Indd 289 121409 24914 pm all in one comptia network

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Unformatted text preview: rminology, and practices 289 ch08.indd 289 12/14/09 2:49:14 PM All-In-One / CompTIA Network+ All-in-One Exam Guide / Meyers & Jernigan / 170133-8 / Chapter 8 CompTIA A+Certification All-in-One Exam Guide 290 Historical/Conceptual Structure and Function of the Expansion Bus As you’ve learned, every device in the computer—whether soldered to the motherboard or snapped into a socket—connects to the external data bus and the address bus. The expansion slots are no exception. They connect to the rest of the PC through the chipset. Exactly where on the chipset varies depending on the system. On some systems, the expansion slots connect to the Southbridge (Figure 8-1). On other systems, the expansion slots connect to the Northbridge (Figure 8-2). Finally, many systems have more than one type of expansion bus, with slots of one type connecting to the Northbridge and slots of another type connecting to the Southbridge (Figure 8-3). Figure 8-1 Expansion slots connecting to Southbridge Figure 8-2 Expansion slots connecting to Northbridge The chipset provides an extension of the address bus and data bus to the expansion slots, and thus to any expansion cards in those slots. If you plug a hard drive controller card into an expansion slot, it functions just as if it were built into the motherboard, albeit with one big difference: speed. As you’ll recall from Chapter 5, “Microprocessors,” ch08.indd 290 12/14/09 2:49:15 PM All-In-One / CompTIA Network+ All-in-One Exam Guide / Meyers & Jernigan / 170133-8 / Chapter 8 All-In-One Chapter 8: Expansion Bus 291 Figure 8-3 Expansion slots connecting to both Northbridge and Southbridge the system crystal—the clock—pushes the CPU. The system crystal provides a critical function for the entire PC, acting like a drill sergeant calling a cadence, setting the pace of activity in the computer. Every device soldered to the motherboard is designed to run at the speed of the system crystal. A 133-MHz motherboard, for example, has at least a 133-MHz Northbridge chip and a 133-MHz South...
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This note was uploaded on 04/27/2010 for the course COMPTIA 1201 taught by Professor N/a during the Spring '10 term at Galveston College.

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