SBA-7142G-T4 Blade Module User’s Manual
A-4
A-2 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.

Uncompressed Initialization Codes

The uncompressed initialization checkpoint codes are listed in order of execution in
table Table A-2.
TableA-2. Uncompressed Initialization Error Codes
Post Code Description
D0h The NMI is disabled. Power on delay is starting. Next, the initialization
code checksum will be verified.
D1h Initializing the DMA controller, performing the keyboard controller BAT
test, starting memory refresh and entering 4 GB flat mode next.
D3h Starting memory sizing next.
D4h Returning to real mode. Executing any OEM patches and setting the
Stack next.
D5h
Passing control to the uncompressed code in shadow RAM at
E000:0000h. The initialization code is copied to segment 0 and control
will be transferred to segment 0.
D6h
Control is in segment 0. Next, checking if <Ctrl> <Home> was pressed
and verifying the system BIOS checksum. If either <Ctrl> <Home> was
pressed or the system BIOS checksum is bad, next will go to checkpoint
code E0h. Otherwise, going to checkpoint code D7h.