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

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

What Does A Computers Do? Input Processing Output

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

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.

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

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

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

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

Processor Performance

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

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)

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

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

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

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

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

Input Devices Keyboard Mouse Scanner Trackball Joystick Pens

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

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 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 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 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

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}

Printers Output device Quality Speed Impact / Non- impact Types

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

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}

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

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

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

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

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

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

The PC Today 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

Purchasing on the Web