, larger

•Expandability Greater number of board slots for additional RAM

•Ports Greater number of ports for printer, external hard disk, communication devices and other peripherals

•Ergonomics Greater comfort and safety

•Compatibility Comparability with many other computers and peripheral devices, as swell as software packages

•Footprint Smaller area

•Support Availability of telephone and on-line support for troubleshooting

•Warranty Longer warranty period

•Cost Lower cost



Ethical and Societal IssuesComputers May Be Hazardous to Your Health

• Physical and Emotional Stress

– General physical and emotional stress

– Muscular-skeletal problems

• Repetitive Stress Injuries (RSI)

– Vision problems


Summary• Computer components and their functions

• Computer communication

• Categories of computers have different strengths and weaknesses

• Understand commonly used hardware terminology

• Identify and evaluate key criteria for purchasing decisions

Documents

Management Information Systems, 4 th Edition 1 Chapter 4 Information Technology in Business: Hardware