Chapter 9 Basic Settings of BIOS 9.1 What is BIOS 9.2 BIOS Program Interface 9.3 Award BIOS Basic Settings 9.4 AMI BIOS Basic Settings 9.5 BIOS upgrade 9.1 What is BIOS 9.1.1 Understanding BIOS 9.1.2 Understanding CMOS Differences between 9.1.3 BIOS and CMOS Basic functions of 9.1.4 BIOS When will BIOS be set up in 9.1.5 Classification of 9.1.6 BIOS 9.1.1 Understanding BIOS BIOS is called "basic input/output system" because it contains the m ost important input/output program, system settings information, bo ot-up power-on self-check program and system start-up self-check progr am in the computer system. These programs are solidified in a memory (chip) on the motherboard. This chip is read-only memory, commonly kn own as BIOS chip, also known as ROM-BIOS core.Slice, as shown in the f ollowing figure. 9.1.2 Understanding CMOS A readable chip made of CMOS (Complementary Metal Oxide Semico nductor) material is used by computer manufacturers to save the har dware configuration of the system and the settings of some paramete rs by users. It is a technology for making large scale integrated circuit chips and produces a readable and writable RAM chip, which is called CMOS RAM.This chip holds the basic startup information of the computer system, such as date, time, startup settings, etc.When the system boots the computer on power, it must read the information in CMOS to initialize the components of the computer. CMOS RAM is characterized by low power consumption, random reading or writing of data. It is powered by a button battery on the main board. As shown in the figure below, this button battery is the backup battery of the system, which continues to power CMOS when the system is powered down, so that information in CMOS can be saved.If there is a problem with this battery, the information in CMOS will be lost and the system will not be able to start. 9.1.3 Differences between BIOS and CMOS Beginners often don't understand the difference between BIOS and CMOS. In f act, BIOS and CMOS are two completely different concepts. BIOS is a set of co mputer programs used to set hardware, i.e. interrupt instruction system. The pr ogram is stored in an EPROM or EEPROM chip on the motherboard, which contains important information of the system and setting program of system parameters (BIOS Setup program). CMOS is a readable RAM chip on the motherboard, which contains specific paramet ers about system configuration. It is used to save the hardware configuration and se tting information of the current system and user's setting parameters of BIOS. Its co ntent can be read and written by program, and CMOS RAM chip is powered by back up batteries, even if the system is powered down, the information will not be lost. BIOS and CMOS are related and different. The system setup program in BIOS is the means to complete the setting of CMOS parameters. CMOS RAM is not only the stor age place for setting system parameters by BIOS, but also the result of setting syste m parameters by BIOS.Therefore, the complete statement should be "setting CMOS parameters through BIOS setup program". 9.1.4 Basic Functions of BIOS The functions of BIOS are divided into three parts: self-check and initialization of system hardware, program service and processing of hardware interrupts. 1. Self-checking and initialization The boot-up self-check program (POST) is the program that BIOS s tarts first after boot-up. After boot-up, BIOS will test all hardware d evices of the computer. This process generally includes testing CP U, system motherboard, basic memory and extended memory, testi ng system ROM BIOS, testing system configuration in CMOS mem ory, initializing video controller, testing video memory and testing video signal.With synchronous signal, CRT interface is tested, key board, floppy drive, hard disk and CD-ROM subsystem are checke d, parallel port (printer) and serial port (RS232) are checked. 2. Program Services Program services are mainly for applications and operating syste ms and other software services.BIOS deals directly with compute r I/O devices, and sends commands through specific data ports t o transmit or receive data from various external devices.The soft ware program completes the operation of hardware through BIOS , such as reading data from disk and transmitting it to printer or f ax machine, or directly inputting material into computer through scanner. 3. Setting Interrupts Setting interrupt is also called hard