CHAPTER 19 WORKING WITH A PORTABLE PC

	Introduction :
	You can use portable PCs while traveling, at home or any other place of choice. Portable PCs are highly used in fields such as education, science and business, among others.
19.1 Types of Portable PCs
	Portable PCs vary in size and features. One type of portable PC is the laptop that is comparable to a briefcase in size and structure. Notebooks and subnotebooks are smaller versions of laptops. The palmtop is small enough to be held in the palm of the hand.
	19.1.1 Laptops
	A laptop is a portable computer that can perform all of the tasks carried out by a desktop system. This type of computer is small enough to fit on the lap of a person, hence the name. You can use a laptop to create programs, multimedia applications, word documents, presentations, and spreadsheets. A laptop is like a briefcase in structure and you can carry it around wherever you go. A laptop appears.
	19.1.2 Notebooks
	A notebook is an extremely small and lightweight version of a portable computer. They can fit into a briefcase and be carried around. Currently, notebooks and laptops are virtually the same in most respects. Notebooks use flat panel technologies to produce a lightweight display screen. A notebook appears.
	19.1.3 Subnotebooks
	Subnotebooks are a smaller and lighter version of the notebook. They generally have smaller keyboards and screens as compared to notebooks. Subnotebooks usually have external drives and may have the serial and parallel ports on an external device. A subnotebook appears.
	19.1.4 Palmtops
	As the name suggests, palmtops are computers that you can carry around in the palm of your hand. These computers use a pen for input and not the keyboard. Most palmtops do not have disk drives because of their size limitations. Palmtops are also called Personal Digital Assistants (PDAs), handheld computers or pocket computers. A palmtop and the pen appear.
19.2 Features of Laptop
	The features of laptops vary based on the model of the laptop. Its features determine the usage and convenience of a laptop. The different characteristics of a laptop that determine its usage are: _ Weight - Is an important feature of the laptop, since its key function is to allow easy carriage and use. The weight of laptops range from 2 to 5 Kgs. A laptop must be light enough to carry around with ease. _ Size - Must fit into the user's bag or case with ease. A smaller laptop can be handled with ease. As a result, smaller laptops are considered more viable. _ Case material - Is a key feature of laptops. The case cover must be strong enough to withstand pressure in the case of a fall. You must find out the composite material of a laptop case cover. _ Cost - Differs widely based on the features of a particular model. Laptops are considerably costlier than desktop systems, due to their portability. _ Interface - Must be comfortable to the user. The screen display must be clear. The keyboard and other input devices must also be easy to use. The keyboard of a laptop is slightly different from that of desktop systems. Also, laptops are provided with input devices like a trackpoint or touchpad in order to move the cursor on the screen. These mechanisms can be used in place of the mouse.
19.3 Laptop Design
	The design of a laptop depends on the applications it will be used for. The design of a laptop is implemented based on various points. The most important point to be considered while designing a laptop is its portability. The design characteristics of a laptop are: _ Size and weight - Kept to a minimum to ensure ease of transportation. _ Screen size - Restricted between ranges of 12 inches to 17 inches. The screen is designed using Thin Film Transistor (TFT) display. TFT is a type of Liquid Crystal Display Technology that ensures superior screen display. _ Performance -Is a key point to be considered in the design of the laptop. The level of usage and performance expected from a particular model is very important to consider while designing it. _ Battery life - Must help in elevation of the life span of a battery. The laptop CPU is a key component that decides the lifetime of a battery. _ Onboard Components - Must be placed so as to limit the size of the laptop. However, the number of components in modern laptops is no longer limited. The components must be arranged in a manner that enables good connectivity between users. _ Ports and sockets - Enable connection to various devices. The different ports like firewall, USB and parallel port connect to different devices. The power socket, modem socket and network socket are some other important ports that must be considered while designing a laptop. The ports on the laptop must be designed to allow easy connection to devices like a phone or camera. These must also enable the user to have network access.
