© Copyright IBM Corp. 1998 215
Chapter 8. Hints and Tips
This chapter provides useful hints and tips, not only for the Models 150 and
260, but for all RS/6000 models.

8.1 Electronic Key-Switch Function

One of the main differences between Micro Channel-based RS/6000 systems
and PCI-based RS/6000 systems is the omission of a physical key. On all
Micro Channel-based RS/6000 systems, there is a physical key that can be in
one of three positions:
• Normal
•Service
• Secure
Although the Models 150 and 260 (and also the other PCI-based RS/6000
models) do not have this physical key, they have an electronic key-switch
instead. Currently, this provides the ability to boot the machine in Normal or
Service mode. The electronic key-switch is a logical key-switch, separate
from a physical one, that the platform firmware knows about. Its state is
communicated from the firmware to AIX through a residual data environment
variable. Currently, only the firmware can set the electronic key-switch.

8.1.1 bootlist Command

The bootlist command can be used to alter or display the boot list. For
example, you can set the customized boot list with the following command:
# bootlist -m normal hdisk0
This would set the customized boot list in the NVRAM to hdisk0. hdisk0 would
then be used to attempt a boot in Normal mode.
The service bootlist can be determined with the command:
# bootlist -m service -o
The output is as follows and depends on your settings:
fd0
cd0
rmt0
hdisk0
ent0