Introduction to PDA's
A PDA (Personal Digital Assistant, also called a pocket organizer) is a pocket computer composed of a processor, RAM (Random Access Memory), a touch sensitive screen, and network functions bundled in an extremely small compact case.
PDA Use
A PDA is a pocket computer originally designed as an organizer. A personal assistant generally supplies the following standard applications:
an agenda to organize time, with visual or mechanical reminders. Meetings or planned events can be contextualized in order to meet professional and personal requirements thanks to an adaptable classification system (office, private, etc.).
a task manager that serves as a reminder for tasks to be done. The priority, deadlines or reminders can be assigned to each task.
an address book (contact manager) that provides instant contact information (phone number, mailing address, email, etc.).
email software that allows messages to be received and sent.
Personal assistants offer light versions of office automation tools such as text editors, spreadsheets, a calculator, and viewers for a wide variety of file formats (PDF files, images, etc).
In addition to these basic functions, more and more PDA’s offer advanced multimedia tools for playing videos (in different formats, including DivX format), music (notably in mp3 format) and Flash animation.
PDA’s are also used with increasing frequency for geo-referencing, mapping and road navigation by plugging them into a geo-reference device (GPS, Global Positioning System). In effect, it is possible to obtain a compatible, low cost and high performance GPS that helps with road navigation a using a map that continually displays the user’s location, speed and a visual representation of the road (eventually in 3D) with instructions both on-screen and from a synthesized voice.
Operating System
PDA’s have operating systems adapted to their screen resolution and whose features correspond to the characteristics of the device.
Many types of operating systems exist for PDA’s, usually different for each type of PDA and each manufacturer, the same as there are Mac and PC computers. The two main operating systems are:
PalmOS, marketed by Palm.
Windows Mobile or Pocket PC (formerly Windows CE), marketed by Microsoft.
These two systems have almost the same characteristics and the same functions, but with different methods of holding them and with incompatibilities between systems.
Note that there are Linux operating systems that were specifically developed for both types of machines.
Technical Characteristics
When purchasing a PDA, it is important to pay attention to the following characteristics:
weight and size: PDA’s are designed to be carried everywhere and must therefore fit into hands and pockets. Its size and weight must be as small as possible, bearing in mind ergonomic requirements and screen size.
autonomy: A PDA’s autonomy is a function of its battery’s characteristics.
Ni-Cad (Nickel / Cadmium): a type rechargeable battery now obsolete due to its memory effect, meaning a progressive reduction of the maximum charge when it is recharged before being completely "empty".
Ni-Mh (Nickel / Metal Hybrid): a type of rechargeable battery with higher performance than nickel-cadmium batteries.
Li-Ion (Lithium / Ion): a type of rechargeable battery that is found in most computers. Li-Ion batteries give excellent performance for a moderate cost. As well, Li-Ion batteries do not suffer from memory effects, which means that they can be recharged before becoming completely empty.
Li-Polymer (Lithium / Polymer): a type of rechargeable battery with performance similar to that of Li-Ion batteries, but made much lighter by replacing the electrolyte fluid and the micro-porous separator of Li-Ion batteries with a much lighter solid polymer. However, the recharging time is longer and their life expectancy is shorter.
Be careful about data loss when the battery is totally empty!
Sunday, August 17, 2008
Laptop Computer
Relegated several years ago only to business use, laptop computers now have processing and storage capabilities close to that of desktop computers, and can easily be used for high-tech multimedia purposes (DVD drive, video games, 3D-image processing, etc.). If the price of a laptop computer is still higher than that of a desktop computer because of its mobility, its use is also more varied because of the fact that can be taken virtually anywhere.
However, given its reduced size, most of a laptop computer's pieces are integrated and therefore cannot be changed. This is why users must choose their laptop's characteristics once they are well-informed and have their planned use in mind. On the other hand, the fact that the manufacturer integrates the components allows for reduced risk of hardware incompatibilities (hardware conflicts).
What is a Laptop Computer?
A laptop computer (also called notebook computer) is a computer that integrates all the elements that needs to run properly, including a battery power supply, a screen and a keyboard, in a small casing (on average 360 cm x 40 cm x 270 cm).
Why a Laptop?
The main advantage of a laptop computer versus a desktop computer is its mobility as well as its reduced size. On the other hand, the price is generally higher for slightly less impressive performance and the laptop's hardware configuration is much less adaptable, even though it is possible to connect additional external peripherals thanks to its numerous I/O ports. Therefore, the motivation for buying a laptop computer must above all be a need for mobility or a need to save space.
