Technical Reference Guide
Compaq iPAQ Family of Internet Devices
First Edition - March 2000
8-7
8.2.6 FLASH ROM FUNCTIONS
The system BIOS may be upgraded by flashing the ROM using the INT 15, AX=E822h BIOS
interface, whi ch includes the n ecessary subfunctions. An upgrade utility is provided on a
ROMPAQ diskette.
8.2.7 POWER BUTTON FUNCTIONS
The BIOS includes an interface for controlling the system units power button. The power button
can be disabled an d 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 th e ROM flashing proced ure to reduce the cha nce of an accidental p ower 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 Disa ble function invoked th e 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
Re
et
tu
ur
rn
n:
:
(
(S
Su
uc
cc
ce
es
ss
sf
fu
ul
l)
)
CF = 0
AH = 00
(Failure)
CF = 1
AH = 86, call not supported