laptops and portable devices

LAPTOPS AND PORTABLE DEVICES

• A TYPICAL PORTABLE COMPUTER HAS THE FOLLOWING COMPONENTS: • INTEGRATED LCD DISPLAY• INTEGRATED KEYBOARD WITH POINTING DEVICE• STANDARD I/O PORTS (USB, PS/2 MOUSE AND KEYBOARD; SOME MIGHT ALSO

INCLUDE SERIAL AND PARALLEL)• PC CARD (CARD BUS) OR EXPRESS CARD EXPANSION SLOT• INTEGRATED DRIVES• BATTERY

• Proprietary motherboard with integrated video or 3D graphics and mobile-optimized processor; some memory might be built into the motherboard

• Integrated speakers• Integrated wired (10/100 or gigabit ethernet) or wireless (wi-fi) network

adapters• Integrated analog (dial-up) modem • Some advanced portable computers also feature• Ieee-1394a ports• Flash memory card reader• Connector for docking station or port replicator

STORAGE DEVICES

• Laptop and portable computers use storage devices that vary in several ways from those found in desktop computers:

• Smaller form factors— laptop and portable systems use 2.5-inch or 1.8-inch hard disks, instead of the 3.5-inch hard disks found in desktop computers. Also, laptop and portable systems use slimline optical drives rather than the half-height drives that are used in desktop computers.

• Different implementations of common interfaces— although laptop and portables with sata drive support use the same power and data connectors as desktop systems with sata drives, pata (ata/ide) drives found in laptops and portable systems use a single 44-pin connector for both power and data.

• Systems that have no internal provision for the type of drive desired can attach an external drive to any of the following:

• USB 2.0 port• IEEE-1394a port• eSATA port• PC Card or Express Card with USB, IEEE-1394a, or eSATA port

PERIPHERALS• Low-end laptop and portable computers usually feature limited expandability;

if the device can’t connect to one of the ports built into the computer (or to a hub connected to the computer), you can’t use it.

• But high end laptops and portable computers feature various methods for connecting additional devices.

DOCKING STATIONSA docking station expands the capability of a portable computer by adding features such as

One or more expansion slotsAdditional I/O ports, such as serial, parallel, PC card or expresscard, VGA,

component video, SPDIF digital audio, or USB 2.0Additional drive baysConnectors for a standard keyboard and mouse

Most docking stations are produced by the vendor of the portable computer and connect to the computer through a proprietary expansion bus on the rear or bottom of the computer.

PORT REPLICATORS• A port replicator usually connects to the same proprietary expansion bus that

can be used by a docking station; however, many portable computers that do not have docking stations support optional port replicators.

• Port replicators don’t have expansion slots or drive bays but replicate the same ports that are found on the host pc. These ports might include VGA, Ethernet network, USB 2.0, and legacy ports (PS/2 mouse, keyboard; serial; parallel).

• Port replicators enable a portable computer user fast, easy connection to a full-sized keyboard, regular mouse or pointing device, desktop VGA monitor, modem, and printer without needing to attach or remove multiple cables.

• The difference between a port replicator and a docking station is that a docking station gives you the same ports on a computer but a docking station gives you extra ports and even features.

DOCKING STATION

PORT REPLICATOR

DUAL DISPLAYS

• THE DUAL-DISPLAY KEY IS USEFUL WHEN YOU HAVE A SECOND MONITOR CONNECTED TO THE LAPTOP OR WHEN THE LAPTOP IS CONNECTED TO A PROJECTOR DURING A PRESENTATION

POWER SOURCES• LAPTOPS AND PORTABLE COMPUTERS CAN USE BATTERY POWER OR

EXTERNAL DC POWER SOURCES, SUCH AS AC ADAPTERS, 12V CIGARETTE LIGHTER ADAPTERS, OR AIRLINE POWER CONNECTORS.

• BATTERY LIFE DEPENDS ON SEVERAL FACTORS, INCLUDING; BATTERY TYPE RECHARGING PRACTICES POWER-MANAGEMENT OPTIONS MEMORY SIZE CPU SPEED AND TYPE PC CARD OR EXPRESSCARD TYPE AND USE

BATTERY TYPES• THE RECHARGEABLE BATTERY TYPE USED BY A PORTABLE COMPUTER HAS A

GREAT DEAL TO DO WITH THE AMOUNT OF TIME YOU CAN USE A COMPUTER BETWEEN RECHARGES (THE RUN TIME).

• THE MOST COMMON BATTERY TYPES INCLUDE• LITHIUM-ION (LI-ION)• NICKEL-METAL HYDRIDE (NIMH)• NICKEL-CADMIUM (NICD)

• Nicd, has fallen out of favor for use as a notebook computer’s main power source because of a problem called the memory effect. If nicd batteries are not fully discharged before being recharged, the memory effect enables the battery to be recharged only to the level it was used.

• Low-cost notebook computers use nimh batteries instead of nicd. Nimh batteries have fewer problems with the memory effect and can be used in place of nicd in most cases.

• The most efficient battery technology in widespread use is li-ion, which has little problem with memory effect, puts out the same power as nimh, but is about 35% lighter.