The Representation of Data in a Computer - Essay Example

1. Write a short report with examples to show how a computer system that only works with binary data can be used to store and process multimedia datasuch as text, images, sound as well as numeric data. The representation of data in a computer is very different from the way it is represented in real world. Data might in the form of text, image ,sound or numbers .But whatever may be the form of data , a computer recognizes only 0's and 1's and therefore a user's data needs to be converted into appropriate binary form to be able to be processed by a computer . The methods for doing the same are described as below. Text: Textual information like a file or a document comprises of a collection of numbers, characters and special characters for example punctuation marks and symbols. A computer uses the following procedures for the conversion of Text to binary Conversion of Numbers to Binary Decimal numbers are the numbers whose base is 10 i.e. it uses ten digits (0 to 9) to represent the values, while binary is the number system whose base is two, it uses 0's and 1's to represent the numbers. For Integers Each binary bit has a position assigned to it. The zeroeth position is assigned to the least significant position on the right most side. The 0 or 1 at the respective position is then multiplied by the corresponding power of two to obtain its decimal equivalent i.e. A digit at Kth position is multiplied by 2 ^(k-1). For example (1101)2= 1 x 23 + 1 x 22 + 0 x 21 + 1 x 20= (13)10 For Real numbers Real numbers may be put into binary scientific notation: a x 2^b .The number to the right of decimal part must be multiplied by negative powers two of the corresponding position .The number to the left hand side must be multiplied by the positive powers of two. Mantissa and exponent are then stored .For example 0.21875 = 7/32 = 1/8 + 1/16 + 1/32 = 0.00111 0.375 = 3/8 = 1/4 + 1/8 = 0.011 0.1875 = 5/16 = 1/4 + 1/16 = 0.0101 For Character and Punctuation marks The characters and punctuation marks are encoded for their representation in binary form. The procedure is described as follows Each and every character, symbol or punctuation mark is mapped to a corresponding decimal number .For example letter K is mapped to number 75, the number is then encoded by using ASCII code to a string of Binary numbers. ASCII stands for American Standard Code for Information Interchange. It is an 8-bit code, which contains in all 128 characters (uppercase and lowercase letters, numbers, punctuation, symbols, and some non-printing characters such as the blank space). For example, the code for "I am" would be: 73 - 01001001 - code for I 32 - 00100000 - code for space 97 - 01100001 - code for a 109 - 01101101 - code for m 46 - 00101110 - code for period REPRESENTATION OF IMAGE: To store an image, like a photograph, in binary form, a computer superimposes a grid on that photograph. Each pixel or grid contains one "dot" of color. In order to store data for that pixel in memory; the information about that pixel's color must somehow be converted to a binary number. There are various ways to do this which serve to map a pixel to binary numbers. Different ways or methods associate different number of bits with each pixel. There are two main formats in which images are stored in the computer - bitmap (or raster) and vector. In vector representation, all components of the image are stored using mathematical formulas. In a bitmap image, the image is stored in memory by recording some piece of binary data corresponding to each pixel of the image. The number of bits used to store each pixel affects both the image quality and the amount of memory that will be needed to store the image. There are various scales for coding the colors, one being grayscale in which 1 represents black and 0 represents white. Each pixel in a grayscale image can be stored using 1 byte (8 bits). To represent colored images 16-color, 256 color, and RGB color (or true color) color codes are used. Each of the different code requires different numbers of bits and produces different image quality. Representation of Sound: Representation of sound requires conversion of analog waveform to digital waveform, through the use of a procedure called sampling. The sound is a analog signal whose amplitude continuously varies with time .A sampler samples this amplitude at discrete interval of time to generate a stream of 0's