Chapter 15: The System Case^359
I/O Templates
Each motherboard form factor also defines the location and placement of the ports used
for such input/output devices as the keyboard, mouse, printer, and others. For the most
part, these ports are connected either directly or indirectly to the motherboard. Directly
connected ports are physically mounted on the motherboard. The case must accommo-
date these ports with a hole in the right shape so the PC user can access the port. Indi-
rectly connected ports usually mount to the case and are attached to the motherboard
with a cable; the case has to either be manufactured with the portholes already in place or
provide an adapter for this purpose.
Older form factor cases, such as the PC XT, AT, Baby AT, and the LPX, were manufac-
tured with holes cut into the rear panel of the case to match a particular form factor. How-
ever, to make cases more flexible and allow them to service more than a single form
factor, manufacturers devised I/O templates, which can be snapped into a case to pro-
vide the I/O port pattern desired. Figure 15-16 shows where on the case an I/O template
is located; Figure 15-17 shows what the templates look like out of the box.Figure 15-15. In-Win’s FlexATX case. Photo courtesy of In-Win Development, Inc.