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