and 1's .The process of measuring and recording the voltage of the signal is called sampling and there are two main factors that determine its accuracy. One factor is how often the wave is measured called the sampling rate and the other is taking a more accurate measurement known as sampling precision. The more readings taken with more precise unit of measurement, more is the accuracy of conversion (and eventually better sound reproduction). In order to achieve a CD quality recording, the analog signal must be read approximately 44,000 times in a second. This is huge in terms of memory as more the number of bits more the memory required for their storage. If the sampling rate drops below this level, the human ear detects distortions in the recording. In addition to the sampling rate, the more bits (or bytes) dedicated to taking the voltage reading the better the sound reproduction. , Recording sounds (and music) require significant amounts of memory. But again, there are data compression techniques that reduce file size without sacrificing quality. 2. You have been lucky to win a student competition to equip yourself with some computing equipment. You are able to select a PDA, a desktop machine and a laptop computer from manufacturers of your choice. You are required to find detailed specifications for each of the items. Write a well structured report that will:- a)Explain, for each, on a line by line basis, the general meaning of the specifications. Ans: Computers have become necessity in all fields of life, be it education, services, business or hospitals. They have revolutionalized the way people do things by adding speed and efficiency to the process. Due to such ubiquitous needs of computer they are available in different forms, equipped with different forms to meet the different kind of needs of a user. Three common being PDA's, Laptop's and Desktop's. Their specification along with a few other applications and attributes are presented below. Laptop specification HP Compaq 2710p Notebook PC Cost: 2328 Processor type Intel Core2 Duo Processor U7600 - 1.20 GHz, 2 MB L2 cache, 533 MHz FSB A faster processor supports more efficient operations and improves application's performance therefore it becomes a parameter to judge how fast your computer does things. Operating system installed Genuine Windows Vista Business The main control program of your system that makes your computer work. Chipset Mobile Intel GM965 The architecture of chipset Standard memory 1 x 1024 MB DDR2 More the memory more the programs you can run on your computer. Memory slots 2 SODIMM slots supporting dual channel memory Slots to add more memory units to Laptop when you need more space for storage. Memory upgrade Upgradeable to 4096 MB maximum Maximum memory that can be added to your computer or its maximum storage capacity. Internal hard disk drive 100 GB Hard drive is the primary storage for your programs and files Hard disk drive speed 4200 rpm The speed of retrieval of data from Hard drive is directly proportional to its rpm or rotations per minute Weight Starting at 1.6 kg (weight will vary by configuration) The weight determines the ease of mobility of a laptop .the lesser it is the easier it becomes to carry. Dimensions (W x D x H) 29.0 x 21.2 x 2.82 (at front) cm The length, width and height of laptop Display size 12.1 inches diagonal The size of a LCD display Wireless technologies Intel Wireless LAN 802.11a/b/g, Blue tooth 2.0+ Wireless connectivity interfaces supported so you can connect Blue tooth, infrared etc. Network interface Integrated Intel Gigabit Network Connection (10/100/1000 NIC) LAN Functionality supported on Laptop, so you can get connected to your friends network or university LAN Expansion slots ExpressCard/54 slot supports ExpressCard/54 and ExpressCard/34, integrated Smart Card Reader, Secure Digital slot Additional hardware devices slots that can be configured to add more features. External I/O ports Smart Card Reader, external monitor, 1394a, stereo microphone in, stereo, headphone/line out, power connector, RJ-11/modem, RJ-45/Ethernet, USB 2.0, docking connector Other ports to connect headphones, an additional monitor or telephone line, to enjoy music or web conferencing. Software included HP Backup and Recovery Manager, HP Help and Support Center, HP QuickLook (Windows Vista only), HP OpenView Radia Management Agent, HP Universal Print Driver, HP ProtectTools Security Manager, HP Quick