User`s guide

BIOS POST Codes B-5
POST Code Description
F4h Output one beep
F5h Clear Huge Segment
F6h Boot to Mini DOS
F7h Boot to Full DOS
If 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 fi rst 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.