Management Information Systems, 3 rd Edition Effy Oz 2 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.

Management Information Systems, 3 rd Edition Effy Oz 3 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.

Management Information Systems, 3 rd Edition Effy Oz 4 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

Management Information Systems, 3 rd Edition Effy Oz 5 The Central Tool of Modern Information Systems Figure 4.1 All computers have the same basic components.

Management Information Systems, 3 rd Edition Effy Oz 6 The Central Tool of Modern Information Systems Figure 4.2 Organizations have moved from using large mainframes to using networked PCs.

Management Information Systems, 3 rd Edition Effy Oz 7 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

Management Information Systems, 3 rd Edition Effy Oz 8 A Peek Inside the Computer Figure 4.6 A look inside a computer

Management Information Systems, 3 rd Edition Effy Oz 9 A Peek Inside the Computer 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

Management Information Systems, 3 rd Edition Effy Oz 10 A Peek Inside the Computer 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 ( )

Management Information Systems, 3 rd Edition Effy Oz 11 A Peek Inside the Computer Figure 4.8 What happens inside the CPU in one machine cycle executing the operation 7 + 5

Management Information Systems, 3 rd Edition Effy Oz 12 A Peek Inside the Computer The Machine Cycle –CPU’s execution of four functions: Fetch Decode Execute Store –Functions measured in small fractions of a second

Management Information Systems, 3 rd Edition Effy Oz 13 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

Management Information Systems, 3 rd Edition Effy Oz 14 A Peek Inside the Computer 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

Management Information Systems, 3 rd Edition Effy Oz 15 A Peek Inside the Computer 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

Management Information Systems, 3 rd Edition Effy Oz 16 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 )

Management Information Systems, 3 rd Edition Effy Oz 17 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

Management Information Systems, 3 rd Edition Effy Oz 18 Input Devices Figure 4.10 Banks use magnetic-ink character recognition (MICR) to automate their input procedures.

Management Information Systems, 3 rd Edition Effy Oz 19 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

Management Information Systems, 3 rd Edition Effy Oz 20 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.

Management Information Systems, 3 rd Edition Effy Oz 21 External Storage Media Magnetic Tapes Magnetic Disks Optical Discs (Compact Discs) –Recording Technology –CD Drives Optical Tape Flash Memory

Management Information Systems, 3 rd Edition Effy Oz 22 External Storage Media Business Considerations of Storage Media –Trade-offs –Modes of Access Sequential storage Direct storage Direct access storage devices

Management Information Systems, 3 rd Edition Effy Oz 23 External Storage Media Important Properties to Consider –Capacity –Speed –Mode –Cost

Management Information Systems, 3 rd Edition Effy Oz 24 External Storage Media Figure 4.12 Characteristics of storage media for business consideration

Management Information Systems, 3 rd Edition Effy Oz 25 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

Management Information Systems, 3 rd Edition Effy Oz 26 Classification of Computers 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

Management Information Systems, 3 rd Edition Effy Oz 27 Classification of Computers The Microcomputer Revolution –Microcomputer: collective name for all desktop computers Also known as personal computers (PCs) More powerful micros are sometimes called workstations

Management Information Systems, 3 rd Edition Effy Oz 28 Classification of Computers

Management Information Systems, 3 rd Edition Effy Oz 29 Classification of Computers

Management Information Systems, 3 rd Edition Effy Oz 30 Classification of Computers Computers on the Go: Laptop, Hand-held, and Tablet Computers Internet Appliances Reduced Instruction Set Computing

Management Information Systems, 3 rd Edition Effy Oz 31 Classification of Computers 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.

Management Information Systems, 3 rd Edition Effy Oz 32 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

Management Information Systems, 3 rd Edition Effy Oz 33 Considerations in the Purchase of Hardware Factor What to Look For PowerGreater frequency and word size, larger ExpandabilityGreater number of board slots for additional RAM PortsGreater number of ports for printer, external hard disk, communication devices and other peripherals ErgonomicsGreater comfort and safety CompatibilityComparability with many other computers and peripheral devices, as swell as software packages FootprintSmaller area SupportAvailability of telephone and on-line support for troubleshooting WarrantyLonger warranty period Cost Lower cost

Management Information Systems, 3 rd Edition Effy Oz 34 Ethical and Societal Issues Computers May Be Hazardous to Your Health Physical and Emotional Stress –General physical and emotional stress –Muscular-skeletal problems Repetitive Stress Injuries (RSI) –Vision problems

Management Information Systems, 3 rd Edition Effy Oz 35 Ethical and Societal Issues Computers May Be Hazardous to Your Health 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

Management Information Systems, 3 rd Edition Effy Oz 36 Ethical and Societal Issues Computers May Be Hazardous to Your Health 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