Bios Post Codes; Recoverable Post Errors; Terminal Post Errors - Acer AC100 Service Manual

BIOS POST Codes

This section lists the POST (Power-On Self-Test) codes for the AMI BIOS. POST codes are divided into two
categories: recoverable and terminal.

Recoverable POST Errors

When a recoverable type of error occurs during POST, the BIOS will display an POST code that describes the
problem. BIOS may also issue one of the following beep codes:
• One long and two short beeps - video configuration error
• One repetitive long beep - no memory detected

Terminal POST Errors

If a terminal type of error occurs, BIOS will shut down the system. Before doing so, BIOS will write the error to
port 80h, attempt to initialize video and write the error in the top left corner of the screen.
The following is a list of codes that may be written to port 80h.
Post Code Description
02h Verify Real Mode
03h Disable Non-Maskable Interrupt (NMI)
04h Get CPU type
06h Initialize system hardware
07h Disable shadow and execute code from the ROM.
08h Initialize chipset with initial POST values
09h Set IN POST flag
0Ah Initialize CPU registers
0Bh Enable CPU cache
0Ch Initialize caches to initial POST values
0Eh Initialize I/O component
0Fh Initialize the local bus IDE
10h Initialize Power Management
11h Load alternate registers with initial POST values
12h Restore CPU control word during warm boot
13h Initialize PCI Bus Mastering devices
14h Initialize keyboard controller
16h 1-2-2-3 BIOS ROM checksum
17h Initialize cache before memory Auto size
18h 8254 timer initialization
1Ah 8237 DMA controller initialization
1Ch Reset Programmable Interrupt Controller
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