Moreover, with the emergence of wireless networks, and WiFi in particular, it is becoming very easy to connect to the Internet in public Hot-Spots or simply in any room of your home as long as it is equipped with a WiFi terminal.
For advanced multimedia uses (e.g. digital video manipulation, connecting a digital camera or an mp3 player, etc.), the choice should fall on both the computer's performance (both graphic as well as computing power) and on the types and number of I/O ports that are available.
Processor and RAM
The processor represents the computer's brain in that it processes the instructions. Its execution speed depends on its frequency (in MHz), but two processors from different brands that have very different frequencies can perform equally.
Even though a processor's frequency is still an essential criterion for choosing a laptop computer, today it is preferable to favour the quality of all the components (graphics card, memory, etc.) over only the processor's frequency.
What is more, the quantity of random access memory (RAM) can have a considerable effect on performance, notably when it comes to multimedia use. In addition to the quantity of memory, it is also important to pay attention to its working frequency, which corresponds to the frequency that most of the peripherals will run on.
Screen
Laptop computers have flat screens. Most of the time they are active matrix screens (generally with the TFT, Thin Film transistor technology), i.e. each pixel is individually controlled, allowing for improved display fluidity over passive matrix screens, on which pixels are controlled by line and by column. The latest generations of laptops have favoured active matrix screens over passive matrix screens.
The screen is distinguished first of all by its size, which is expressed in inches (an inch equals 2.54 cm) and corresponds to the screen's diagonal length. Unlike screens with cathode ray tubes (CRT screens), the diagonal length of a flat screen corresponds to the effective display area. Moreover, considering the liquid crystal based technologies used in flat screens, the screen quality of a flat screen can be defined by the response time, which is the length of time necessary to turn a pixel from white to black and then back to white.
The display format is generally 4:3 (i.e. 4 units wide to 3 units high), but there are more exotic laptop display formats that are close to 16:9, such as 15:10, which is adapted to viewing video sequences (e.g. watching DVDs). In general, this type of screen has does not have a whole number diagonal length (e.g. 15.4 inches).
Hard Drive
The hard drive is the area where all the computer's data is stored unlike the RAM, which is a volatile memory that only acts as an information transit area while the computer is running. The most important characteristic of the hard drive is its capacity (expressed in gigabytes), because it determines the amount of data (and, in particular, programs) that a user can store on it. However, it is a good idea to pay particular attention to its performances (in relation notably to its spindle speed), which can hamper the system's overall capacities if they are too weak.
Using external hard drives (FireWire or USB 2.0) can nevertheless enhance a laptop computer by wiping out the intrinsic limitations of its standard hard drives and extending its storage capacity ad infinitum.
Graphics Card
A laptop computer's graphics card is integrated, i.e. it is a specialised graphics chip (graphic chipset) that is soldered to the motherboard. It is impossible to change it once the laptop has been purchased. Therefore, if the laptop computer will be used for graphics applications (video visualisation or manipulation, video games, 3D applications, etc.), it is best to choose a top-of-the-line graphics chipset.
CD/DVD Drive or Burner
More and more laptop computers are making a CD-ROM or a DVD-ROM drive or even a burner into standard features on high-level configurations. When the drive combines several of these functions, it is called a "combo".
There are different types of CD (with a capacity of about 700 Mb) and DVD (with a capacity of about 4.7 Gb) burners.
The term "CD-R" refers to recordable compact disks
The term "CD-RW" refers to rewritable compact disks
The term "DVD-R" refers to recordable DVDs
The term "DVD-RAM" refers to rewritable DVDs Thus, there are two incompatible standards promoted by different manufacturer consortiums:
DVD+RW, by Philips, that have performances in terms of recording time that are generally slightly better than the DVD-RW format
DVD-RW, which cost slightly less than DVD+RWs
It should be noted that some burners support both of these standards and thus are called "multi-format" burners.
Input/Output Interfaces
Input/output interfaces allow you to extend a laptop computer's functionalities by connecting external peripherals. Laptops generally have PC Card connectors (PCMCIA) that allow you to insert additional peripherals.
USB ports are available on all recent laptop computers but it is a good idea to verify if they are USB 1.0 ports, which offer a peak throughput of 12 Mbit/s, or USB 2.0 ports, which can have a peak throughput of up to 480 Mbit/s!
Having IEEE 1394 ports (with the commercial name of FireWire on Apple machines and i.LINK on IBM compatible machines) is a good idea for those users acquiring video from a DV digital video camera. FireWire ports allow throughputs on the order of 800 Mbit/s!
