Intel MB440LX manual Post Codes and Countdown Codes, Normal Port-80 Codes, Port 80 Code Reason

POST Codes and Countdown Codes

The BIOS indicates the current testing phase during POST after the video adapter has been successfully initialized by outputting a 2-digit hex code to I/O location 80h. If a port-80h ISA card is installed, it displays this 2-digit code on a pair of hex display LEDs.

Normal Port-80 Codes

These are the port-80 codes and countdown codes displayed during the normal BIOS POST process.

	Table 10-2. Port-80 Codes
Port 80 Code	Reason
02	Verify Real Mode
04	Get CPU type
06	Initialize system hardware
08	Initialize chipset registers with initial POST values
09	Set in POST flag
0A	Initialize CPU registers
0B	Enable CPU cache
0C	Initialize caches to initial POST values
0E	Initialize I/O
0F	Initialize the local bus IDE
10	Initialize Power Management
11	Load alternate registers with initial POST values new
12	Restore CPU control word during warm boot
14	Initialize keyboard controller
16	BIOS ROM checksum

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214 Chapter 10 Solving Problems