DEC VAX 4000 300 Manual page 21

• To maintain air flow integrity
CAUTION: Do not operate the system without Digital-supplied module
covers. The covers are required to protect the equipment and to meet
international regulatory standards. Do not substitute other module covers
as they may not meet the required specifications.
Operating the system without the module covers has the following
consequences:
• The system may overheat due to improper air circulation.
• The system will not comply with FCC and VDE requirements for
electrostatic shielding and may produce electrical interference that
affects other equipment.
• The system is susceptible to electrical interference or damage from
external sources.
The design of the module covers varies, depending on the type of module
installed in the slot. Modules requiring external cable connections, such as
communications controllers, have recessed covers that are riveted directly
to the module. The recessed module covers allow space for connecting
cables. Modules requiring no external cable connections, such as mass
storage controllers, are covered by flush covers.
covered by flush covers which may be single or double width. All covers,
except those covering empty slots, have a label identifying the module
installed in the slot.
Cables connecting your system to peripheral devices (such as terminals,
modems, and printers) are attached to communications controllers. Each
cable can contain multiple lines. The cables run under the BA440 enclosure
and out the back or side of the enclosure, where the cables are split into
individual lines. Chapter 3 describes these connections in more detail.
1.1.1.3 Console Module
Your system can have up to four memory modules. The memory modules
occupy the first four slots of the card cage and are followed by the CPU. The
memory and CPU modules are behind the console module that covers the
first five slots. The console module, shown in Section 1.1.1.3, has several
system controls and connectors.
Empty slots are also
System Overview 1–11