Some laptops come standard with multi-card readers that can read flash memories in the following different formats: Secure digital (SD Card), Multimedia Card (MMC), Memory stick (MS), SmartMedia (SM), Compact Flash (CF) or xD picture card. This type of reader can be extremely practical for those people who have MP3 players, digital cameras or personal desktop assistants (PDAs) because it facilitates the direct copying of files (e.g. music or digital photos) at a high bandwidth.
Audio and Video Input/Output
Every laptop computer has a screen and internal speakers but in some circumstances it is useful or even necessary to connect it to higher performance stereo or video systems (e.g. for a presentation or for a DVD projection).
Laptop computers come standard with a VGA connector, which allows you to connect them to an external monitor or a video projector. Sometimes laptops come equipped with a video output (called a TV output), i.e. a S-Video connector that allows you to connect the computer directly to a television.
With regard to audio I/O, all laptop computers come with standard headphone and microphone jacks as well as stereo speakers of varying quality. Having a S/PDIF output (digital audio output) can allow users to connect their laptop to a sound system that supports Dolby Digital 5.1 (e.g. for Home Cinema use).
Pointing Device / Keyboard
Laptop computers come standard with an integrated keyboard and pointing device. The pointing device is generally a touchpad, i.e. a flat touch-sensitive surface that allows you to move the cursor like a mouse. Some laptops come equipped with a trackpoint, i.e. a little touch-sensitive eraser-like tip (generally red) located in the middle of the keyboard that allows users to move the cursor with their fingers.
The keyboard and pointing device should be chosen according to their ergonomics. They should be tried out in order to determine if they are comfortable to use.
It should be noted that nothing prevents users from connecting a traditional mouse to a laptop computer for more comfort.
Mobility and Network Connectivity
In the communications world that we live in today, it is impossible to imagine a laptop computer without network functionalities. The terms nomadism and mobility are used to refer to individuals' capacity to have access to their information over the Internet, no matter where they are.
Most laptop computers come standard equipped with a 56K V90 modem that allows them to connect to the Internet over the telephone network (STN, switched telephone network).
The "10/100 Mbit Fast Ethernet" connector can be used to connect a laptop to a local area network (LAN) or to connect it to network equipment such as an ADSL modem, a router, a switch or even directly to another computer with a crossover network cable.
With the emergence of wireless networks and the increased number of public and private wireless network access points (called hot spots), the concept of nomadism is taking on a whole new meaning. Thus, some laptop computers now come standard with built-in or card WiFi adapters. WiFi technology allows computers equipped with specialised adapters (WiFi cards) to connect with each other over a range of several dozen or even hundreds of meters and possibly even to connect to the Internet thanks to a wireless router (WiFi terminal). There are several WiFi standards that use different transmission channels:
WiFi 802.11a for a throughput of 54 Mb/s (30 Mb/s of real throughput)
WiFi 802.11b for a throughput of 11 Mb/s (6 Mb/s of real throughput) with a range of up to 300 meters in an open environment
WiFi 802.11g for a throughput of 54 Mb/s (30 Mb/s of real throughput) on a frequency band of 2.4 GHz.
Some laptops are equipped with Bluetooth technology, which is another wireless network technology. However, it is used primarily for wireless personal area network (WPAN), i.e. it is intended for small wireless devices such as mobile phones, PDAs, etc.
IrDa (infrared) technology allows users to connect small devices wirelessly to each other but, unlike BlueTooth technology, has distance limitations (several dozen centimetres facing each other) and reduced throughput.
Technical Characteristics
When you buy a laptop computers, in addition to choosing specific hardware elements you should carefully weigh the following characteristics:
weight: a laptop computer is made to be transported, so it is important to choose the lightest one possible. Nevertheless, watch out for laptops that are light and have many external peripherals (CD-ROM/DVD-ROM drive, mouse, power supply, hubs, etc.)
autonomy: Computer autonomy depends on how much energy a computer's components use as well as the battery's characteristics
NiCad (Nickel / Cadmium): a rechargeable battery that is now obsolete because it suffered from the memory effect, i.e. a progressive decrease in the maximum charge when it is recharged when it is not completely "dead"
NiMH (Nickel / Hybrid Metal): a rechargeable battery that works better than nickel-cadmium batteries
Li-Ion (Lithium / Ion): a rechargeable battery used in most laptop computers. Li-Ion batteries perform well and are reasonably priced. Moreover, Li-Ion batteries do not suffer from the memory effect, which means that it is not necessary to run the battery dry before recharging it.
