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 bytes

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 Do not touch the surface of the disk. Fingerprints and dust on the surface of a disk may cause read errors. Always hold the disc by its edges and central hole, as shown: 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.)