Home ·  Forums ·  About Us ·  Awards ·  Contact Us ·  Upgrade your BIOS
Click to scan for Bios Updates
BIOS PostCodes

Intel Motherboards:

AST BIOS Post Codes

AST introduced an enhanced BIOS in 1992 with 3 beeps before all early POST failure messages.  Otherwise, the most sifnificant digit of the POST code indicates the number of long beeps and the least significant digit indicates the short beeps.  After 20, this dosen't work.

00 Reserved; Beep and halt if error occurs
01 Test CPU registers
02 Test the 8042 keyboard controller buffer
03 Test the 8042 keyboard controller reset
04 Verify presence of keyboard and check communication
05 Read keyboard input port (WS386SX16)
06 Initialize system board support chipset
09 Test BIOS ROM checksum
0D Test 8254 programmable interrupt timer registers (13 short beeps)
0E Test ASIC registers (CLEM only, 14 short beeps)
0F Test CMOS RAM shutdown byte (15 short beeps)
10 Test DMA controller 0 registers
11 Test DMA controller 1 registers
12 Test DMA page registers (EGA.VGA vertical retrace failed)
13 EGA/VGA RAM test failed
14 Test memory refresh toggle (EGA/VGA CRT registers failed)
15 Test base 64KB memory
16 Set interrupt vectors in base memory
17 Initialize video
18 Test display memory
20 EISA bus board power on (EISA systems only)
30 Test programmable interrupt controller #1 mask register
31 Test programmable interrupt controller #2 mask register
32 Test programmable interrupt controller's for stuck interrupts
33 Test for stuck NMI (P386 25.33, P486, CLAM and EISA)
34 Test for stuck DDNIL status (CLEM only)
40 Test CMOS RAM backup battery
41 Calculate and verify CMOS checksum
42 Setup CMOS RAM options (except WS386SX16)
50 Test the protected mode
51 Test protected mode exceptions
60 Calculate RAM size
61 Test RAM
62 Test shadow RAM (WS386SX16, P386 25/33, P486, CLEM, EISA); test cache (P386/16)
63 Test cache memory (P386 25/33, P486, CLEM, EISA); copy video BIOS to shadow RAM (p386C, P386/16, WS386SX16)
64 Copy system BIOS to shadow RAM (P386 25/33, P486, CLEM,EISA); Copy video BIOS to shadow RAM (P386 16, WS386SX16)
65 Copy video BIOS to shadow RAM P386 25/33, P486, CLEM,EISA); Test cache (WS386SX16)
66 Test 8254 programmable interrupt timer channel 2 (P386 25/33, P486, EISA)
67 Initialize memory (Eagle only)

All information has been gathered with permission of the respective BIOS providers. Although Bios Central has used reasonable effort to ensure accuracy we are unable to verify all codes posted. Use at your own risk. Bios Central, or any person associated with Bios Central takes no responsibility for any dmage resulting from the use of this information.

Copyright © 1988 -  by Bob Hurt. All rights reserved. Bios Central is a trademark of Bob Hurt.

System Specific Diagnostic and POST Error Messages:

BIOS Related Pages:

BIOS Beep Codes:

Free Stuff:

My Other Pages: