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A+ Study Guide: Domain 2.0: Laptops and Portable Devices - Laptop Hardware


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Contents:
Introduction
Power
Processors
Memory
Hard Drives
Modular Drives
Displays
Docking Stations and Port Replicators
PCMCIA
ExpressCard
Mini PCI
Laptop Control Devices
Function Keys

Introduction:
This is the first tutorial in our Laptop and Portable devices guide. There are many different terms used for these devices including portable computers, notebooks, and laptops. In this guide, we are going to call them laptops. This particular section of the guide will discuss laptop hardware and accessories.

Power:
Laptops can run on AC power or on rechargeable batteries. There are 3 types of batteries that are used in laptops as follows:
  • Nickel-Cadmium (Ni-Cd) - This is an older technology that had a few problems. First, the batteries needed to be completely discharged before recharging or they wouldn't hold a very good charge. This was known as battery memory and resulted in comparatively short lifespans. They also had problems when overcharged. These batteries are extremely toxic and MUST be recyled.
  • Nickel-Metal Hydride (Ni-MH) - Still commonly used today, these do not have the charging problems that the Ni-Cd types did. They are much less toxic, but should still be recycled.
  • Lithium-Ion (Li-Ion) - These are the most commonly used batteries used today. They can hold a charge much longer than their predecessors, although cannot be recharged as many times. If a lithium-ion battery is overcharged, it can explode which is why devices that use these batteries have a built-in mechanism to prevent overcharging.
Fuel cell batteries are being developed now, but this technology is still very new and probably won't be on the A+ exams.

Although power management is used with desktops, it is of much greater concern with laptops. Today, we use specifications known as Advanced Power Management/Advanced Configuration and Power Interface or APM/ACPI to manage computer power. Devices that work with these specifications are known as Energy Star compliant which means that they use less power and allow APM/ACPI to shut them off when not being used. In addition to compatible devices, modern power management requires a compliant BIOS and operating system. All BIOSes offer APM/ACPI and newer Windows operating systems support APM/ACPI.

APM/ACPI is either configured through the BIOS or the operating system, however, the settings in the OS will override the BIOS settings. To access the power management features in Windows, open the Power Options control panel applet. Note that some laptops come with their own proprietary power management applications that may look different and have different features than what you see below.


This allows you to select from a variety of preconfigured power schemes (such as Portable/Laptop) or you can manually configure the settings for hard drives, monitors, etc. There are a couple of different power states that can configured in the Power Options control panel or they can be activated manually. These states are described below:
  • Stand by - Stand by, also sometimes called is a light sleep mode you can put your computer in. When you resume from Standby mode, you'll be exactly where you left off with all of your applications and documents still active on the screen. While in this mode, the hard drive usually stops running, the display turns off, and the fans might even turn off, but the computer still needs to be connected to a power source (battery or AC) or you will lose your work. On many laptops closing the lid or pressing the power button puts the laptop into standby mode. Another manual method is to click the Start Button and select Shut Down. After the Shut Down Windows screen appears, select Stand by (See image below).
  • Hibernate - Hibernation mode is the same as stand by, however, the hibernate mode allows you to turn off the computer completely and even unplug it from power. It takes longer to resume from a hibernated state. You can manually put your computer into hibernation mode by selecting Hibernate from the Shut Down Windows screen mentioned above.

Processors:
Both Intel and AMD make processors for laptops. These special CPUs are smaller, use less heat, and less power. On some laptops, these processors are upgradable, however, there are a couple of things to beware of:
  • Heat - Laptops are sensitive to heat and difficult to cool. A perfect example of this is my Toshiba Satellite which runs too hot for the design. It has to have the back propped up on a book to get more airflow underneath or else it overheats and shuts off. If you replace your CPU with one that runs too hot for the design of your system, you will likely run into overheating problems.
  • Installation - Installation of a laptop CPU may basically require you to tear the entire thing apart and put it back together. This depends on the particular make and model, but you should check out the procedure before deciding to upgrade.
Memory:
The majority of laptops have upgradeable RAM slots and most current laptops use 200-pin DDR/DDR2 SO-DIMMS, although some use 172-pin micro-DIMMS. Older laptops used 72 or 144-pin SDRAM SO-DIMMS. Some older laptops used proprietary RAM that had to be purchased at high prices from the laptop manufacturer.

