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# Computer Basics

Computer Basics Which computer should I buy? What do I get for an extra \$775 and do I even need it ? Desktop We need to understand several things before going out and buying a computer . What are the different components of a computer system and how do they work?

## Computer Basics

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### Presentation Transcript

1. Computer Basics

2. Which computer should I buy? What do I get for an extra \$775 and do I even need it? Desktop

3. We need to understand several things before going out and buying a computer. • What are the different components of a computer system and how do they work? • What are the different options available for each of these components? • How will you be using your computer and therefore which components/options will you need?

4. Basic Computer Components Tower Box: Central Processing Unit - CPU (motherboard), power supply, Main Memory (RAM), Auxiliary Memory devices: Hard drive, CD, DVD, etc. CPU Monitor A Laptop – with CPU, monitor, keyboard, touch pad & speakers keyboard mouse speakers printer

5. Output devices How these Components Work Together Main/Primary Memory (RAM) Bus • CPU- Central Processing Unit • Control Unit • Arithmetic Logic Unit (ALU) Input devices Keyboard, Mouse Monitor, Printer Bus Auxiliary (Secondary) Memory Hard drive CD R/W, DVD, floppy drive, ZIP drive, Flash memory

6. An inside view – the Motherboard Cards: Video, Sound Network, Modem

7. An inside view – Hard Drive & Bus cables Hard Drive Bus

8. User hits the ‘2’ key then Enter MainMemory ALU adds 2 + The user input Program: INPUT X Y = X+2 OUTPUT Y Y = 4 Output 4 on the screen CPU – Central Processing Unit works with memory to execute the arithmetic and logical processes The performance of the CPU is dependent on both its speed and memory

9. Clock Frequency: This is also sometimes called the clock rate or clock speed. It is simply the reciprocal of the cycle time, and is therefore the number of cycles that occur each second (as opposed to the number of seconds per cycle). It is usually measured in MHz or GHz, where "Hz" is the abbreviation for Hertz, the standard SI unit for measuring frequency. One Hertz is one cycle per second. So for example, if a clock's cycle time is 1.25 ns, its frequency is 1/(0.00000000125) = 800,000,000 Hertz, or 800 MHz. • Clock Frequency: This is also sometimes called the clock rate or clock speed. It is simply the reciprocal of the cycle time, and is therefore the number of cycles that occur each second (as opposed to the number of seconds per cycle). It is usually measured in MHz or GHz, where "Hz" is the abbreviation for Hertz, the standard SI unit for measuring frequency. One Hertz is one cycle per second. So for example, if a clock's cycle time is 1.25 ns, its frequency is 1/(0.00000000125) = 800,000,000 Hertz, or 800 MHz. • Clock Frequency: This is also sometimes called the clock rate or clock speed. It is simply the reciprocal of the cycle time, and is therefore the number of cycles that occur each second (as opposed to the number of seconds per cycle). It is usually measured in MHz or GHz, where "Hz" is the abbreviation for Hertz, the standard SI unit for measuring frequency. One Hertz is one cycle per second. So for example, if a clock's cycle time is 1.25 ns, its frequency is 1/(0.00000000125) = 800,000,000 Hertz, or 800 MHz. • Clock Frequency: This is also sometimes called the clock rate or clock speed. It is simply the reciprocal of the cycle time, and is therefore the number of cycles that occur each second (as opposed to the number of seconds per cycle). It is usually measured in MHz or GHz, where "Hz" is the abbreviation for Hertz, the standard SI unit for measuring frequency. One Hertz is one cycle per second. So for example, if a clock's cycle time is 1.25 ns, its frequency is 1/(0.00000000125) = 800,000,000 Hertz, or 800 MHz. • Clock Frequency: This is also sometimes called the clock rate or clock speed. It is simply the reciprocal of the cycle time, and is therefore the number of cycles that occur each second (as opposed to the number of seconds per cycle). It is usually measured in MHz or GHz, where "Hz" is the abbreviation for Hertz, the standard SI unit for measuring frequency. One Hertz is one cycle per second. So for example, if a clock's cycle time is 1.25 ns, its frequency is 1/(0.00000000125) = 800,000,000 Hertz, or 800 MHz. 1.66GHz vs 2.8GHz..whats a GHz? Different Processors have different “clock” speeds and different memory “bus”speeds – A faster clock speed won’t necessarily speed up your processing if the bus speed is too slow! GHz - a unit of frequency equal to one billion cycles per second

10. What is RAM memory? • The performance of a computer is also dependent on the amount of Primary (Main) Memory – Random Access Memory (RAM) available. • This memory temporarily stores information so that it’s readily available to the CPU. This includes the program(s) being executed and required data. • If this memory is limited or slow – this will slow down the computer’s ability to process information.

11. How does Memory Work? • Physically computer memory is made up of transistors & capacitors - the only information they store is a magnetic charges (high & low) represented by a 0 or 1. • Computer scientists combine a series of these transistor states to represent information - They turn information into a “binary” format so it can be easily stored as magnetic charges.

12. How is Information Stored in Memory? All data is represented by a string of 0’s and 1’s. • Integers, Real Numbers, and characters are stored this way. They all are converted to a string of 0’s and 1’s in different ways. • Integers are their base 2 equivalent • Characters are converted via some standard (ASCII, Unicode, etc) All information is translated by a set of instructions into this format and then processed

13. Measuring Memory • Each 0,1- is called a bit • 1 Byte is 8 bits • 1 Kilobyte (KB) = 210 bytes(1111111111) • ≈1000 bytes = 1x103 bytes • 1 Megabyte (MB) = 220 bytes • ≈1,000,000 bytes = 1x106 bytes • 1 Gigabyte (GB) = 230 bytes • ≈1,000,000,000 bytes = 1x109 bytes • 1 MB of memory can hold approximately 500 pages of text.