19.4 Laptop Components
	Laptops have different components like the motherboard, memory, ports and sockets that work together to provide the functionality of the laptop. You can connect different devices to the laptop with the help of the ports. The infrared ports on a laptop enable wireless connections.
	19.4.1 Motherboard
	The motherboard is the most important component of the laptop. It connects directly or indirectly to all the components of the laptop. Laptop motherboards have very advanced features.
	19.4.2 Memory
	Laptops have RAM and ROM, similar to ordinary desktop computers. However, the memory modules of laptops are different as compared to desktop computers. The laptops mostly use Small Outline Dual Inline Memory Module (SODIMM). These modules are small in size and have capacities between 16 MB to 1GB. Laptops generally have a minimum of 64 MB of RAM.
	19.4.3 Microprocessor
	The microprocessor is the central unit that co-ordinates all the functions of the laptop. It performs all the operations of the laptop, according to instructions from the operating system. Laptop microprocessors have additional features that enable reduction of power consumption. Laptop microprocessors also have multiple sleep modes. They operate at lower voltages. This increases the battery life. The features of a laptop microprocessor are : _ The microprocessor stores its instructions in the memory. It refers to the memory periodically when it is performing a task. _ It receives data input from the user though a mouse, keyboard, trackball, or touchpad. _ It sends data output to the user through the monitor. It also sends data output to other devices such as the printer or modem. It also enables data transfer though networks. _ The microprocessor receives data through different storage devices like CD/DVD drives, floppy drives, or hard drives. It can also store data in disks by using these devices.
	19.4.4 Hard Drives
	The Hard Drive is present internally in all laptops. This drive stores the operating system, applications and data. A laptop hard drive generally has a capacity between 6 and 80 GB. A laptop hard drive works in the same manner as a desktop hard drive. However, due to space limitations, the disk space is limited on laptop hard drives.
	19.4.5 Floppy Drives
	The Floppy Drive in the laptop enables storage of data to a floppy disk. You can also input data and store it on your laptop using a floppy disk. The floppy drive can be an internal part of the laptop. Some laptops have floppy drives connected externally by cables.
	19.4.6 CD and DVD Drives
	The CD and DVD drives on the laptop enable data transfer to CDs and DVDs. You can also store data on CDs and DVDs from the laptop. Some laptops have a single bay where you can interchange the drive inserted in the bay. Other laptops can have multiple bays for different drives. There are certain laptops that have no bay in the structure. Such laptops are designed this way to keep the size and weight of the laptop to a minimum. Figure 19.5 displays a CD drive on a laptop.
	19.4.7 Batteries
	All laptops have batteries as an alternate source of power. Laptops are portable because they are powered by batteries. The different types of batteries used by laptops include nickel-cadmium, lithium ion and nickel-metal hydride. Nickel cadmium batteries were in wide use previously. They offered good output at a low cost to the earlier laptop users. However, the lithium ion and nickelmetal hydride batteries are popular presently. Nickel-metal hydride batteries were introduced with several improvements over the nickel cadmium batteries. However, both nickel-cadmium and nickel-metal hydride batteries have a drawback called the memory effect. Memory effect is the reduction of power storing capability of a battery, which occurs when the battery is recharged before it is fully discharged. The lithium ion batteries offer improvements in capacity and reduction of memory effect. The lithium ion batteries are therefore the most popular version of laptop batteries presently. Batteries have different life spans depending on the amount of usage and the type of battery. Laptops have inbuilt power management software that helps to extend the lifetime of the battery. When the battery is low, the power management software makes the laptop function slowly. This acts as a signal to the user to recharge the battery or connect the laptop to the power supply socket.