Some laptops use a system called Shared Memory whereby the manufacturer includes less RAM on the video card which in turn helps itself to the system memory. The reason for doing this is that it make the video component much less expensive, however, the obvious side-effect is that the system will often have less than its full amount of RAM available when the video is using it.

Installing RAM on a laptop varies widely by manufacturer. The location of the RAM will vary widely, but in most cases there is a panel on the underside of the laptop that must be unscrewed.

For obvious space saving reasons, laptop RAM isn't vertically oriented as in a desktop computer and lays down flat. To remove the RAM, there will be some sort of lever or other restraining mechanism. In the image below, this laptop has a metal restraining metal piece which the white arrows are pointing to.


If we push these metal pieces outward, the RAM pops up at a 45 degree angle as shown below.


At this point, you can simply pull the RAM out and insert a new one. After inserting the new one, press down lightly and the metal clamps should automatically lock in. Again, the locking mechanism can vary by manufacturer, but most are similar to this.

Hard Drives:
There isn't too much to talk about regarding laptop hard drives. They are the same as desktop hard drives, only they are smaller and have smaller storage capacities for the most part. Desktop hard drives are 3.5 inch and laptop hard drives are 2.5 inch.

To remove or install a hard drive, there is usually a panel on the underside of the computer just as there is for memory. Unscrew the panel and insert or remove the hard drive.

Modular Drives:
One of the coolest features of laptops is the ability to configure drives the way you want. Most laptops have drive bays (also known as media bays or accessory bays) that can be ejected and replaced with a different component. For example, my laptop currently has the battery stored in the first drive bay and a CD/DVD-ROM drive in the other. Each of these drives has a lock and a release button on the bottom of the laptop. When unlocked and the button is pushed, the drive or battery can be pulled out and replaced with something else.


This particular laptop doesn't have the most convenient method for swapping out drives - others have systems that don't require you to flip the computer upside-down.

Let's say that I won't be needing my CD/DVD-ROM while I travel. I can replace it with a spare battery and get longer life between charges. Or let's say I worked for a company that still uses a lot of floppy disks. Most newer laptops no longer have floppy drives, but you can buy a modular one and swap it out when you need it. The best part is that on most laptops, these drives are hot-swappable meaning you don't have to turn off the computer to switch components. Some laptops suggest that you use Window's "Safely Remove Hardware" feature if swapping drives with the power on. The icon for this tool is in the system tray.

Displays:
Laptops use built-in LCD screens which are typically between 12 and 17 inches, although there are larger ones available including widescreen formats (see the Toshiba Satellite picture at the top of this article for an example of this). Most laptops have the capability to connect a larger CRT or LCD monitor as well.

Laptop LCDs can be classified by whether or not they use Thin Film Resistors (TFT, AKA Active Matrix) or are Passive Matrix. The older passive matrix LCD screens uses a grid of wires to produce the image on the screen. Dual-scan passive matrix improved refresh performance, but has been replaced with TFT technology which uses a transistor for each individual pixel instead of wires for the rows and columns.

Below is a table of the various laptop display standards in use with their aspect ratio and resolution. If you need more background on video, read the Multimedia tutorial located in Domain 1.0 of this guide.

Standard Aspect Ratio Resolution
XGA 4:3 1024x768
SXGA 5:4 1280x1024
SXGA+ 5:4 1400x1050
UXGA 16:10 1600x1200
WSXGA+ 16:10 1680x1050
WUXGA 16:10 1920x1200

LCD screens come in Matte Finish and High Gloss finish varieties. High gloss versions are newer and provide better contrast and brighter colors, but have more reflection.

Docking Stations and Port Replicators:
This is a somewhat confusing topic as many people use these terms interchangeably, but there are subtle differences. The purpose of both of these devices is to add desktop functionality to a laptop. Let's take a look at the differences.