Li-Polymer (Lithium / Polymer): a rechargeable battery that is equivalent to Li-Ion batteries in terms of performance but is much lighter because the battery electrolytes and microporous separator in Li-Ion batteries are replaced by a solid polymer that is much lighter. On the other hand, Li-Polymer batteries take longer to charge and their longevity is shorter
Generally, computer autonomy is expressed in the amount of time that a computer can remain in sleep mode and in use.
Operating Temperature: Running certain parts of a laptop computer (particularly the processor) causes the temperature of the computer to increase and sometimes become bothersome (especially when the keyboard becomes too hot).
Overheating can become a real danger that can worsen when the laptop is running with the screen down because this can prevent proper thermal dissipation.
noise: In order to dissipate the heat caused by the running of different parts of the laptop (especially the processor), laptop computers are sometimes equipped with heat evacuation devices, such as fans, that can create loud, bothersome noises. This is also true for that motors that run the hard drives and CD/DVD drives/burners. Therefore, it is a good idea for buyers to enquire about the level of noise the computer makes when it runs.
Docking Station
Some laptops come with a docking station. This is the device that the laptop computer fits into in order to easily connect it with a keyboard, mouse, screen, etc.
Warranty
Buying a laptop computer is a big investment. Therefore it is necessary to protect yourself against the risks associated with computer failure by signing up for a warranty. The warranty is even more important for laptop computers because it is not possible to change parts (graphics card, sound card, etc.) like you can on desktop computers. Most offers automatically include at least one year but it might be a good idea to take a several year warranty extension in order to cover the maximum number of risks.
Make sure you get information about the type of damages that are covered by the warranty. Batteries in particular are rarely covered.
Software Package
Laptop computers are almost systematically equipped with an operating system when you purchase them but some offers also include a whole package of useful software such as office tools, an encyclopaedia or even antivirus software. It is a good idea to keep this in mind when you are buying a laptop.
Protective Cover
If you are going to travel with your computer, it is necessary to have a computer bag in order to protect it when transporting it with all its accessories.
In addition, it is highly recommended that you invest in a security cable (Kensington ComboSaver), which allows you to attach the laptop to a fixed piece of furniture thanks to the standard notch that is found on almost all laptops on the market.
However, given its reduced size, most of a laptop computer's pieces are integrated and therefore cannot be changed. This is why users must choose their laptop's characteristics once they are well-informed and have their planned use in mind. On the other hand, the fact that the manufacturer integrates the components allows for reduced risk of hardware incompatibilities (hardware conflicts).
What is a Laptop Computer?
A laptop computer (also called notebook computer) is a computer that integrates all the elements that needs to run properly, including a battery power supply, a screen and a keyboard, in a small casing (on average 360 cm x 40 cm x 270 cm).
Why a Laptop?
The main advantage of a laptop computer versus a desktop computer is its mobility as well as its reduced size. On the other hand, the price is generally higher for slightly less impressive performance and the laptop's hardware configuration is much less adaptable, even though it is possible to connect additional external peripherals thanks to its numerous I/O ports. Therefore, the motivation for buying a laptop computer must above all be a need for mobility or a need to save space.
Moreover, with the emergence of wireless networks, and WiFi in particular, it is becoming very easy to connect to the Internet in public Hot-Spots or simply in any room of your home as long as it is equipped with a WiFi terminal.
For advanced multimedia uses (e.g. digital video manipulation, connecting a digital camera or an mp3 player, etc.), the choice should fall on both the computer's performance (both graphic as well as computing power) and on the types and number of I/O ports that are available.
Processor and RAM
The processor represents the computer's brain in that it processes the instructions. Its execution speed depends on its frequency (in MHz), but two processors from different brands that have very different frequencies can perform equally.
Even though a processor's frequency is still an essential criterion for choosing a laptop computer, today it is preferable to favour the quality of all the components (graphics card, memory, etc.) over only the processor's frequency.
What is more, the quantity of random access memory (RAM) can have a considerable effect on performance, notably when it comes to multimedia use. In addition to the quantity of memory, it is also important to pay attention to its working frequency, which corresponds to the frequency that most of the peripherals will run on.
Screen
Laptop computers have flat screens. Most of the time they are active matrix screens (generally with the TFT, Thin Film transistor technology), i.e. each pixel is individually controlled, allowing for improved display fluidity over passive matrix screens, on which pixels are controlled by line and by column. The latest generations of laptops have favoured active matrix screens over passive matrix screens.
The screen is distinguished first of all by its size, which is expressed in inches (an inch equals 2.54 cm) and corresponds to the screen's diagonal length. Unlike screens with cathode ray tubes (CRT screens), the diagonal length of a flat screen corresponds to the effective display area. Moreover, considering the liquid crystal based technologies used in flat screens, the screen quality of a flat screen can be defined by the response time, which is the length of time necessary to turn a pixel from white to black and then back to white.
