Service manual
System Overview 1-1
Chapter 1
System Overview
The Compaq AlphaServer DS20 system consists of up to two CPUs, up to 4 Gbytes of
memory, 6 I/O slots, and up to 7 SCSI storage devices. AlphaServer DS20 systems
can be mounted in a standard 19” rack.
AlphaServer DS20 systems support OpenVMS, Compaq Tru64 UNIX, Windows NT,
and Linux.
Topics in this chapter include the following:
•
System Enclosure
•
Operator Control Panel and Drives
•
System Consoles
•
System Architecture
•
CPU Types
•
Memory
•
Memory Addressing and Data Location
•
System Board
•
Server Feature Module
•
Power Circuit and Cover Interlock
•
Power Supply
•
Power Up/Down Sequence
•
TIG Bus
•
Maintenance Bus (I
2
C Bus)
•
StorageWorks Drives