Launch Buttons, HP Wireless Assistant, Roxio Creator 9 (for optional DVD+/-RW and DVD/CDRW drives), Intervideo WinDVD Packaged proprietary software that include drivers and diagnostic softwares to troubleshoot the computer when it shows some problem . Graphic subsystem name Mobile Intel Graphics Media Accelerator X3100 Provides high resolution and accelerated interface for Games so that you can enjoy the games. Graphic subsystem video card memory Up to 384 MB shared system memory The additional memory for playing high speed games Keyboard Full-sized keyboard Standard Input device a typical QWERTY Keyboard Pointing device Enhanced dual pointing devices (touch pad and point stick) with scroll zone Auxiliary input device Warranty standard statement 3 years standard parts and labour limited warranty, depending on country (upgrades available), 1 year warranty on primary battery Warranty specifications Power features 6-cell (44 WHr) Lithium-Ion battery Battery backup and configuration to charge your Laptop Power requirements External 65W HP Smart AC Adapter, HP Fast Charge Power set up Security management HP ProtectTools Security Manager, HP Fingerprint Sensor, TPM 1.2 Embedded Security Chip, TPM Enhanced DriveLock, HP Disk Sanitizer, HP 3D DriveGuard, Kensington Lock slot, Symantec Norton Internet Security Stay protected from the latest online threats when connecting to the Web or any external or internal intrusion or outage. DESKTOP MACHINE SPECIFICATIONS HP Pavilion a6500z series Cost: 439 Operating system The main control program of your system. Windows Vista Home Premium with Service Pack 1 (32-bit) Processor A faster processor supports more efficient operations and applications performance AMD Sempron(TM) LE1300 (2.3GHz) Memory Use more programs at once and make them run faster with more memory 2GB DDR2-800MHz dual channel SDRAM (2x1024 Graphics card Bring your favorite applications and games to life Integrated NVIDIA GeForce 6150 SE, VGA 128MB NVIDIA GeForce 9300, DVI-I, VGA Networking Go wireless with the wireless card 56Kbps Data/Fax Modem for dial-up Internet access 802.11 b/g Wireless LAN card 802.11 b/g Wireless LAN and 56K data/fax modem Hard drive Holds the data, digital music, digital photos and other files and necessary documents. 250GB 7200 rpm SATA 3Gb/s hard drive Primary CD/DVD drive Optical drives can be used to store data, play music and movies, and burn CDs or DVDs LightScribe 16X max. DVD+/-R/RW SuperMulti drive Front Productivity Ports Get the ports you use most at the front for easy accessibility. 2 USB, front audio ports 15-in-1 memory card reader, 2 USB, audio Sound Card Music and games truly come alive in your stereo or computer speakers with the help of a sound card Integrated 5.1 Capable Sound w/ front audio ports Sound Blaster X-Fi Xtreme Audio Security software Stay protected from the latest online threats when connecting to the Web. Norton Internet Security(TM) 2008 - 15 month Norton Internet Security(TM) 2008 - 2 year Norton Internet Security(TM) 2008 - 3 year HP Featured Software Software to help you get the most out of your PC. JumpStart World(TM) Kindergarten JumpStart World(TM) 2nd Grade JumpStart World(TM) 1st Grade Easy Bits Magic Desktop Back-up & media management Protect your valuable files. Synch up with mobile devices ArcSoft MediaConverter 2.5 Roxio BackUp MyPC 7 Productivity software Get the tools you need to save time and improve productivity Microsoft(R) Works 9.0 Finance & accounting software Track your income and expenses with a financial software package for your home or business Quicken Deluxe 2008 QuickBooks Pro Edition 2008 Premium photography software Software that helps you make the most of your digital cameras and brings your pictures to life! Roxio Photo Suite 9 Deluxe Speakers Enhance your PC with high-quality external powered speakers HP stereo speakers (2.0) Keyboard and Mouse Upgrade to internet keyboard to make surfing the web a cakewalk HP keyboard and HP optical mouse HP multimedia keyboard and HP optical mouse HP wireless keyboard and HP wireless optical mouse Weight Weight of Desktop 9.6 kG Dimensions Width: 17.5 cm. Depth: 41.6 cm. Height: 35.3 PDA SPECIFICATIONS MODEL: HP iPAQ hw6515 Unlocked Mobile Messenger (FA385A) Cost: 422.99 Operating system Genuine Windows Mobile 2003 for Pocket PC-2nd Edition An operating system is the software component of a computer system that is responsible for the management and coordination of activities