14. SRAM, DRAM, SDRAM, DDR,RDRAM, ..BLAM.. BLAM SRAM Static Random Access Memory doesn’t need to be “refreshed” - but like all RAM, is erased when the power is OFF CPU 5-10X slower 10 ns speed DRAM (Dynamic RAM) is a type of memory that is constantly refreshed or will loose its contents. SDRAM (Synchronous Dynamic RAM) – designed to work with the CPU clock to work faster than DRAM DDR SDRAM (Double Data Rate SDRAM) – works twice as fast as SDRAM

15. So how much and what type of memory should you get? • It will depend on the type of computer you have/or are buying • Older systems are no always compatible with newer memory types • Sometimes too much memory can cause problems with Windows • It will depend on the applications you wish to run • Photoshop or other graphical applications require much more memory than simple word processing • Do you wish to have many applications running simultaneously?

16. To save data for later use we can store data on Secondary (Auxiliary) Memory devices Auxiliary Memory is cheaper/slower than Primary memory but is not erased when the Power Supply is OFF. • Hard drive – A non-removable device 20-250GB ranges • Floppy disk drive-1.44MB • CD’s & DVD’s – 600 MB. (Read vs. RW) • Removable Hard drives –Zip, Jazz • Memory Sticks

17. Hardware vs. Software • For computer hardware to work it must follow a set of instructions that is supplied to it. These instructions or programs are referred to as software. • Some instructions are referred to as the Operating System Software, which control the basic input/output and memory operations of the computer. • Application Software are programs that work with the Operating system to perform specific tasks.

18. System Software Programs to control computer operations are called Operating Systems (OS) • Instructions on loading and executing applications and transferring data loaded into main memory on startup (booting) • examples: DOS, Unix,, Windows XP, Vista ..and promised soon…. VISTA

19. Applications Software Computer programs written to perform specified tasks. They work in tandem with specific Operating Systems • Word Processing • Spreadsheets • Database Management Systems • Web design software • Internet Access & E-mail • Graphics Packages

20. What software you need will affect you decision of what hardware to buy…For example how much hard drive space will you need with the following requirements? • Windows XP Professional Operating System - *1.5 GB • Full install of MS Office 2003 - *450 MB • Dream Weaver - *800 MB • Adobe’s Photoshop - *280MB • Have room to store my photo album with 150 pictures - .. Average of 500KB each In GB: 1.5+.45+.8+.28+150*.005=3.78

21. What doesn’t this ad tell us? • Is any application software included? • What about a monitor, mouse, speakers etc. • What about getting on the internet?

22. The mouse \$10 • Most standard “systems” come complete with a standard 2 button mouse • Frequently one can upgrade the mouse • 2 button with wheels • Optical Mouse.. no trackballs! • Wireless Mouse …no tail! \$200

23. When buying peripherals such as a mouse consider the type of connections available on your system.. And the price! PS2 Connection Newer Technology – faster than a Serial Serial Connection Oldest Technology - slow USB Connection Newest Technology - fastest

24. The monitor \$200 - \$2000+ Most systems do not come standard with a monitor unless buying a “complete package”. Consider the following when selecting a computer: • Size 17", 19" or 21" screen sizes • Monitor type • CRT bigger but cheaper, • LCD Display - Smaller but more expensive • Dot/Stripe Pitch - The smaller the Dot Pitch the sharper the image • Resolution – number of pixels that can be displayed – usually higher resolution gives a clearer image To go with your fancy new monitor you’ll need a video card that is compatible

25. Speakers \$20 - \$200+ Your new computer system may or may not come with other peripheral devices including Speakers and sound cards • Speakers vary based on Appearance, Subwoofer, 3D-sound • Sound Cards provide interface between the speakers & computer

26. Black & White Color Printers \$50 - \$10,000+ Unless your purchasing a “complete package” your system will probably not come with a printer. The two most common printer types are: • Laser Jet - faster, quieter. Can be single or duplex (print both sides), different sizes, multiple trays etc. • Inkjet - cheaper Its not always with printer that gets you.. It’s the price of the ink supplies!

27. Desktop Easy to use at a desk – larger keyboard Least expensive and available with greatest speeds & memory Laptop Portable More expensive than a desktop Keyboard, mouse -not quite as easy to use A desktop, a laptop, a tablet PC? Tablet • Great for taking notes & keeping ad-hoc records • Portable – able to take it with you • Most expensive & slower than std. computers \$300+ incl. monitor \$500+ \$1800+

28. Getting On-line • To get on-line you will need several items: • An Internet Service Provider (ISP) • Method of connecting • Telephone with modem (56K) • DSL – existing phone line but faster • ISDN – digital phone line • Cable – co-axial cable • Hardware • Modem – translate computer data to a “signal” • Communications/Network Card • Port • Ethernet Jack – use with cable modems • Phone Jack – use with telephone modems

29. The simplest communication is transmission of data over a communication channel between two computers • A modem (modulator/demodulator) connects your computer to the Internet by modulating the digital signal from the computer to a carrier signal Computer <--> Modem • Transmission Media <--> Modem <--> Computer

30. Networking - connecting a group of computers together • LAN - local area network • WAN - wide area network • Internet – network of networks

31. And what about security? Virus Protection – get Anti-virus software and keep it up to date Firewall – Software/Hardware that denies entry to all incoming traffic except those specifically requested or allowed Spam Filters – Available on most email packages or by providers and can be “customized” http://www.racecomputers.com/images/security_attack.jpg

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