Computer Hardware

1. Computer Hardware • In this lecture, 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.

2. The Central Processing Unit (CPU) The CPU Control Unit ALU Input Devices Output Devices Registers Primary Storage Communication Devices Secondary Storage

3. The CPU Control Unit ALU Registers Primary Storage The CPU (continued) • A microprocessor that executes instructions to perform processing tasks. Component parts are: • Control Unit • Arithmetic-Logic Unit • Registers • Primary Storage

4. The CPU Control Unit ALU Registers Primary Storage The CPU (continued) • Control Unit • Access program instructions • Decode (interpret) instructions • Control flow of data throughout system • Data flows through paths called buses

5. The CPU Control Unit ALU Registers Primary Storage The CPU (continued) • Arithmetic-Logic Unit • Perform computations on data • Perform comparisons on data

6. The CPU Control Unit ALU Registers Primary Storage The CPU (continued) • Registers • High speed storage areas • Hold data and instructions

7. The CPU Control Unit ALU Registers Primary Storage The CPU (continued) • Primary Storage (Main Memory) • Stores instructions from programs • Stores data to be processed

8. 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.

9. 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

10. 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.

11. Computer Memory The CPU Control Unit ALU Input Devices Output Devices Registers Primary Storage Communication Devices Secondary Storage

12. 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

13. 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

14. 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

15. 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

16. 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

17. 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

18. Computer Classifications • Computers are commonly classified by their processing power: • Supercomputers • Mainframes • Midrange • Workstations • Microcomputers • Computing appliances • Classification boundaries are blurred.

19. Computer Classifications

20. Input Technology The CPU Control Unit ALU Input Devices Output Devices Registers Primary Storage Communication Devices Secondary Storage

21. Human-oriented Keyboard Mice / trackball Touch screens Stylus Joystick Microphone Automated ATMs POSs Optical Scanners OMR MICR OCR Voice recognition Sensors Cameras Input Technologies

22. Output Technology The CPU Control Unit ALU Input Devices Output Devices Registers Primary Storage Communication Devices Secondary Storage

23. Output Technologies • Monitors • Printers • Voice • Multimedia

24. 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?

25. Lecture 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