Cisco Networking Academy Program CCNA 1 and 2 Companion Guide, Revised part 5 is the Cisco approved textbook to use alongside version of the Cisco Networking Academy Program CCNA 1 and CCNA 2 web-based courses. The topics covered provide you with the necessary knowledge to begin your preparation for the CCNA certification exam (640-801, or 640-821 and 640-811) and to enter the field of network administration. | Page 9 Tuesday May 20 2003 2 53 PM PC Basics 9 Figure 1-3 Motherboard Read-only memory ROM A type of computer memory in which data has been prerecorded. After data has been written onto a ROM chip it cannot be removed and can only be read. A version of ROM known as EEPROM electronically erasable programmable read-only memory can be written to. It is called Flash memory or firmware. The basic input output system BIOS in most PCs is stored in EEPROM. Expansion slot An opening in a computer usually on the motherboard where an expansion card can be inserted to add new capabilities to the computer see Figure 1-4 . System unit The main component of the PC system. It includes the case chassis power supply microprocessor main memory bus expansion cards disk drives floppy CD hard disk and so on and ports. The system unit does not include the keyboard the monitor or any other external devices connected to the computer. Power supply Supplies power to a computer. Page 10 Tuesday May 20 2003 2 53 PM 10 Chapter 1 Introduction to Networking Figure 1-4 Expansion Slot NOTE Motherboard Components The motherboard is the computer s main circuit board. It is crucial because it is the Some computers have a network card sound card video card and other cards integrated into the motherboard. nerve center of the computer system. Everything else in the system plugs into it is con- trolled by it and depends on it to communicate with other devices in the system. The following list describes the motherboard s various components Backplane A large circuit board that contains sockets for expansion cards. Memory chips RAM chips on memory cards plug into the motherboard. Network interface card NIC A printed circuit board that provides network communication capabilities to and from a PC. Many newer desktop and laptop computers have an Ethernet NIC built into the motherboard. Video card A board that plugs into a PC to give it display capabilities. Video cards typically include .
