Datasheet

64 Chapter 1
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Hardware
Principles of Laptops and
Portable Devices
Whether you choose to call them laptops, portable devices, or something different is mostly
a matter of semantics. This objective tests your knowledge of some of the basic operations
of laptops. In many cases, the components are the same as in a desktop computer, and they
were discussed already. We’ll focus now on those that are different.
Critical Information
A portable computer must provide all the functionality of a desktop counterpart yet be able
to withstand travel, run in the absence of AC power, and be much smaller and more com-
pact. When you get right down to it, there is not a great deal of difference between laptop
and desktop computers, with the exception that laptops are more difficult to disassemble
and form factors on items such as motherboards, memory, and hard drives become impor-
tant. While they perform the same functions, size is critical.
Laptop-specific elements are discussed in this section.
Docking Stations
Some notebook PCs have optional accessories called docking stations or port replicators.
These let you quickly connect/disconnect with external peripherals and may also provide
extra ports that the notebook PC doesn’t normally have.
A docking station essentially allows a laptop computer to be converted to a desktop
computer. When plugged into a docking station, the laptop has access to things it doesn’t
have as a stand-alone—the network, a workgroup printer, and so on. The cheapest form
of docking station (if it can be called that) is a port replicator. Typically, you slide a laptop
into the port replicator, and the laptop can then use a full-sized monitor, keyboard (versus
the standard 84 keys on a laptop), mouse, and so on. Extended, or enhanced, replicators
add other ports not found on the laptop, such as PC slots, sound, and more. The most com-
mon division between port replicators and docking stations is whether the peripheral pro-
vides network access and expands the laptop’s capabilities.
Laptops can support Plug and Play at three different levels, depending on how dynami-
cally they’re able to adapt to changes:
Cold Docking The laptop must be turned off and back on for the change to be recognized.
Warm Docking The laptop must be put in and out of suspended mode for the change to
be recognized.
Hot Docking The change can be made and is recognized while running normal operations.
Each docking station works a little differently, but there is usually a button you can
press to undock the notebook from the unit. There may also be a manual release lever in
case you need to undock when the button is unresponsive.
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