1. Chapter 4 Information Technology in Business: Hardware

2. 2 The Central Tool of Modern Information Systems Four Basic Functions of Computers Accept data Process data Store data and instructions Output data

3. 3 All computers have the same basic components.

4. 4 Organizations have moved from using large mainframes to using networked PCs. The Central Tool of Modern Information Systems

5. 5 Computers Communicating: Bits And Bytes Computer recognizes two states: on or off Each on or off signal represents a bit (binary digit)

6. 6 A Peek Inside the Computer Figure 4.6 A look inside a computer

7. 7 A Peek Inside the Computer The Central Processing Unit (CPU) The brain of the computer Microprocessor Carries signals that execute all processing Two Components: Control unit Arithmetic logic unit (ALU)

8. 8 Microprocessor Silicon chip embedded with transistors, or semiconductors letter D : 11000100 Schematic of how circuits on a chip would be open and closed to represent the letter D in EBCDIC (11000100)

9. 9 What happens inside the CPU in one machine cycle executing the operation 7 + 5 –CPU’s execution of four functions: 1.Fetch 2. Decode 3.Execute 4. Store

10. 10 Machine Cycle CPU’s execution of four functions: Fetch Decode Execute Store Functions measured in small fractions of a second

11. 11 Memory Internal Memory Random access memory (RAM) Read-only memory (ROM) External Memory Magnetic disks, magnetic tapes, optical discs TYPES OF MEMORY

12. 12 Computer Power Clock rate (measured in cycles per second) Amount of information the CPU can process per second 1Mhz= 1 million Machine Cycle Speed determined only by combination of both factors Computer Power

13. 13 Input Devices Keyboard Mouse, Trackball, and Track Pad Touch Screen Source Data Input Devices Imaging Speech Recognition

14. 14 Output Devices Soft-Copy Output Devices Cathode-Ray Tube (CRT) Monitor Flat-Panel Monitor Speech Output Hardcopy Output Devices Nonimpact Printers (most common) Impact Printers

15. 15 External Storage Media Important Properties to Consider Capacity Speed Cost

16. 16 External Storage Media Magnetic Tapes Magnetic Disks Optical Discs (Compact Discs) Optical Tapes

17. 17 External Storage Media

18. 18 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

19. 19 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

20. 20 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.

21. 21 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

22. 22 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 Considerations in Purchasing Hardware

23. 23 SEQUENTIAL & PARALLEL PROCESSING SEQUENTIAL PARALLEL TASK 1 RESULT TASK 2 RESULT Program CPU Program CPU Program CPU TASK 2 CPU TASK 3 CPU TASK 1 RESULT

24. 24 CLIENT SERVER REQUESTS DATA, SERVICE USER INTERFACE APPLICATION FUNCTION DATA APPLICATION FUNCTION NETWORK RESOURCES CLIENT / SERVER