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PC Specialist's Handbook
Beep codes
Whenever a recoverable error occurs during Power-On Self Test (POST), the BIOS displays an error message
describing the problem. The BIOS also issues a beep code (one long tone followed by two short tones) during
POST if the video configuration fails (no card installed or faulty) or if an external ROM module does not properly
checksum to zero.
An external ROM module (e.g video BIOS) can also issue audible errors, usually consisting of one long tone
followed by a series of short tones. For more information on the beep codes issued, check the documentation
for that external device.
There are several POST routines that issue a POST Terminal Error and shut down the system if they fail.
Before shutting down the system, the terminal-error handler issues a beep code signifying the test point error,
writes the error to I/O port 80h, attempts to initialize the video and writes the error in the upper left corner of the
screen (using both mono and color adapters).
If POST completes normally, the BIOS issues one short beep before passing control to the operating system.
List of Beep Codes:
Beeps
80h Code
1
B4h
1-2
98h
1-2-2-3
16h
1-3-1-1
20h
1-3-1-3
22h
1-3-3-1
28h
1-3-3-2
29h
1-3-3-3
2Ah
1-3-4-1
2Ch
1-3-4-3
2Eh
1-4-1-1
30h
2-1-2-2
45h
2-1-2-3
46h
2-2-3-1
58h
2-2-4-1
5Ch
Edition 1 - Release 1 - March 1998
Description
One short beep before boot
Search for option ROMs
BIOS ROM checksum
Test DRAM refresh
Test keyboard controller
Autosize DRAM
Initialise POST Memory Manager
Clear 512 kB base RAM
RAM failure on address line xxxx*
RAM failure on data bits xxxx* of low byte of memory
bus
RAM failure on data bits xxxx* of high byte of memory
bus
POST device initialisation
Check ROM copyright notice
Test for unexpected interrupts
Test RAM between 512 and 640 kB
ErgoPro m664-series
Page 5-3
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