The display format is generally 4:3 (i.e. 4 units wide to 3 units high), but there are more exotic laptop display formats that are close to 16:9, such as 15:10, which is adapted to viewing video sequences (e.g. watching DVDs). In general, this type of screen has does not have a whole number diagonal length (e.g. 15.4 inches).
Hard Drive
The hard drive is the area where all the computer's data is stored unlike the RAM, which is a volatile memory that only acts as an information transit area while the computer is running. The most important characteristic of the hard drive is its capacity (expressed in gigabytes), because it determines the amount of data (and, in particular, programs) that a user can store on it. However, it is a good idea to pay particular attention to its performances (in relation notably to its spindle speed), which can hamper the system's overall capacities if they are too weak.
Using external hard drives (FireWire or USB 2.0) can nevertheless enhance a laptop computer by wiping out the intrinsic limitations of its standard hard drives and extending its storage capacity ad infinitum.
Graphics Card
A laptop computer's graphics card is integrated, i.e. it is a specialised graphics chip (graphic chipset) that is soldered to the motherboard. It is impossible to change it once the laptop has been purchased. Therefore, if the laptop computer will be used for graphics applications (video visualisation or manipulation, video games, 3D applications, etc.), it is best to choose a top-of-the-line graphics chipset.
CD/DVD Drive or Burner
More and more laptop computers are making a CD-ROM or a DVD-ROM drive or even a burner into standard features on high-level configurations. When the drive combines several of these functions, it is called a "combo".
There are different types of CD (with a capacity of about 700 Mb) and DVD (with a capacity of about 4.7 Gb) burners.
The term "CD-R" refers to recordable compact disks
The term "CD-RW" refers to rewritable compact disks
The term "DVD-R" refers to recordable DVDs
The term "DVD-RAM" refers to rewritable DVDs Thus, there are two incompatible standards promoted by different manufacturer consortiums:
DVD+RW, by Philips, that have performances in terms of recording time that are generally slightly better than the DVD-RW format
DVD-RW, which cost slightly less than DVD+RWs
It should be noted that some burners support both of these standards and thus are called "multi-format" burners.
Input/Output Interfaces
Input/output interfaces allow you to extend a laptop computer's functionalities by connecting external peripherals. Laptops generally have PC Card connectors (PCMCIA) that allow you to insert additional peripherals.
USB ports are available on all recent laptop computers but it is a good idea to verify if they are USB 1.0 ports, which offer a peak throughput of 12 Mbit/s, or USB 2.0 ports, which can have a peak throughput of up to 480 Mbit/s!
Having IEEE 1394 ports (with the commercial name of FireWire on Apple machines and i.LINK on IBM compatible machines) is a good idea for those users acquiring video from a DV digital video camera. FireWire ports allow throughputs on the order of 800 Mbit/s!
Some laptops come standard with multi-card readers that can read flash memories in the following different formats: Secure digital (SD Card), Multimedia Card (MMC), Memory stick (MS), SmartMedia (SM), Compact Flash (CF) or xD picture card. This type of reader can be extremely practical for those people who have MP3 players, digital cameras or personal desktop assistants (PDAs) because it facilitates the direct copying of files (e.g. music or digital photos) at a high bandwidth.
Audio and Video Input/Output
Every laptop computer has a screen and internal speakers but in some circumstances it is useful or even necessary to connect it to higher performance stereo or video systems (e.g. for a presentation or for a DVD projection).
Laptop computers come standard with a VGA connector, which allows you to connect them to an external monitor or a video projector. Sometimes laptops come equipped with a video output (called a TV output), i.e. a S-Video connector that allows you to connect the computer directly to a television.
With regard to audio I/O, all laptop computers come with standard headphone and microphone jacks as well as stereo speakers of varying quality. Having a S/PDIF output (digital audio output) can allow users to connect their laptop to a sound system that supports Dolby Digital 5.1 (e.g. for Home Cinema use).
Pointing Device / Keyboard
Laptop computers come standard with an integrated keyboard and pointing device. The pointing device is generally a touchpad, i.e. a flat touch-sensitive surface that allows you to move the cursor like a mouse. Some laptops come equipped with a trackpoint, i.e. a little touch-sensitive eraser-like tip (generally red) located in the middle of the keyboard that allows users to move the cursor with their fingers.
The keyboard and pointing device should be chosen according to their ergonomics. They should be tried out in order to determine if they are comfortable to use.
It should be noted that nothing prevents users from connecting a traditional mouse to a laptop computer for more comfort.
