User`s guide

Overview 1-3
The AlphaServer DS20 is a switch-based interconnect system using a cross-bar
switch chipset that allows data to move directly from place to place in the system.
Figure 1–1 is a block diagram showing the various data paths through the switch.
The pedestal enclosure contains the system and allows for up to ten internal storage
devices: one dedicated diskette drive slot, two removable media slots, and seven 3.5-
inch hard disk drives. All CPUs, memory and I/O components are on a single board
that contains the memory subsystem, two PCI buses, the ISA bus, the integrated I/O
controllers. The remote console manager (RCM) is on a separate server feature
module.
The control panel includes Halt, Reset, and On/Off buttons.
Supported Operating Systems
This system supports the following minimum revisions of these operating systems:
• Microsoft Windows NT 4.0 with service pack 3 or later
• OpenVMS 7.1-2
• DIGITAL UNIX 4.0E
The system runs in two modes. In program mode, the operating system controls the
system and manages the execution of application programs. In console mode, the
console program controls the system allowing control of system management
functions.
System Console Firmware
You perform many of the tasks for managing and configuring your server system in
console mode, where the system is controlled by the console subsystem, rather than
the operating system.
The console subsystem, located in ROM (read-only memory) on the system board,
contains the firmware that interacts directly with hardware components and
facilitates interaction between the hardware and the operating system.