A docking station contains a mixture of ports, slots, drive bays and security features. It usually attaches to the notebook from underneath with a proprietary connection. Docking stations come in a variety of shapes, ranging from the same size as your notebook to much bigger. As the name implies, a docking station is where you park your notebook when you are at the office, or wherever it is you keep your docking station.

A port replicator, on the other hand, is a smaller, stripped down version of a docking station that mainly features the ports that you would find on a typical desktop PC, but lacks drive bays and slots. Port replicators typically connect via a USB connection.

These devices are only commonly needed in a couple of different situations. The first is if you have a legacy peripherals that your laptop doesn't have ports for such as a parallel port. The other situation might be if you have an ultralight laptop that lacks the ports or drives included on larger laptops. With most laptops, modular drive bays, PCMCIA slots, and USB ports make it possible to connect or add just about any device needed without a docking station or port replicator.

PCMCIA:
The PCMCIA bus was developed for smaller computing devices and is hot-swappable. PCMCIA cards, now referred to as PC Cards (although CompTIA still uses the term PCMCIA), are very thin and provide connectivity for everything from removable media to ethernet connections. There are 2 types of PC Cards - 16-bit and 32-bit. Let's take a look at each of these:
  • 16-bit - This obselete version of PC Card only supported 2 functions per card (i.e. modem and ethernet connection) at a throughput of 160 Mbps. These cards can be used in 32-bit slots.
  • 32-bit - Also known as CardBus, this type comprises almost all of the PC Card slots you will come across. These cards support up to 8 functions on one card and provide a throughput of 1056 Mbps. 32-bit do not work in 16-bit slots.
Both of these PC Card types have 3 sub types as follows:
  • Type I - 3.3mm thick and used as memory expansion units.
  • Type II - 5mm thick and supports most expansion functions except removable hard drives. Type I cards will work in them.
  • Type III - 10.5mm thick and used mainly for removable drives. Type I and II cards will work in them.
ExpressCard:
On newer laptops, the PC Card standard is being replaced by a serial version called ExpressCard. These cards are smaller and are not backward compatible with PC Cards. ExpressCards use either the USB bus at speeds up to 480 Mbps or the PCIe bus at speeds up to 2.5 Gbps. They come in 34mm or 54mm width sizes with the 54mm versions missing a corner (see picture above). The thickness is 5mm (same as a type II CardBus card).

Mini PCI:
Mini PCI is a version of the PCI bus for laptops. Although most laptops come with most ports needed and their functionality can be expanded using PC Card and ExpressCard devices, there are some occasions when you might want to upgrade a component in a laptop. For example, when the next generation of wi-fi becomes standard, it will likely provide better security and speed. To take advantage of this, you may want to swap out the wi-fi PCI card in the laptop. The image to the right shows a mini PCI wi-fi adapter.


Laptop Control Devices:
On a desktop PC, we use a mouse and keyboard to input our wishes into the computer. On a laptop, the keyboard is built in and you can certainly attach an external mouse. But laptops come with built-in mouse-like devices. There are 2 basic types commonly used today as follows:

The older of the 2 types is called TrackPoint and was invented by IBM. TrackPoint uses a small pencil eraser sized "nub" to move the computer cursor around. This "nub" is usually located in the middle of the keyboard (blue dot in right image) and acts much like a joystick does. The functionality of a mouse's left and right click buttons are provided by 2 buttons below the space bar.

The second type is called a touchpad. Touchpads provide a small touch-sensitive pad located just below the spacebar on the keyboard. Moving your finger across the touchpad moves the cursor on the screen. Below the touchpad are the 2 buttons that act like a mouse's left and right click buttons. Touchpads are typically provided on larger sized laptops that have room to include them. Some laptops provide a TrackPoint device as well as a touchpad.

Function Keys:
Laptops come with a special function key (Fn) that is located where the Windows key is located on desktop keyboards. The Fn key is pressed in combination with one of the F1-F12 function keys to perform various tasks such as adjusting the screen brightness, disabling wi-fi, and other tasks. These tasks vary by manufacturer. Here are a couple of examples from a Toshiba laptop.


Fn + F2 displays the power level of the batteries.


Fn + F5 allows us to select the video output device.





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