Hardware Reference
In-Depth Information
Figure 4.7. LPX motherboard back panel connectors.
The connectors along the rear of the board would interfere with locating bus slots directly on the
motherboard, which accounts for why riser cards are used for adding expansion boards.
NLX
NLX is a low-profile form factor designed to replace the nonstandard LPX design used in previous
low-profile systems. Introduced in November 1996 by Intel, NLX was a popular form factor in the
late 1990s for Slimline corporate desktop systems from vendors such as Compaq, HP, and Toshiba.
Since 2000, many Slimline systems have used variations on the FlexATX motherboard instead.
NLX is similar in initial appearance to LPX, but with numerous improvements designed to enable full
integration of the latest technologies. NLX is basically an improved version of the proprietary LPX
design, but, unlike LPX, NLX is fully standardized, which means you should be able to replace one
NLX board with another from a different manufacturer—something that was not possible with LPX.
The main characteristic of an NLX system is that the motherboard plugs into the riser, unlike LPX
where the riser plugs into the motherboard. Therefore, the motherboard can be removed from the
system without disturbing the riser or any of the expansion cards plugged into it. In addition, the
motherboard in a typical NLX system literally has no internal cables or connectors attached to it! All
devices that normally plug into the motherboard—such as drive cables, the power supply, the front
panel light, switch connectors, and so on—plug into the riser instead (see
Figure 4.8
)
. By using the
riser card as a connector concentration point, you can remove the lid on an NLX system and literally
slide the motherboard out the left side of the system without unplugging a single cable or connector on
