Introduction to Computers

What is a computer?

An electronic device, operating under the control of instructions stored in its own memory unit, that can accept data, manipulate the data according to specified rules, produce information from the processing, and store the results for future use.

Devices that comprise a personal computer.

Inside a computer

Information Processing Cycle—four general operations Input Processing Output Storage

What are the components of the computer? Input devices Central processing unit (CPU) Output devices Memory Storage devices

Input Devices

Keyboard Mouse Digital camera Scanner Microphone

Keyboards

Mouse Devices

Digital Cameras

Scanners

Microphones

Central Processing Unit

Made up of the control unit and arithmetic/logic unit

The brains of the CPU is the processor. There are different brands and speeds Pentium made by Intel Celeron made by Intel Athlon made by AMD

Memory RAM—also called Random Access Memory

Processors & Memory

Data Representation Byte—one character of data Kilobyte—one thousand bytes of data Megabyte—one million bytes Gigabyte—one billion bytes Terabyte—one trillion bytes Petabyte—one quadrillion bytes Exabyte—one quintillion bytes Zettabyte—one sextillion bytes Yottabyte—one septillion byteshttp://www.jimloy.com/math/billion.htm

Output Devices Printers

Impact printers Dot matrix printers

Nonimpact printers Ink jet Laser

Color B & W

Monitors CRT’S LCD’S

STORAGE DEVICES Floppy Disks

3.5-inch disks store 1.44M of data Must be formatted

Tracks sectors

Hard Disks Spins at 5,400 – 7,200 rpm (revolutions per minute) Can store anywhere between 10G – 250G+ of data

CD’s—Compact Discs Available in a variety of formats—CD-ROM, CD-R, CD-RW A typical CD holds about 650 MB of data

DVD’s Available as DVD-ROM, DVD-R, DVD-RW Can hold 4.7 GB of data

Zip Drives—high capacity floppy disk drive; has lost popularity Zip disks can hold from 100 MB – 250 MB of data

USB Flash Drive Storage capacity between 32 MB – 4 GB

STORAGE DEVICES

Care and Handling of Storage Devices

Handling the CD / DVD / Blu-ray Disc™ media

Care and Handling of Storage Devices

Do not use solvents benzine thinner Alcohol commercially available

cleaners anti-static spray

For normal cleaning hold the disk by its

edges use a soft cloth to

wipe the surface from the center out.

For badly soiled disk moisten a soft cloth with

water, wring it out well, wipe the surface of the

disk from the center out wipe off any remaining

moisture with a dry soft cloth

Never affix an adhesive label to a disk.

Care and Handling of Storage Devices

Care and Handling of USB Port Drives –

More stable and reliable than floppy disks Treat with care and consideration USB port drives can only fit in the port one way! Keep the USB port drive cap/cover on the plug

end of the device whenever it is not in use.

Care and Handling of Storage Devices

Keep USB port drives away from liquids and excessive heat!

Once broken, data cannot be restored by software recovery tools or by lab instructors or staff.

They can be damaged by impact (being dropped, hit, etc.)