Mobility and Network Connectivity
In the communications world that we live in today, it is impossible to imagine a laptop computer without network functionalities. The terms nomadism and mobility are used to refer to individuals' capacity to have access to their information over the Internet, no matter where they are.
Most laptop computers come standard equipped with a 56K V90 modem that allows them to connect to the Internet over the telephone network (STN, switched telephone network).
The "10/100 Mbit Fast Ethernet" connector can be used to connect a laptop to a local area network (LAN) or to connect it to network equipment such as an ADSL modem, a router, a switch or even directly to another computer with a crossover network cable.
With the emergence of wireless networks and the increased number of public and private wireless network access points (called hot spots), the concept of nomadism is taking on a whole new meaning. Thus, some laptop computers now come standard with built-in or card WiFi adapters. WiFi technology allows computers equipped with specialised adapters (WiFi cards) to connect with each other over a range of several dozen or even hundreds of meters and possibly even to connect to the Internet thanks to a wireless router (WiFi terminal). There are several WiFi standards that use different transmission channels:
WiFi 802.11a for a throughput of 54 Mb/s (30 Mb/s of real throughput)
WiFi 802.11b for a throughput of 11 Mb/s (6 Mb/s of real throughput) with a range of up to 300 meters in an open environment
WiFi 802.11g for a throughput of 54 Mb/s (30 Mb/s of real throughput) on a frequency band of 2.4 GHz.
Some laptops are equipped with Bluetooth technology, which is another wireless network technology. However, it is used primarily for wireless personal area network (WPAN), i.e. it is intended for small wireless devices such as mobile phones, PDAs, etc.
IrDa (infrared) technology allows users to connect small devices wirelessly to each other but, unlike BlueTooth technology, has distance limitations (several dozen centimetres facing each other) and reduced throughput.
Technical Characteristics
When you buy a laptop computers, in addition to choosing specific hardware elements you should carefully weigh the following characteristics:
weight: a laptop computer is made to be transported, so it is important to choose the lightest one possible. Nevertheless, watch out for laptops that are light and have many external peripherals (CD-ROM/DVD-ROM drive, mouse, power supply, hubs, etc.)
autonomy: Computer autonomy depends on how much energy a computer's components use as well as the battery's characteristics
NiCad (Nickel / Cadmium): a rechargeable battery that is now obsolete because it suffered from the memory effect, i.e. a progressive decrease in the maximum charge when it is recharged when it is not completely "dead"
NiMH (Nickel / Hybrid Metal): a rechargeable battery that works better than nickel-cadmium batteries
Li-Ion (Lithium / Ion): a rechargeable battery used in most laptop computers. Li-Ion batteries perform well and are reasonably priced. Moreover, Li-Ion batteries do not suffer from the memory effect, which means that it is not necessary to run the battery dry before recharging it.
Li-Polymer (Lithium / Polymer): a rechargeable battery that is equivalent to Li-Ion batteries in terms of performance but is much lighter because the battery electrolytes and microporous separator in Li-Ion batteries are replaced by a solid polymer that is much lighter. On the other hand, Li-Polymer batteries take longer to charge and their longevity is shorter
Generally, computer autonomy is expressed in the amount of time that a computer can remain in sleep mode and in use.
Operating Temperature: Running certain parts of a laptop computer (particularly the processor) causes the temperature of the computer to increase and sometimes become bothersome (especially when the keyboard becomes too hot).
Overheating can become a real danger that can worsen when the laptop is running with the screen down because this can prevent proper thermal dissipation.
noise: In order to dissipate the heat caused by the running of different parts of the laptop (especially the processor), laptop computers are sometimes equipped with heat evacuation devices, such as fans, that can create loud, bothersome noises. This is also true for that motors that run the hard drives and CD/DVD drives/burners. Therefore, it is a good idea for buyers to enquire about the level of noise the computer makes when it runs.
Docking Station
Some laptops come with a docking station. This is the device that the laptop computer fits into in order to easily connect it with a keyboard, mouse, screen, etc.
Warranty
Buying a laptop computer is a big investment. Therefore it is necessary to protect yourself against the risks associated with computer failure by signing up for a warranty. The warranty is even more important for laptop computers because it is not possible to change parts (graphics card, sound card, etc.) like you can on desktop computers. Most offers automatically include at least one year but it might be a good idea to take a several year warranty extension in order to cover the maximum number of risks.
Make sure you get information about the type of damages that are covered by the warranty. Batteries in particular are rarely covered.
