WINDOWSPart 4 – Components of
Computers
A World of Computers• Computer Literacy
– Knowledge and understanding of computers and their uses
– Computers are everywhere
Computer Applications in Society• How are computers used in society?
Education Finance Government Health Care Science Publishing Travel Manufacturing
What Is a Computer?• Computer – an electronic device, operating
under the control of instructions stored in its own memory, that can:–process the data according to specified
rules (processor)–accept data (input)–produce results
(output)–store the results
(storage) for future use
What Does a Computer Do?• The four basic
operations compromise the Information Processing Cycle
Processor• Processor – interprets and carries out the
basic instructions that operate a computer–Called Central Processing Unit (CPU)–The brains of the computer–Measured in hertz
• Control Unit – interprets the instructions
• Arithmetic/Logic Unit – performs the logical and arithmetic processes
Units of Speed(characters processed per second)
• Hertz – approximately 1 character• Kilohertz – approximately 1,000 characters• Megahertz – approximately 1,000,000
characters (1 million)• Gigahertz – approximately 1,000,000,000
characters (1 billion)• Terahertz – approximately 1,000,000,000,000
characters (1 trillion)
Memory• Memory – consists of electronic
components that store data, instructions, and information, as needed by the processor– Measured in bytes– RAM – Random Access Memory
• Holds the instructions, programs, information you input
• Will be lost if not saved (Measured in bytes)– ROM – Read Only Memory
• Can be read but not modified (system files)
Units of Memory• Byte – approximately 1 character• Kilobyte – approximately 1,000 characters• Megabyte – approximately 1,000,000
characters (1 million)• Gigabyte – approximately 1,000,000,000
characters (1 billion)• Terabyte – approximately
1,000,000,000,000 characters (1 trillion)
Storage Devices
• Used to store instructions, data, and information when they are not being used in memory
Magnetic Disks• Magnetic disks
use magnetic particles to store items on a disk’s surface– Floppy disks– Zip disks– Hard disks
Optical Discs• Optical discs
– CD-ROM– CD-R– CD-RW– DVD-ROM– DVD-R– DVD+R– DVD-RW– DVD+RW– DVD+RAM
• Tape
Miniature MobileStorage• Miniature mobile storage
media
Flash Drives
• Small, removable storage devices that range from 64 MB to 64 GB
• Integrated with a USB interface
System Unit
• The processor, memory & storage devices are housed in a box-like case called the system unit
Input Devices• Any hardware component that allows you
to enter data, programs, commands, and user responses into a computer
• Input Device Examples:– Keyboard– Mouse– Web Cam– Scanner– Camera
Output Devices• Output devices make the information
resulting from processing available for use• Output Device Examples
– Printers (dpi/ppm)• Impact (dot matrix)• Photo
(inkjet/bubble jet) • Nonimpact (laser)
– Display Devices• CRT• LCD
Components of a Computer
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