Compaq AP200 - Professional - 128 MB RAM Reference Manual page 55

3-18 Intelligent Manageability
FailSafe Boot Block ROM
The FailSafe Boot Block ROM allows for system recovery in the unlikely
event of a ROM flash failure, for example, if a power failure occurs during a
ROM upgrade. The Boot Block is a flash-protected section of the ROM that
checks to validate the system ROM each time power to the system is turned
on.
If the system ROM is valid, the system starts normally.
If the system ROM fails the validation check, the FailSafe Boot Block
ROM provides enough support to start the system from a user ROMPaq
diskette, which will program the system ROM with a valid image.
Because there is no video or hard drive support from the Boot Block ROM,
the keyboard lights communicate information. When the Boot Block detects
an invalid system ROM, the system sounds a series of beeps (one long and
three short) and flashes the three keyboard lights.
To recover the system after hearing the FailSafe Boot Block beeps, complete
the following steps:
1. Remove any diskettes from the diskette drive and turn off the power.
2. Insert a user ROMPaq diskette into the diskette drive.
3. Turn on power to the system.
If a Setup password has been established, the Caps Lock light will turn
on.
4. Enter the Setup password.
If the system successfully starts from the diskette and successfully
reprograms the ROM, then the three keyboard lights will turn on. A
"rising tone" series of beeps also signals successful completion.
IMPORTANT: The workstation ships with the diskette drive enabled. If the
diskette drive is disabled, the FailSafe Boot Block ROM will override the
disabled component to accommodate a system ROM recovery in the event a
system ROM failure occurs.