Software Package
Laptop computers are almost systematically equipped with an operating system when you purchase them but some offers also include a whole package of useful software such as office tools, an encyclopaedia or even antivirus software. It is a good idea to keep this in mind when you are buying a laptop.
Protective Cover
If you are going to travel with your computer, it is necessary to have a computer bag in order to protect it when transporting it with all its accessories.
In addition, it is highly recommended that you invest in a security cable (Kensington ComboSaver), which allows you to attach the laptop to a fixed piece of furniture thanks to the standard notch that is found on almost all laptops on the market.
Types of computers
Types of computers
There are several families of computers, depending on their format:
Mainframes, computers which a great deal of computing power, enormous input-output capabilities and high level of reliability. Mainframes are used by large companies to carry out heavy computing operations are large volumes of data processing. Mainframes are normally used in centralised architectures, in which they are the heart.
Personal computers, including, Desktop computers, made up of a case which houses a motherboard and allows users to connect multiple peripheral devices such as the screen.
Laptop computers, made of a case with a fold-out screen, a keyboard, and many onboard devices.
Tablet PCs, made of a case which integrates a touch-screen and a certain number of onboard devices.
Media centres, which represent a hardware platform, intended to be used in living rooms for running hifi elements (such as a hifi sound system, television set, DVD player, etc.)
Personal digital assistants (called PDAs, or handhelds), sometimes known as organisers or electronic datebooks, are pocket computers with features for personal organisation.
There are several families of computers, depending on their format:
Mainframes, computers which a great deal of computing power, enormous input-output capabilities and high level of reliability. Mainframes are used by large companies to carry out heavy computing operations are large volumes of data processing. Mainframes are normally used in centralised architectures, in which they are the heart.
Personal computers, including, Desktop computers, made up of a case which houses a motherboard and allows users to connect multiple peripheral devices such as the screen.
Laptop computers, made of a case with a fold-out screen, a keyboard, and many onboard devices.
Tablet PCs, made of a case which integrates a touch-screen and a certain number of onboard devices.
Media centres, which represent a hardware platform, intended to be used in living rooms for running hifi elements (such as a hifi sound system, television set, DVD player, etc.)
Personal digital assistants (called PDAs, or handhelds), sometimes known as organisers or electronic datebooks, are pocket computers with features for personal organisation.
Computer - Components
Introduction to the Concept of the Computer
Understanding computer vocabulary is the main difficulty that potential personal computer buyers face. Unlike buying a TV, a task for which the decision-making criteria are limited, choosing a computer requires choosing each of its components and knowing their characteristics. The purpose of this document is not to make sense of all the computer abbreviations (because each manufacturer has their own technologies) but rather to profile the main components of a computer, explain how they work and outline their main characteristics.
Presentation of the Computer
A computer is a set of electronic circuits that allow for data to be manipulated in binary form, i.e. in bits. The French word for computer, "ordinateur", was invented by the company IBM France. François Girard, who in 1955 was in charge of IBM France's advertising department, had the idea to seek advice from his former arts professor in Paris in order to ask him to suggest a word that described as best as possible the device that was commonly being called a "calculateur" (the literal translation of the English word "computer").
Thus, Jaques Perret, said arts professor who was at that time teaching Latin philology at the Sorbonne, suggested on 1 April 1955 the word "ordinateur", specifying that the word "ordinateur" was an adjective from the word littré meaning "God making order in the world". He explained that the concept of "making order" was perfectly adapted to the object at hand.
Types of Computers
Any machine capable of manipulating binary information can be considered a computer. However, the term "computer" is sometimes confused with the term personal computer (PC), which is the type of computer that is most commonly found on the market. And yet there are many other types of computers (the following is not an exhaustive list):
Amiga
Atari
Apple Macintosh
Alpha stations
SUN stations
Silicon Graphics stations
The rest of this document, as generic as it might be, applies particularly to PC type computers. They are also called IBM-compatible computers because IBM is the company that created the first of these computers models and was for a long time (until 1987) the leader in this area, so much so that they controlled the standards, which were copied by other manufacturers.
Make-up of a Computer
A computer is a collection of modular electronic components, i.e. components that can be replaced by other components that may have different characteristics that are capable of running computer programs. Thus, the term "hardware" refers to all the material elements of a computer and "software" refers to the program parts.
The material components of the computer are structured around a main board that is made up of a few integrated circuits and many electronic components such as capacitors, resistors, etc. All these components are fused to the board and are linked by circuit board connections and by a large number of connectors. This board is called the motherboard.