	19.4.8 Device card (PCMCIA card)
	The PCMCIA card is a memory or I/O device that is about the size of a credit card. The PCMCIA card connects to the laptop. The card then connects to a device such as a fax, modem or memory device. PCMCIA stands for Personal Computer Memory Card International Association, which is a foundation that developed a standard for device cards. As a result, laptop users can be assured of a standard attachment for all devices that follow the PCMICIA standard. The PCMCIA card has a 68-pin connector that connects to a slot on a laptop. The different types of PCMCIA cards are: _ Type I - Used mostly for connecting to memory devices. These cards are about 3.3 mm. thick. _ Type II - Typically connects to a modem, a SCSI device or a sound device. These cards are about 5.5 mm. thick. _ Type III - Used to connect to hard drives. These cards are about 10.5 mm. thick. The different types of cards have slots of corresponding sizes. The Type I slot can accommodate only one Type I card. The Type II slot can hold a single Type I or Type II card. The Type III slot can accommodate a single Type III card. It is possible to simultaneously connect any combination of two Type I and Type II cards in a Type III slot.
	19.4.9 Infrared ports
	The infrared ports on laptops enable the laptop to communicate with other devices without using cables or wires. Thus, the infrared ports enable wireless communication between laptops and other devices. The infrared ports communicate and transmit data using infrared light waves. This is somewhat similar to the way a TV remote communicates with the TV. The device that the infrared port communicates with must have a corresponding infrared port. If you have a printer that has an infrared port, it can communicate with your laptop without cables. You can print documents by placing the printer and laptop opposite each other, with their infrared ports facing each other. However, the two communicating devices must be within a few feet of each other and the path between them must be clear of any intrusions. Figure 19.6 displays the PCMCIA port and infrared LAN port on a laptop. PCMCIA Port Infrared LAN Port
	19.4.10 I/O Ports
	The laptop connects and communicates with other devices with the help of the I/O ports. The different I/O ports on a laptop are: _ Power socket - Connects to the AC adapter card, which connects to the power socket. _ Modem socket - Connects to the modem for making dial-up connections to the network. _ Network socket - Connects to the network cable. _ Microphone socket - Connects to a microphone for audio input. _ Headphone socket - Connects to the headphone for audio output. _ Parallel port - Used to connect to devices such as printers or scanners. _ Serial port - Connects to devices such as modems and mice. _ USB ports - Connect to devices such as floppy drives or CD-ROM drives. _ S Video port - Enables output of video to the monitor or another screen. _ Monitor port - Connects to the monitor of the laptop. _ Firewire port - Enables connections to different devices. Figure 19.7 displays the different ports on the back of a laptop. Figure 19.7 - Ports on a Laptop 19.4.11 A/C Adapters The AC adapter supplies power to the laptop. The AC power from the power socket is converted into DC power, which can be used by the laptop. Figure 19.8 - AC Adapter Monitor Power S Video Parallel Network Modem USB Headphone Microphone
19.5 Laptop Input and Output Devices
	The different input and output devices of the laptop enable users to store data in the laptop and also to access and retrieve information. The keyboard, display, and pointer devices are the main input and output means of a laptop.
	19.5.1 Keyboard
	The keyboards of laptops are generally small in size and mostly have additional features that enhance user comfort. Laptops generally do not use ergonomic keyboards. The locations of the keys will also be different as compared to a desktop keyboard. All laptop keyboards will not have the numeric keypad.
	19.5.2 Touch Pad
	Touch pads are very common input devices for laptops. These devices are a little larger than credit cards. A touch pad responds to movements of the hand on its surface. You can drag your fingers and tap them on the touch pad to move the cursor on the screen. Touch pads are very easy to use and are highly accurate.
	19.5.3 Trackpoint
	The trackpoint is a small button located between the keys on the laptop keyboard. You can move the cursor on the screen by pushing the point around with your fingers.
	19.5.4 Display Screen
	The display screens on all laptops use Liquid Crystal Display (LCD) technology. Laptop displays are generally between 12 to 17 inches in dimension. The display can be grayscale or color. Laptop displays generally have resolutions of 640 x 480 pixels and higher.
19.6 Troubleshooting
	You can come across many problems on your laptop, the cause of which can be software or hardware. You must systematically follow troubleshooting steps to detect the cause of the problem and repair it.
	Best practice
	1. Check all cable connections. 2. Verify whether the power is turned on. 3. Do not use the laptop in a hot environment. 4. Always store data backups in floppy disks or CDs. 5. Handle the laptop gently and with a lot of care. 6. If you are traveling, ensure that the laptop battery is not empty.
