AST BIOS Post Codes - BIOS Central

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.