and the sharing of the resources on the computer. Processor Intel PXA270 Processor 416 MHz Processor is the decision maker of a PDA .it handles and manipulates data allowing a user to do things. Faster the processor, faster it does things. Available Memory 64 MB SDRAM The amount of memory (RAM or ROM) available to be used by the user for storing data is measure is megabytes (abbreviated MB) and is called Available Memory Flash Memory 64 MB Flash memory is a type of data storage technology that uses no mechanical parts (like a hard drive or floppy disk), but uses electrical currents stored in blocks to save data. Flash memory also performs faster than other memory types. Ports 1 USB 1 IrDA 1 Serial USB port is used to connect to a bulk storage media or data cable, Infrared port is for infrared connectivity while serial port provides the printer and scanner features to be attached to a PDA Slots - 1 Support 1-bit SDIO and 4-bit SD/MMC type memory standard - 1 Support 1-bit and 4-bit SD/MMC type memory standard The slots are used to add more memory to a PDA.SDIO port is used to add more Flash memory. An SD Card (Secure Digital Card) is an ultra small flash memory card designed to provide high-capacity memory in a small size. Display Size 3.0 in Transflective QVGA with 64K Color LED backlight One of the reasons PDAs can be so small is that they have touch screens that pull double duty as displays and input devices Input Devices - Stylus - Integrated QWERTY keyboard with LED backlight Integrated HP Photosmart 1.3 MP Camera PDAs typically use a stylus for navigation and a keyboard for data input, although some models offer handwriting-recognition as an add-on option. Wireless EDGE/GPRS Bluetooth GPS To connect to the network without wires a PDA comes equipped with various wireless features like EDGE, Bluetooth and GPRS Dimensions (h x w x d) 4.65 x 2.8 x 0.71 in (118.0 x 71.0 x18mm) A PDA should be handy and robust with attractive aesthetics Weight 5.8 oz (165.0 g) The weight of a PDA should be less so that it can be carried easily. Power Supply/Battery Lithium -ion, removable, AC adopter with power cable Most PDAs come with rechargeable lithium batteries. Lithium batteries last from a week to a month with intermittent use. They recharge easily in a couple of hours by placing them in their synch cradle or plugging them in with a charging cable. 2b) Discuss the differences between the specifications for each machine and explain why they are different. The Laptop, Desktop and PDA are essentially different and intended for different kind of usage. A PDA has limited capabilities in terms of memory, processor speed and input/output ease as compared to Laptop or Desktop but is quite handy and can easily be carried along. A laptop is equipped with everything to perform high-end computations but comes with a high cost, while a Desktop although is not as costly as Laptop but cannot be carried along easily as it is heavy and large. The differences reflected in specifications is explained as below i) Weight: PDA is the smallest of the three and high on convenience for mobility Its weight ranges from 149 to 200 grams while the weight of a Laptop is 1.6 Kg, The Desktop which is not intended to be carried along with the user weighs much heavier, starting from 2.78 Kg. PDA and Laptop are designed to be carried along while a Desktop is more for stationary usage; therefore PDA's and Laptops are lighter as compared to Desktop. ii) Dimensions: The length width and height of a PDA are smallest 118.0 x 71.0 x18mm), while that of a Laptop are 290.0 x 212 x 28.2 (at front) mm, that of a Desktop are 175 cm X 410 cm X535 cms. Owing to small dimension a student can easily carry PDA and Laptop while cannot do the same with a desktop. iii) LCD Display: The PDA has the smallest LCD display, followed by the LCD display of a Laptop and then the biggest display is that of a desktop. Therefore a student who needs to view a large file has to scroll along in a PDA while a Laptop and Desktop can easily provide optimum display for a large file. iv) PDA has limited memory that essentially ranges in MB while Desktop and laptop have memories in the range of GB's. Therefore if a student needs to store a lot of data then he should chose Laptop or Desktop. v) The battery life of a PDA is largest as its processor is of limited speed while life of battery of a Laptop is limited to 3 -6 hours and requires frequent recharging, a Desktop, which is generally connected to a UPS, does not require charging vi) Software Limitations: A PDA supports limited applications while a Laptop and a Desktop have a full-fledged processing capabilities to support high-speed applications like games, publishing and other applications. 