	Precautions
	1. Turn off the laptop and disconnect it before performing any troubleshooting. 2. Wear an anti-static wristband.
	19.6.1 Laptop does not start after being turned on
	Sometimes the laptop will not start working after being turned on. This is most probably a power supply problem. It can also be a result of overheating. 1. If you are using a battery, inspect it to verify whether it needs recharging. If it does, recharge the battery after fully discharging it first. 2. Check the connection of the power cable to the socket. The connection must be tight. 3. Check the AC adapter. If the light on the AC adapter is not on, it is not working properly and must be replaced. 4. If the power indicator shows a blinking orange light, the laptop has probably shut down because of overheating. 5. Check the output vent of the laptop to see if the fan is working. 6. See if there is any dust covering the output vent. 7. Clean the dust carefully with a soft dry cloth. 8. Allow the laptop to cool down and then restart it. _ You can find out if your battery needs a recharge or replacement by turning off the AC power. If the laptop shuts down totally, the battery needs recharging. If your battery remains cool to the touch after an hour or more of recharging, it will have to be replaced.
	19.6.2 Ctrl+Alt+Delete does not Work
	Sometimes the Ctrl+Alt+Delete command does not work. If your laptop doesn't restart after you press these keys twice, there is a problem with your system. 1. Press the power button and turn off the laptop. 2. Restart the laptop and check the keyboard lights to see if the keyboard is recognized. Press the Num Lock or Caps Lock key to verify this. 3. If the keyboard is being recognized, contact the manufacturer. 4. If the keyboard is not recognized, connect another compatible keyboard to the laptop. If the laptop does not recognize the keyboard device, contact the manufacturer. 5. Check Event Viewer details to see if an error has been logged. 6. Run the Antivirus Program to detect a virus or Trojan horse in the system
	19.6.3 Printer does not work
	Printers are very important output devices. If the printer does not function properly, it could be the result of a hardware or configuration problem. 1. Check the printer light to see if it is on. 2. Check the cable connections on the printer as well as on the laptop. The connections must be secure. 3. If the printer is infrared, ensure that there are no obstacles between the infrared ports. 4. If the printer is blinking, refer to the manual to find out the cause of the problem. 5. Replace the printer with another compatible one. If this printer works, the laptop does not have any problem. 6. Ensure that the printer is set to Default Printer. 7. Go to Device Manager and check whether the printer driver is installed properly. 8. Press Delete when the laptop is starting up. This will take you to the CMOS setup. Check whether the printer port is enabled and working properly. 9. Ensure that the printer mode is not set to ECP. This mode can make the printer malfunction. 10. Run the printer self-test. If it fails, the printer is faulty and not the laptop.
	19.6.4 Laptop Keyboard gets Wet
	You must be very careful not to let any liquid spill onto the laptop keyboard. If the keyboard gets wet, it could cause serious damage to the keyboard as well as the laptop. 1. Shut down the laptop and remove the battery. 2. Unplug the keyboard and remove it. 3. Let all the liquid drain out of the keyboard. 4. Clean the keyboard with cotton swabs. 5. Clean the underside of the keys with an air blower/vacuum cleaner. Be careful to hold the nozzle at a proper angle. 6. Turn the laptop upside down very carefully, without damaging the display. Leave the laptop in this position for at least 48 hours before turning it on. 7. Plug in the keyboard and check if it is working. 8. If the keyboard does not work, it will have to be replaced.
	19.6.5 CD/DVD Drive problem
	Sometimes you may get a message like drive is not accessible or device is not ready, when you try to access your CD or DVD drive. This may occur even if the Device Manager does not show any fault. 1. Ensure that the connection to the drive is secure and the disk is properly inserted in the drive. 2. Check the surface of the disk for dirt or abrasions. 3. Clean the drive with a cleaning disk. 4. Try playing other disks in the drive. If no disk plays, there is a problem with the drive. 5. Try to access the drive after restarting the laptop.