having a single module dedicated to one specific
The chassis or assemblies can be mounted in one of
several ways inside the computers frame or cabinet.
These include brackets that permit the chassis or
assembly to slide in and out of the frame or cabinet;
doors that swing out from one side of the frame or
cabinet; or a fixed chassis or assembly similar to a cage
or rack inside the frame or cabinet. In some cases, a
combination of two or more of these methods is used
by a single computer.
Chassis can slide out on
mounting hardware, swing open like a door, or be fixed.
Figure 2-11 is an illustration of a chassis or
The pcbs inside a chassis or assembly are arranged
in the same way as inside a module-in close proximity
and configured in rows. Again refer to the computers
technical manual for a chassis map that outlines the
location of all parts of the computer.
Each chassis or assembly contains subassemblies,
pcbs, and a power supply unit. Some computers use
small brackets to secure the subassemblies or pcbs
inside each chassis or assembly. Each chassis or
assembly is secured with retaining hardware. Check the
computer technical manual to see if you can leave the
power on while the assembly or chassis is extended or
is being extended; it varies with the computer. This will
affect the ability to extend subassemblies or pcbs on an
extender card with the power on.
Support functions, such as power supplies and
blower units, for chassis- or assembly-designed com-
puters are usually located on a fixed chassis or assembly
in the computers frame or cabinet. Chassis- or
assembly-designed computers can also be water cooled.
The functional areas that are basic to most chassis-
or assembly-designed computers include the following:
Central processing unit
or Rack-Designed Computer
Computers that use cages or racks contain the
Q A cage or rack
Figure 2-11.Example of a chassis- or assembly-designed computer.