Technical Reference Guide
Compaq iPAQ Series of Desktop Personal Computers
Review Copy - January 2001
8-7
8.3.5 FLASH ROM FUNCTIONS
The system BIOS may be upgraded by flashing the ROM using the INT 15, AX=E822h BIOS
interface, which includes the necessary subfunctions. An upgrade utility is provided on a
ROMPAQ diskette.
8.3.6 POWER BUTTON FUNCTIONS
The BIOS includes an interface for controlling the system unit’s power button. The power button
can be disabled and enabled.
The INT 15, AX=E822h, BL=08h function can be invoked to disable the power button, preventing
a user from inadvertently powering down the system. This tri-modal function is typically used in
the ROM flashing procedure to reduce the chance of an accidental power down while the BIOS is
being upgraded.
Entry:
AX = E822h
BL = 08h
Return:
(Successful)
CF = 0
AH = 00
(Failure)
CF = 1
AH = 86, not supported
NOTE: With the Disable function invoked the system can still be powered down by
holding the power button in for four seconds or more.
The INT 15, AX=E822h, BL=09h function is used to restore the power button to the state it was in
prior to invoking the Disable (BL=08h) function.
Entry:
AX = E822h
BL = 09h
R
R
e
e
t
t
u
u
r
r
n
n
:
:
(
(
S
S
u
u
c
c
c
c
e
e
s
s
s
s
f
f
u
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)
)
CF = 0
AH = 00
(Failure)
CF = 1
AH = 86, call not supported
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