The motherboard is housed in a casing (or frame) that comprises slots for memory peripherals on the front, buttons that allow you to switch the computer on and off, as well as a certain number of indicator lights that allow you to verify the computer's operating state and the activity of the hard drives. On the back, the casing has openings facing the expansion boards and the I/O interfaces, which are connected to the motherboard.
Finally, the casing houses an electrical power supply (commonly called the power), which is in charge of providing a stable and continuous electrical current to all of the elements that make up the computer. The power supply converts alternating current from the power grid (220 or 110 volts) into a direct voltage of 5 volts for the computer components and 12 volts for some internal peripherals (drives, CD-ROM drives, etc.). How powerful the electrical supply is determines how many peripherals the computer is capable of supplying. The power supply is generally between 200 and 450 Watts.
The "central processing unit" includes the casing and all the elements it contains. The external elements of the central processing unit are called peripherals.
The central processing unit must be connected to a whole set of external peripherals. A computer generally comprises at least the central processing unit, a screen (monitor), a keyboard and a mouse, but it is possible to connect a wide range of peripherals on the I/O interfaces (serial ports, parallel ports, USB ports, FireWire ports, etc.):
a printer
a scanner
an external sound card
an external hard drive
an external storage peripheral
a digital camera or video camera
a PDA
etc.
Understanding computer vocabulary is the main difficulty that potential personal computer buyers face. Unlike buying a TV, a task for which the decision-making criteria are limited, choosing a computer requires choosing each of its components and knowing their characteristics. The purpose of this document is not to make sense of all the computer abbreviations (because each manufacturer has their own technologies) but rather to profile the main components of a computer, explain how they work and outline their main characteristics.
Presentation of the Computer
A computer is a set of electronic circuits that allow for data to be manipulated in binary form, i.e. in bits. The French word for computer, "ordinateur", was invented by the company IBM France. François Girard, who in 1955 was in charge of IBM France's advertising department, had the idea to seek advice from his former arts professor in Paris in order to ask him to suggest a word that described as best as possible the device that was commonly being called a "calculateur" (the literal translation of the English word "computer").
Thus, Jaques Perret, said arts professor who was at that time teaching Latin philology at the Sorbonne, suggested on 1 April 1955 the word "ordinateur", specifying that the word "ordinateur" was an adjective from the word littré meaning "God making order in the world". He explained that the concept of "making order" was perfectly adapted to the object at hand.
Types of Computers
Any machine capable of manipulating binary information can be considered a computer. However, the term "computer" is sometimes confused with the term personal computer (PC), which is the type of computer that is most commonly found on the market. And yet there are many other types of computers (the following is not an exhaustive list):
Amiga
Atari
Apple Macintosh
Alpha stations
SUN stations
Silicon Graphics stations
The rest of this document, as generic as it might be, applies particularly to PC type computers. They are also called IBM-compatible computers because IBM is the company that created the first of these computers models and was for a long time (until 1987) the leader in this area, so much so that they controlled the standards, which were copied by other manufacturers.
Make-up of a Computer
A computer is a collection of modular electronic components, i.e. components that can be replaced by other components that may have different characteristics that are capable of running computer programs. Thus, the term "hardware" refers to all the material elements of a computer and "software" refers to the program parts.
The material components of the computer are structured around a main board that is made up of a few integrated circuits and many electronic components such as capacitors, resistors, etc. All these components are fused to the board and are linked by circuit board connections and by a large number of connectors. This board is called the motherboard.
The motherboard is housed in a casing (or frame) that comprises slots for memory peripherals on the front, buttons that allow you to switch the computer on and off, as well as a certain number of indicator lights that allow you to verify the computer's operating state and the activity of the hard drives. On the back, the casing has openings facing the expansion boards and the I/O interfaces, which are connected to the motherboard.
Finally, the casing houses an electrical power supply (commonly called the power), which is in charge of providing a stable and continuous electrical current to all of the elements that make up the computer. The power supply converts alternating current from the power grid (220 or 110 volts) into a direct voltage of 5 volts for the computer components and 12 volts for some internal peripherals (drives, CD-ROM drives, etc.). How powerful the electrical supply is determines how many peripherals the computer is capable of supplying. The power supply is generally between 200 and 450 Watts.
The "central processing unit" includes the casing and all the elements it contains. The external elements of the central processing unit are called peripherals.
The central processing unit must be connected to a whole set of external peripherals. A computer generally comprises at least the central processing unit, a screen (monitor), a keyboard and a mouse, but it is possible to connect a wide range of peripherals on the I/O interfaces (serial ports, parallel ports, USB ports, FireWire ports, etc.):
a printer
a scanner
an external sound card
an external hard drive
an external storage peripheral
a digital camera or video camera
a PDA
etc.
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