Chapter Overview • Computer Cases • Motherboards • ROM BIOS
The Computer Case • The case helps contain electromagnetic interference (EMI). • Larger cases usually have more expansion capability and are easier to work with. • Smaller cases usually have less expansion potential and support fewer internal devices. • Cases with more features cost more. • You should never run a computer with an open case.
Working with Cases Desktop Tower
The Motherboard • Before replacing a motherboard, double-check all other components to verify that the motherboard is the problem. • Replace rather than repair a damaged motherboard. • Consider purchase and interoperability issues.
Chip Sets • The chip set helps the CPU manage and control the computer. • The CPU must be compatible with the chip set. • Specialized chips control cache memory and high-speed buses. • Different chip sets have different on-board components. • On-board components might have fewer features than do expansion card versions.
ROM BIOS Chips • Read-only memory (ROM) chips store basic input/output system (BIOS) data—even when the computer power is off. • The system BIOS prepares the hardware to run. • Classes of BIOS chips include: • Core chips • Updateable complementary metal-oxide semiconductor (CMOS) chips • Other chips with their own BIOS data
Information Stored in the CMOS • Floppy disk and hard disk drive types • CPU type and speed • Random access memory (RAM) size • Date and time • Serial and parallel port information • Plug and Play information • Power-saving settings
Determining the BIOS Manufacturer • Watch the monitor when the computer boots. • Check the computer or motherboard manual. • Remove the computer cover and look at the chip. • Use a third-party utility program. • Cause an error that will launch the setup program.
The Most Common Ways to Access BIOS Setup Programs • AMI: Press Delete when the machine begins to boot. • Phoenix: Press Ctrl+Alt+Esc, Delete, or F2 when requested. • Award: Follow the procedure for AMI or Phoenix.
Maintaining CMOS • CMOS data can be lost for several reasons. • You should write down CMOS setup information or back it up. • Plug and Play devices include their own BIOS information.
The CMOS Battery • Look for battery requirements on the motherboard or in the documentation. • Expect 2–7 years of battery life, depending on the type of battery. • Watch for battery failure indicators. • Replace the battery if a computer loses stored CMOS information more than once in a week.
All Other Chips • Add-on boards may have ROM chips with their own BIOS data. • Device drivers could be required to provide BIOS support for hardware.
Power-On Self Test • The power-on self test (POST) checks every primary device at startup. • Beep codes indicate problems before and during the video test. • Errors displayed on the screen typically indicate problems after the video test. • Errors can be fatal or nonfatal. • POST cards display codes that you can decode from the manufacturer’s manual.
Chapter Summary • You should select a computer case for ease of use and expandability. • EMI can harm surrounding equipment. • Motherboards use different chip sets with differing capabilities. • ROM BIOS chips can be static or updateable. • A CMOS program accesses BIOS information stored in CMOS chips. • If you change hardware, you must update the CMOS to reflect changes. • A CMOS battery ensures that CMOS information is saved.