04Chapter Information Technology in Business- Hardware Effy Oz BZUPAGES

Management Information Systems, 3rd EditionEffy Oz

Chapter 4Information Technology in Business: Hardware


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Learning Objectives

• When you finish this chapter, you will:– Recognize major components of an electronic

computer.– Understand how the different components work.– Know the functions of peripheral equipment.

– Be able to classify computers into major categories, and identify their strengths and weaknesses.


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Learning Objectives

– Be able to identify and evaluate key criteria when deciding what computers to purchase.

– Know the controversy regarding the health hazards of computers.

– Recognize how to evaluate hardware so that you can harness it to improve managerial processes.


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The Central Tool of Modern Information Systems

• What Is a Computer?– A computer must handle four operations:

• Accept data

• Process data

• Store data and instructions

• Output data


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Figure 4.1 All computers have the same basic components.


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Figure 4.2 Organizations have moved from using large mainframes to using networked PCs.


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Computers Communicating: Bits And Bytes

• Computer recognizes two states: on or off– Each on or off signal represents a bit (binary digit)

• Encoding Schemes– Representation of symbols by unique strings of bits

• Understanding Computer Processing:– Counting Bases

• Decimal system is “base 10”• Binary system is “base 2”

– Used by computers


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A Peek Inside the Computer

Figure 4.6 A look inside a computer


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• The Central Processing Unit (CPU)– The brain of the computer– Two Components:

• Control unit

• Arithmetic logic unit (ALU)

– What is a Microprocessor?• Carries signals that execute all processing


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• Microprocessor– Silicon chip embedded with transistors,

or semiconductors

Figure 4.7 Schematic of how circuits on a chip would be open and closed to represent the letter D in EBCDIC (11000100)


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Figure 4.8 What happens inside the CPU in one machine cycle executing the operation 7 + 5


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• The Machine Cycle– CPU’s execution of four functions:

• Fetch

• Decode

• Execute

• Store

– Functions measured in small fractions of a second


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A Peek Inside the Computer• Memory

– Registers• CPU chip has designated areas for temporary storage of information

and rapid retrieval. – These storage areas are called registers.

– Internal Memory (used in actual processing of data inside the computer)

• Random access memory (RAM)

• Read-only memory (ROM)

– External Memory (not involved in processing)• Magnetic disks, magnetic tapes, optical discs


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• Memory– Random Access Memory

• All instructions and data are stored before CPU fetches for processing

– Cache Memory• Fast memory semiconductor chips (usually SRAM)• Stores most frequently used instructions of programs

the computer runs

– Read-Only Memory• Small part of internal memory• Maintains instructions and data the user need and

should not change


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• Memory: Volatile vs. non-volatile– Volatile (temporary)

• Depends on electrical current to maintain information

– Such as RAM and registers

– Non-volatile (permanent)• Programs and data stay in the chips when power is

off– Accessible again when computer is turned back on


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A Peek Inside the Computer• Computer Power

– Clock rate (measured in cycles per second)– Amount of information the CPU can process

per second– Speed determined only by combination of both

factors (speed of processing, word size, the maximum number of bits accessed by the CUP from internal memory, and the capacity of Buses used to facilitate internal communications between CPU and internal memory )


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Input Devices• Keyboard

– QWERTY and Dvorak– Ergonomic

• Mouse, Trackball, and Track Pad• Touch Screen• Source Data Input Devices

– Source Data Technology– Banking– Credit Cards– Shipping

• Imaging• Speech Recognition


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Input Devices

Figure 4.10 Banks use magnetic-ink character recognition (MICR) to automate their input procedures.


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Output Devices

• Soft-Copy Output Devices• Monitors

– Cathode-Ray Tube (CRT) Monitor– Flat-Panel Monitor

• Speech Output• Hardcopy Output Devices

– Nonimpact Printers (most common)– Impact Printers


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Output Devices

Figure 4.11 In an RGB monitor, the electron gun creates many different colors and hues from three primary colors: red, green, and blue.


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External Storage Media

• Magnetic Tapes • Magnetic Disks • Optical Discs (Compact Discs)

– Recording Technology

– CD Drives

• Optical Tape• Flash Memory


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• Business Considerations of Storage Media– Trade-offs– Modes of Access

• Sequential storage• Direct storage• Direct access storage devices


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• Important Properties to Consider– Capacity– Speed– Mode – Cost


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Figure 4.12 Characteristics of storage media for business consideration


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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


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• Minicomputers– Often used as the host computer in a network of

smaller computers– Priced in the tens of thousands to a few hundred

thousand dollars– Manufacturers: DEC (VAX), IBM (AS/400),

and Hewlett-Packard


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• The Microcomputer Revolution– Microcomputer: collective name for all

desktop computers• Also known as personal computers (PCs)

• More powerful micros are sometimes called workstations


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• Computers on the Go: Laptop, Hand-held, and Tablet Computers

• Internet Appliances

• Reduced Instruction Set Computing


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• Compatibility– Software and peripheral devices from one

computer can be used with another computer.– In a networked environment, computers need

to communicate to share databases and other computing resources.

– In addition to power and cost, compatibility is an extremely important factor in purchasing decisions.


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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– Vendor reliability, warranty policy, vendor

support


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Considerations in the Purchase of Hardware

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


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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


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• Electromagnetic Radiation– This small risk can be eliminated by using

Liquid Crystal Display monitor in lieu of cathode ray terminal monitors

• Flat monitors not only emit negligible amounts of electromagnetic radiation but are easier on the eyes

• Attempts to Legislate


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• Casting Doubt– Mayo Clinic 2001 study casts doubt that heavy

use of a PC is a main cause of carpal tunnel syndrome

• Editorial comment to study says results might have been influenced by sampled people and researchers being employed by the same company.

– lack of a control group

04Chapter Information Technology in Business- Hardware Effy Oz BZUPAGES

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