Chapter 4 Information Technology in Business: Hardware

1. Chapter 4Information Technology in Business: Hardware April 19, 2003

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.

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.

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

5. Figure 4.1 All computers have the same basic components. The Central Tool of Modern Information Systems

6. Figure 4.2 Organizations have moved from using large mainframes to using networked PCs. The Central Tool of Modern Information Systems

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

8. Figure 4.6 A look inside a computer A Peek Inside the Computer

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

10. Figure 4.7 Schematic of how circuits on a chip would be open and closed to represent the letter D in EBCDIC (11000100) A Peek Inside the Computer • Microprocessor • Silicon chip embedded with transistors, or semiconductors

11. Figure 4.8 What happens inside the CPU in one machine cycle executing the operation 7 + 5 A Peek Inside the Computer

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

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

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

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

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

17. Keyboard QWERTY and Dvorak Ergonomic Mouse, Trackball, and Track Pad Touch Screen Speech Recognition Source Data Input Devices Source Data Technology Banking Credit Cards Shipping Imaging Input Devices

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

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

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

21. External Storage Media • Important Properties to Consider • Capacity • Speed • Mode • Cost

22. External Storage Media • Magnetic Tapes • Magnetic Disks • Optical Discs (Compact Discs) • Recording Technology • CD Drives • Optical Tape • Flash Memory

23. External Storage Media • Business Considerations of Storage Media • Trade-offs • Modes of Access • Sequential storage • Direct storage • Direct access storage devices

24. Figure 4.12 Characteristics of storage media for business consideration External Storage Media

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

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

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

28. Classification of Computers

29. Classification of Computers

30. Classification of Computers • Computers on the Go: Laptop, Hand-held, and Tablet Computers • Internet Appliances • Reduced Instruction Set Computing

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.

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

33. Considerations in the Purchase of Hardware • FactorWhat 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

34. 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

35. Ethical and Societal IssuesComputers 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

36. Ethical and Societal IssuesComputers 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