DECstation 5000/260, Руководство оператора, Страница: 117 / 215

8.2 Main Parts of the System Unit
8.2.3 Nonvolatile Random-Access Memory (NVRAM) Module
Your workstation optionally comes with 1 megabyte of nonvolatile random-
access memory (NVRAM). NVRAM provides a battery-backed-up memory
disk cache that retains data during a power failure and improves workstation
performance. The NVRAM module plugs into the last memory module slot
on the base system module. See Chapter 9 for instructions on installing an
NVRAM module.
8.2.4 The CPU Module
The CPU module performs all the data processing functions of the workstation.
It plugs into the base system module.
The CPU module contains
• R4000 central processing unit (CPU)
• 1-Mbyte instruction and data secondary cache
• 256 KD ROM that superceeds system ROM
For information on installing a CPU module, refer to Chapter 9.
8.2.5 TURBOchannel Option Modules
The system unit has space for up to three TURBOchannel option modules.
TURBOchannel option modules can expand the capabilities of your workstation
in the following ways:
• Graphics modules allow you to connect one or more monitors to your
workstation. Your workstation comes with one graphics option module
installed. Graphics modules can be installed in:
Any TURBOchannel option slot in the system unit
A TURBOchannel extender (TCE) unit connected to the system unit
• SCSI controller modules allow you to connect more external storage devices
(such as disk, tape, and compact disc drives) to your workstation than the
base system SCSI controller can accommodate.
• Ethernet controller modules allow you to connect your workstation to more
than one Ethernet network.
• Other TURBOchannel option modules allow you to connect special options,
such as DECaudio and DECvideo-in, to your workstation.
8–4 Inside the System Unit