1. Copyright 2003 The McGraw-Hill Companies, Inc. 1 66 CHAPTER The System Unit computing ESSENTIALS    

2. Copyright 2003 The McGraw-Hill Companies, Inc. 2 Competencies System Clock Cards and buses Ports and cables computing ESSENTIALS    

3. Copyright 2003 The McGraw-Hill Companies, Inc. 3 System Clock Special chip that produces precise electrical impulses Used to coordinate and synchronize computer operations Expressed in megahertz or gigahertz Faster clock speed, faster computer computing ESSENTIALS    

4. Copyright 2003 The McGraw-Hill Companies, Inc. 4 Expansion Slots and Cards An expansion slot is a long, narrow socket on the motherboard into which an expansion card can be inserted. Expansion cards act like an interface circuit for a computer peripheral device. These cards provide the computer an ability to control a peripheral device (input or output).

5. Copyright 2003 The McGraw-Hill Companies, Inc. 5 Expansion Cards Expansion cards used to connect to devices outside the system unit Controller cards, Adapter cards, Interface cards, plug-in boards Usually have ports to connect the card to a device outside the system unit computing ESSENTIALS    

6. Copyright 2003 The McGraw-Hill Companies, Inc. 6 Types of Expansion Cards Network interface cards (NIC) Modem cards Sound cards Video cards SCSI adapter TV tuner cards PCMCIA cards computing ESSENTIALS    

7. Copyright 2003 The McGraw-Hill Companies, Inc. 7 Card Configuration Settings For installing a new device, following setup is needed: Inserting the device card into the matching slot Installing the device driver program for the device Configure the system (tedious step, requires sufficient technical background) “Plug and Play” is a new technology for making the device installation procedure much faster and easier.

8. Copyright 2003 The McGraw-Hill Companies, Inc. 8 “Plug and Play” Hardware and software standards Makes system expansion easy for the user Automatically installs drivers and system configuration System unit recognizes the new device computing ESSENTIALS     A plug-n-play card requires the user to: Switch off the system Insert the card Open the system again. System automatically configure itself for the newly installed device - User is asked for the latest device driver.

9. Copyright 2003 The McGraw-Hill Companies, Inc. 9 Bus Lines More lines, the faster data can travel 64 bit data bus is faster than a 32 bit Data pathways that link parts of the CPU together and components to the CPU computing ESSENTIALS    

10. Copyright 2003 The McGraw-Hill Companies, Inc. 10 Principal Bus Architectures Industry Standard Architecture (ISA) Peripheral Component Interconnect (PCI) Advanced Graphic Port (AGP) Universal Serial Bus (USB) High performance Serial Bus (HPSB) computing ESSENTIALS    

11. Copyright 2003 The McGraw-Hill Companies, Inc. 11 ISA Bus Developed by IBM for personal computers Slow Originally 8 bit, later expanded to 16 bit Still used by some expansion cards Replaced by PCI bus in the near future computing ESSENTIALS    

12. Copyright 2003 The McGraw-Hill Companies, Inc. 12 PCI Bus Originally developed to meet demands of graphical user interfaces High speed 32 bit or 64 bit Widely used to connect CPU, memory, and expansion cards computing ESSENTIALS    

13. Copyright 2003 The McGraw-Hill Companies, Inc. 13 AGP Bus Dedicated bus for acceleration of graphics performance Replacing the PCI bus for transfer of video data computing ESSENTIALS    

14. Copyright 2003 The McGraw-Hill Companies, Inc. 14 Other Bus Types USB Connects directly to the PCI bus on the motherboard Supports external devices without inserting expansion cards for each device HPSB FireWire Similar to USB but faster computing ESSENTIALS    

15. Copyright 2003 The McGraw-Hill Companies, Inc. 15 Ports Four common port types Serial Parallel USB FireWire computing ESSENTIALS     Sockets that connect external devices to the system unit

16. Copyright 2003 The McGraw-Hill Companies, Inc. 16 Serial & Parallel Ports Serial Port Data sent one bit at a time Good long distance transmission of data Parallel Port Data sent 8 bits simultaneously Used for short distances computing ESSENTIALS    

17. Copyright 2003 The McGraw-Hill Companies, Inc. 17 USB and HPSB Ports USB Port Replacing serial and parallel ports Faster Each port can support more than one device HPSB Port FireWire ports Faster then USB ports computing ESSENTIALS    

18. Copyright 2003 The McGraw-Hill Companies, Inc. 18 Cables Connect Input/Output devices Mouse Keyboard Printer Monitor Newer cables AGP graphics monitor USB joy stick; scanner HPSB video camera computing ESSENTIALS    

19. Copyright 2003 The McGraw-Hill Companies, Inc. 19 Look to the Future Wireless Technology and PDAs Personal wearable computer POMA ® Wireless pointing device, head mounted display Developed by Xybernaut Corporation Currently being evaluated for use in airport security computing ESSENTIALS    