IBM PS/2 90 XP 486 Hardware Maintenance Reference page 12

2.2 Override Jumper
The override jumper J10 (Model 90) or J16 (Model 95) on the system board
is most often used to erase a power-on password.
also has multiple purposes.
powered-off, then power-on the system, it has the following effects on the
system:
Power-on Password: If the system has a power-on password, that password
is erased the first time the system is powered-on (after moving the
jumper).
Unattended Start Mode (server mode):
activated, then you power-off the system, move the jumper, then power-on
the system, the system bypasses that mode.
Unattended Start Mode is restored.
in the Unattended Start Mode).
Initial Program Load (IPL):
Selectable startup sequence utility, then you power-off the system, move
the jumper, then power-on the system, the system bypasses the customized
settings and starts with the default settings.
the customized startup settings are restored.
Initial Machine Load (IML):
Partition by default.
then you move the jumper, then power on the system, the system default is
bypassed and the system loads the IML image from the Reference Diskette.
After the first power-on, the system loads the IML from the System
Partition.
To activate the override feature, move the override jumper so that it
connects the center pin and the pin on the opposite end of the connector.
The next time you power-on the system, the override is activated (for that
one power-up). Leave the override jumper in that position until the next
time you need to use the override feature.
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
Override Jumper
If you move the jumper with the system
If the Unattended Start Mode is
After the first power-on, the
(Power-on password is required to run
If the startup sequence is customized via the
The system loads the IML from the System
If the Reference Diskette is in the diskette drive,
¦ Copyright IBM Corp. 1990, 1992
2.2 - 1
However, the same jumper
After the first power-on,