Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc. 3-1 Introduction to Information Technology 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc. Chapter 3: Computer Hardware Prepared by: Roberta M. Roth, Ph.D. University of Northern Iowa

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc. 3-2 Chapter Preview  In this chapter, we will study:  The hardware components of an information system: CPU (central processing unit) Memory (primary and secondary storage) Input devices Output devices.  The classification of computers by power.  Strategic issues regarding hardware.

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc. 3-3 The Central Processing Unit (CPU) Input Devices Secondary Storage Output Devices Control Unit Primary Storage ALU Registers The CPU Communication Devices

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc. 3-4 The CPU (continued)  A microprocessor that executes instructions to perform processing tasks. Component parts are:  Control Unit  Arithmetic-Logic Unit  Registers  Primary Storage Control Unit Primary Storage ALU Registers The CPU

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc. 3-5 The CPU (continued)  Control Unit  Access program instructions  Decode (interpret) instructions  Control flow of data throughout system  Data flows through paths called buses Control Unit Primary Storage ALU Registers The CPU

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc. 3-6 The CPU (continued)  Arithmetic-Logic Unit  Perform computations on data  Perform comparisons on data Control Unit Primary Storage ALU Registers The CPU

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc. 3-7 The CPU (continued)  Registers  High speed storage areas  Hold data and instructions Control Unit Primary Storage ALU Registers The CPU

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc. 3-8 The CPU (continued)  Primary Storage (Main Memory)  Stores instructions from programs  Stores data to be processed Control Unit Primary Storage ALU Registers The CPU

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc. 3-9 The CPU (continued)  Machine Instruction Cycle  An instruction is fetched from primary storage by the Control Unit  The Control Unit decodes the instruction  The ALU receives the data and the instruction and performs the calculation or comparison  The result is stored in primary storage.

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc The CPU (continued)  Computer performance is measured in part by the number of Machine Instruction Cycles performed per second.  Factors affecting this performance include:  Clock Speed  Word Length  Bus Width  Line Width

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc The CPU (continued)  Microprocessors evolved rapidly due to  Miniaturation of transistors  Decreasing distance between transistors on the chip (decreasing line width)  Improved conductivity (flow) of electricity  Improved instruction sets programmed into the chip.  Smaller, faster, cheaper, more powerful chips with each generation.

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc Computer Memory Input Devices Secondary Storage Output Devices Control Unit Primary Storage ALU Registers The CPU Communication Devices

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc Computer Memory Basics  Computers are digital, and represent data in bit patterns  Bit is shorthand for Binary digIT. The binary system consists of two values: 0 & 1  8 bits = byte  Bytes are the basic measure of storage in computers  ASCII Code assigns a unique character to each pattern of 0s &1s in a byte.  Kilobytes, Megabytes, Gigabytes, Terabytes

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc Primary Storage (Main Memory)  Main memory is a temporary storage area that holds three things…  information you are working with  the application software you are using  the operating system software  Increasing memory capacity increases the performance of the system

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc Primary Storage (Main Memory)  Types of Primary Storage  Registers – part of the CPU; very fast; very limited capacity  Random Access Memory (RAM) – memory chips on motherboard; general storage of program instructions and data; volatile  Cache Memory – faster than RAM; used to provide intermediate storage between secondary storage and RAM  Read-only Memory (ROM) – chips storing permanent instructions needed by computer; non-volatile

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc Secondary Storage  Non-volatile storage of data and instructions  Huge storage capacity  Cheaper than Primary Storage  Slower than Primary Storage  Magnetic and optical storage media

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc Secondary Storage Types  Magnetic tape  Cheap, slow, sequential access: good for backup  Magnetic Disk  Floppy  Hard disk  Zip drive  Memory Cards and Cartridges  Optical  CD-ROM, CD-RW  DVD  FMD-ROM

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc Storage for the Enterprise  Enterprise Storage Systems – provide coordinated, secure, managed storage for all enterprise data.  Redundant array of independent disks (RAID)  Storage area network  Network-attached storage  Storage Service Providers – third party storage utilities

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc Computer Classifications  Computers are commonly classified by their processing power:  Supercomputers  Mainframes  Midrange  Workstations  Microcomputers  Computing appliances  Classification boundaries are blurred.

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc Computer Classifications

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc Input Technology Input Devices Secondary Storage Output Devices Control Unit Primary Storage ALU Registers The CPU Communication Devices

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc Input Technologies  Human-oriented  Keyboard  Mice / trackball  Touch screens  Stylus  Joystick  Microphone  Automated  ATMs  POSs  Optical Scanners OMR MICR OCR  Voice recognition  Sensors  Cameras

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc Output Technology Input Devices Secondary Storage Output Devices Control Unit Primary Storage ALU Registers The CPU Communication Devices

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc Output Technologies  Monitors  Printers  Voice  Multimedia

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc Strategic Hardware Issues  Productivity  Will employees’ personal productivity increase as microprocessor power and speed increases?  Changing Work Styles  Will new work styles will benefit employees and the firm as a whole?  New Products and Services  Is the organization ready and able to take advantage of the new products and services that hardware advances may make possible for the business?  Improved Communication  Is the organization ready to use multimedia for knowledge sharing?

Introduction to Information Technology, 2 nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc Chapter Summary  Basic role and function of the CPU  Primary and secondary storage  Classifications of computers based on processing power  Variety and purpose of input devices  Variety and purpose of output devices  Consideration of strategic issues raised by the advances in hardware technology

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