Specifications

System BIOSCBI/CGI Technical Reference
Chassis Plans 3-1
Chapter 3 System BIOS
BIOS OPERATION Sections 3 through 8 of this manual describe the operation of the American Megatrends
AMIBIOS and the AMIBIOS Setup Utility. Refer to Running AMIBIOS Setup later in
this chapter for standard Setup screens, options and defaults. The available Setup
screens, options and defaults may vary if you have a custom BIOS.
When the system is powered on, AMIBIOS performs the Power-On Self Test (POST)
routines. These routines are divided into two phases:
1) System Test and Initialization. Test and initialize system boards for
normal operations.
2) System Configuration Verification. Compare defined configuration with
hardware actually installed.
If an error is encountered during the diagnostic tests, the error is reported in one of two
different ways. If the error occurs before the display device is initialized, a series of
beeps is transmitted. If the error occurs after the display device is initialized, the error
message is displayed on the screen. See BIOS Errors later in this section for more infor-
mation on error handling.
The following are some of the Power-On Self Tests (POSTs) which are performed when
the system is powered on:
• CMOS Checksum Calculation
• Keyboard Controller Test
• CMOS Shutdown Register Test
• 8254 Timer Test
• Memory Refresh Test
• Display Memory Read/Write Test
• Display Type Verification
• Entering Protected Mode
• Memory Size Calculation
• Conventional and Extended Memory Test
• DMA Controller Tests
• Keyboard Test
• System Configuration Verification and Setup
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NOTE: When you perform a warm boot by pressing <Ctrl> + <Alt> + <Del>, all
memory tests are bypassed.
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AMIBIOS checks system and cache memory and reports them on both the initial
AMIBIOS screen and the AMIBIOS System Configuration screen which appears after
POST is completed. AMIBIOS attempts to initialize the peripheral devices by verifying