IBM PS/2 90 XP 486 Hardware Maintenance Reference page 49

6.1 Installation Requirements
Warning: The power-on password must be removed prior to installing the new
IML code.
Notes:
1. Before you install the new version of the System Diskettes, tell the
customer that the installation takes up to one hour.
2. Follow all of the instructions in order.
You will need the following:
A pen or pencil and a blank sheet of paper.
The original option diskettes for all the options installed in the
system. If the customer does not have all of the option diskettes,
use a current backup of the System Partition.
As many as four blank 2.0MB diskettes that are not write protected.
IBM PS/2 Model 90 XP 486 and 95 XP 486 HMR
Installation Requirements
¦ Copyright IBM Corp. 1990, 1992
6.1 - 1