DEC AlphaServer 2100, Owner'S Manual

Page: 71 / 192

Operator Control Panel (OCP)
DC On/Off
Button
DC On/Off
The DC On/Off button controls the flow of DC power to the
system. You use the DC On/Off button and the AC On/Off
switch, if present, to power the system up or down. The DC
On/Off light, located on the DC On/Off button, is lit whenever
DC power is present.
Halt Button Halt
The Halt button interrupts an operating system session if you
are running DEC OSF/1 or OpenVMS. The Halt light, located on
the Halt button, comes on briefly during the system self-tests.
Thereafter, the Halt light comes on and remains lit whenever DC
power is present and the Halt button is in the ‘‘in’’ position.
Before Power-Up: Pressing the Halt button to the ‘‘in’’ position
before you power up the system boots the SRM console and
prevents the operating system from booting.
• To boot the DEC OSF/1 or OpenVMS operating system, the
Halt button must be in the ‘‘out’’ position (not lit).
• To boot the Windows NT operating system, the Halt button
must be in the ‘‘out’’ position and you must enter the
arc
command at the SRM console to invoke the ARC console and
access the Boot menu.
Invoking Console Mode: Pressing the Halt button during a
DEC OSF/1 or OpenVMS operating system session invokes the
SRM console. Pressing the Halt button during a Windows NT
session has no effect.
Caution
Pressing the Halt button interrupts your DEC OSF/1 or
OpenVMS operating system session. Before pressing the
Halt button, shut down your operating system according
to the operating system shutdown procedure described in
your operating system documentation.
Hardware Components 2–3