2c) Describe the input/output method for each machine and give some indication of how this might limit their use to you as a student Ans: PDA, Laptop and Desktop are designed for different kind of usage and that is reflected in their input /output methods also.Whereas a PDA is a small equipment designed to carried in a pocket , a Laptop is designed to carried over a shoulder while a Desktop is meant for static usage. The Input /Output method of PDA, Desktop and Laptop are summarized as follows PDA LAPTOP DESKTOP INPUT - Stylus - Integrated QWERTY keyboard with LED backlight Integrated HP Photosmart 1.3 MP Full-sized keyboard, mouse, Card Reader, Scanner, Camera CD/DVD Keyboard mouse Card Reader, Scanner, Camera CD/DVD OUTPUT 3.0 in Transflective QVGA with 64K Color LED backlight SPEAKER Premium CD/DVD burner LCD Display SPEAKER Premium CD/DVD burner LCD Display SPEAKER A PDA is highly mobile computing equipment with limited features in terms of memory and processing capabilities. They are durable, inexpensive, and very portable (being worn on a clip or carried in a pocket). Their Display (LCD) is of small size and have a small keyboard and a touchscreen to input data. Because of small screen and small keyboard the data input methods are slow, but they are apt for mobile usage and a quick retrieval of small information like address or connecting to Internet to check mails. A laptop is much more powerful than PDA, but it's not as mobile as a PDA as owing to its size it must be set on some platform to start working on. It has additional feature to read from a CD/DVD drive. The input /output methods are quick and are ideal to be used if computing has to be done on go. But it has a smaller battery life and requires frequent recharging. A desktop is ideal for a student who does not need to carry the computer. It has a keyboard, printer and other peripherals to ease input /output methods .in additions it has memories ranging in GB's and increased hard disk and processing capacities and hence supports all kinds applications ranging from data-entry to high speed games and database processing. 2d) Write a conclusion on the differences between the specifications and intended use of the machines. Answer: A PDA is small sized electronic equipment with a small Display screen, a touch screen to provide a student with retrieval of small amount of data, a music player to play music and an Internet client to provide Internet access. It is designed to be carried in a pocket, but contains programs to operate even when out of range of WiFi or coverage. PDAs are durable, inexpensive, and very portable (being worn on a clip or carried in a pocket). The small screen size and limited ability to quickly enter data are the drawbacks of this device. A Laptop has the same capabilities as that of a desktop, but is of the size and weight that it can be carried along conveniently. It is having a higher price and supports all software that a Desktop supports .It is best solution for the needs of a person who needs to have a portable device with capabilities of a Desktop. A Desktop is ideal for those people who need to perform complex calculations and other high end computing tasks with no mobility .It is cheaper as compared to Laptop and is ideal for a student who needs to access his computer from one location only. References HP Compaq 2710p Notebook PC - Specifications. (2008). In . Retrieved july 24, 2008. http://h10010.www1.hp.com/wwpc/in/en/sm/WF06a/321957-321957-64295-306995-306995-3355644.html HP Pavilion a6500z series .http://www.shopping.hp.com/webapp/shopping/computer_can_series.dostoreName=computer_store&category=desktops&a1=Category&v1=Everyday+computing&series_name=a6500z_series Choosing a PDA versus a Laptop. (2007). Retrieved july 30, 2008, from http://www.googobits.com/articles/1019-choosing-a-pda-versus-a-laptop.html roseberry, catherine. (2008). Laptop or PDA for Business Trips. Retrieved july 30, 2008, from http://mobileoffice.about.com/cs/packyourgear1/a/laptoppda.htm Heather, booth., & Brown, murray. (n.d.). Basics of computer science. Retrieved july 30, 2008, from http://www.cs.utk.edu/modules/acknowledgements.html Read More