Specifications

Table 2–2 (Cont.) POST and Boot Messages
POST No. Error Name Description Solution
001 Not a bootable diskette The diskette in
drive A is not
formatted as a
bootable diskette.
Replace the
diskette with a
bootable diskette
and try again.
000 Boot Diskette read failure No diskette in drive
A. Insert a diskette
and try again.
2.3.5 Beep Codes
If POST finds an error and cannot display a message, the system board speaker
beeps to indicate the error and places a value in I/O port 80h. For example, a
failure of bit 3 in the first 64 KB of DRAM is indicated by a 2-1-4 beep code (a
burst of two beeps, a single beep, and a burst of four beeps).
Tables 2–3 and 2–4 list the beep codes and the values POST writes to I/O port
80h when it encounters an error. Table 2–3 lists fatal errors (errors that lock
the computer), and Table 2–4 lists nonfatal errors (errors that do not lock the
computer).
One beep code is not listed in either table: a long beep followed by one or more
short beeps. This beep code indicates a video controller failure.
Table 2–3 Beep Codes for Fatal Errors
Beep
Code Error Message Port 80h
1-1-3 Real-time clock write/read failure 02h
1-1-4 ROM BIOS checksum failure 03h
1-2-1 Programmable interval timer failure 04h
1-2-2 DMA initialization failure 05h
1-2-3 DMA page register write/read failure 06h
1-3-1 DRAM refresh verification failure 08h
(continued on next page)
2–16 System Troubleshooting