Introduction to Personal Computers

1. Introduction to Personal Computers Hardware Thanks to Chris Wright and Don Campbell for the content of this presentation!

2. What Are Computers For? • Create Documents • Create Presentations • Process Business Transactions • Perform analysis Many Uses Bottom Line: Computers are tools that allow users to increase their productivity.

3. What Does A Computers Do? • Input • Processing • Output

4. Bits & Bytes • Bit (a zero or 1) • Eight Bits = One Byte • One Byte = One Character • One KB = 1,024 Bytes {1 Thousand} • One MB = 1,024,000 Bytes {1 Million} • One GB = 1,024,000,000 Bytes {1 Billion} • One TB = 1,024,000,000,000 Bytes {1 Trillion} • Remember Processing takes place one byte at a time

5. Personal Computer History • IBM offered PC in 1981 • Intel designed microprocessor for IBM platform • Microsoft designed operating system • Open design created IBM PC Compatible market • Apple – forced PCs to become more user-friendly.

6. What’s In a Computer? • Microprocessor (CPU) • Internal Memory • Auxiliary Storage • Input Units • Output Units

7. The Microprocessor (CPU) • The ‘brains’ of any computer • Central Processing Unit • Where most computations take place • Made up of two main components: • Arithmetic Logic Unit{which performs arithmetic and logical operations} • Control Unit{extracts instructions from memory, decodes & executes them, calls on the ALU when necessary} • Performance is measured by clock speed; how quickly the CPU ‘cycles’ each second • Megahertz • Gigahertz

8. CPU Performance • Performance is measured by clock speed; how quickly the CPU ‘cycles’ each second • One MHz = 1 million cycles per second • One Gigahertz = 1 billion cycles per second • Indicates number of instructions the computer can handle per second • Data Bus Width • Number of bits that can be transferred at one time • 64 Bit Bus can handle 64 bits per cycle

9. History of CPUs • 8086 / 8088 (1981) – 8 Megahertz • 80286 {286} • 80386 {386} • 80486 {486} • Pentium {586} • Pentium II • Pentium III • Pentium IV (2001) – 2 Gigahertz

10. Processor Performance

11. Main Memory • Memory - temporary, fast storage area that holds data, instructions, and results, and passes everything to the CPU • Random Access Memory {Temporary Storage} • DRAM {Dynamic, less expensive, more common} • SRAM {Static} • Volatile • Can be found in Printers or other devices • Needs refreshing 1,000’s of times/second

12. ROM • Read Only Memory – like RAM, but static • Data is prerecorded • Data can not be altered, only read • Nonvolatile • Contains the instructions a computer need to boot (Basic Input Output System) • Can be found in printers or other devices • PROM (programmable), EPROM (erasable, programmable)

13. Auxiliary Storage • Permanent storage of data/programs • Types includes • Hard disk = Fixed Disk • Gigabyte ~ 1 billion bytes • Access Time – not as fast as memory (which is 100 times faster) • Today – cheap ($200-$300 for 40GB drive) • Floppy disks • High Density = 1.44MB • Removable Disks • CD ROM (650 MB) • DVD • Second Hard Disk • Zip/Jazz (100MB to 1 GB) • Tape (Sequential storage) – typically used for backups

14. Internet Connections • Modem • Modulate • Demodulate • Bit = binary digit • bps = bits per second • Fax/modem card • Recommendation: Buy at least 56K, High Speed Internet or Cable

15. Multimedia • CD-ROM Compact Disk, Read Only Memory • DVD • Sound card needed for microphone and speakers

16. CD-ROM CPU Expansion slots Floppy drive Hard disk Memory chip Motherboard Power supply Inside the Computer

17. Motherboard • The main circuit board • Contains the CPU, BIOS, memory, expansion slots, ports, etc.

18. Keyboard Mouse Scanner Trackball Joystick Pens Input Devices

19. Output - Monitors • Output device • Types • Size • Pixel • Resolution • Dot pitch • Refresh rate • Interlaced / non-interlaced • Multi-scanning

20. Monitor Types • Monochrome • One colour on black - old technology • Colour • CGA • Colour Graphics Adapter - old technology - introduced in 1981 by IBM - could produce only 2 colours at a resolution of 640 x 200 - poor quality image - now obsolete • EGA • Enhanced Graphics Adapter - old technology - introduced in 1984 by IBM - could produce 16 colours at a resolution of 640 x 350 - better than CGA but still poor quality image - now obsolete • VGA • Video Graphics Array - newer technology - introduced in 1987 by IBM - can produce 262,144 colours - resolution of up to 720 x 400 - All PC’s today support VGA • SVGA • Super Video Graphics Array - new technology - can produce 16,000,000 colours - resolution of up to 1600 x 1200 • Touch screen • A type of display screen that has a touch-sensitive transparent panel covering the screen. Instead of using a pointing device such as a mouse or light pen, you can use your finger to point directly to objects on the screen

21. Size • Typical sizes are 14” - 15” - 17” - 19” - 21” • Measured diagonally • Pixel {short for picture element - smallest dot of light that a monitor can display} • Dot Pitch {measured in millimeters - it is the distance between each pixel - usually between .15mm to .30mm} • Resolution {the number of pixels on the entire screen - for example a monitor with a resolution of 640 x 480 is capable of displaying 640 dots on each of 480 lines on the screen}

22. Printers • Output device • Quality • Speed • Impact / Non-impact • Types

23. Types of Printers • Daisy Wheel • Dot Matrix • Ink Jet / Bubble Jet • Thermal • Line • LCD & LED • Laser • Plotter

24. Daisy Wheel Printer • Impact, letter quality • Similar to a ball-head typewriter • A hammer presses the wheel against a ribbon, which in turn makes an ink stain in the shape of the character on the paper. • Cannot print graphics • Uses a ribbon • Speed measured in CPS {Characters Per Second}

25. Dot Matrix Printer • Impact, near letter quality • Uses a ribbon • Comes in 9 Pin or 24 Pin • One character at a time • Speed measured in CPS • Noisy • Great for multiple part forms Creates characters by striking pins against a ribbon onto the paper

26. Ink-Jet Printer • Non-impact, letter quality • Sprays ink on paper • Colour • Uses ink cartridges • One line at a time • Can be very slow when high quality is desired

27. Line Printer • Impact, near letter quality • High speed - up to 3,000 lines per minute • Cannot print graphics • Very noisy

28. Thermal Printer • Non-impact, letter quality • Uses heat to transfer an impression onto paper • Used in early fax machines • Often found at retail outlets in the form of a receipt

29. Laser Printer • Non-impact, letter quality • Uses toner • Full page printer • Speed measured in PPM {Page Per Minute}

30. Plotter • Not really a printer • Draws pictures on paper based on commands from a computer • Continuous lines • Uses pen(s) • Normally used in engineering applications

31. Main Components 1Gb microprocessor 256Mb RAM 30Gb hard drive 1 floppy drive Zip drive DVD or CD-ROM drive 19” monitor * 64Mb graphics card Other Components HS Internet / Cable modem CD-RW drive Sound card/speakers Camera Microphone TV adapter The PC Today

32. Purchasing on the Web • www.dell.com • www.gateway.com • www.ibm.com • www.pcwarehouse.com • www.microwarehouse.com