Appendix B: BIOS POST Codes
B-5
POST Code
Description
CDh
Re-map I/O and memory for PCMCIA
CEh
Initialize digitizer and display message
D2h
Unknown interrupt
The following are for boot block in Flash ROM
POST Code
Description
E0h
Initialize the chipset
E1h
Initialize the bridge
E2h
Initialize the CPU
E3h
Initialize system timer
E4h
Initialize system I/O
E5h
Check force recovery boot
E6h
Checksum BIOS ROM
E7h
Go to BIOS
E8h
Set Huge Segment
E9h
Initialize Multi Processor
EAh
Initialize OEM special code
EBh
Initialize PIC and DMA
ECh
Initialize Memory type
EDh
Initialize Memory size
EEh
Shadow Boot Block
EFh
System memory test
F0h
Initialize interrupt vectors
F1h
Initialize Run Time Clock
F2h
Initialize video
F3h
Initialize System Management Manager
F4h
Output one beep
F5h
Clear Huge Segment
F6h
Boot to Mini DOS
F7h
Boot to Full DOS
* If the BIOS detects error 2C, 2E, or 30 (base 512K RAM error), it displays an additional
word-bitmap (
xxxx
) indicating the address line or bits that failed. For example, “2C 0002”
means address line 1 (bit one set) has failed. “2E 1020" means data bits 12 and 5 (bits
12 and 5 set) have failed in the lower 16 bits. The BIOS also sends the bitmap to the port-
80 LED display. It first displays the checkpoint code, followed by a delay, the high-order
byte, another delay, and then the loworder byte of the error. It repeats this sequence
continuously.
