How Computers Work

All Computers process data process data 1-- Input dataInput data 2--Store data while being processedStore data while being processed 3--Process the data according to specific instructions 4--Output the results in the form of new data

All Computers Process Data According to specific instructions -- Those instructions are entered through INPUT DEVICES MouseScannerCamera KeyboardDrivesPeripheral Touch ScreenMicrophonedevices

All Computers have memorymemory RAM (Random Access Memory Storage -- Hard Drive Video Memory

All Computers have a CPUCPU The CPU is the Central Processing Unit It is the equivalent of the human brain for a computer It processes data (input) and makes decisions based on instructions in the programs

ComputerComputer Hardware (a machine)Hardware

Software (programs) Instructions that the computer needs to function the way we want it toInstructions The number of apps available for download in leading app stores in July As of that month, Android users were able to choose between 1.3 million apps. Apple's App Store remained the second-largest app store with 1.2 million available apps.

Computer Memory ROM -- Read Only Memory. Memory that is “burned” on the chip for basic instructions for the computer to start up. PERMANENT Part of the computer that you normally don’t change factory settings

RAM MEMORY RANDOM ACCESS MEMORY Temporary memory where data and instructions are stored. Programs require RAM to operate. When machine is turned off, what is in RAM is LOST. RAM is VERY Important when purchasing a computer. Standards are 6-8 gb for laptops-desktops

CPU Central Processing Unit It directs all the activities of the computer. It follows the directions contained in ROM or from a program that is operating in RAM It adds numbers and compares numbers very very quickly. The primary components are aluminum, copper and (a hard plastic silicon) Covered circuits are etched on the CPU These circuits conduct electricity Electrical circuits have one of 2 states ON or OFF

0 = OFF 1 = ON Number system that uses only 2 numbers is called a BINARY system. Adds and compares numbers 5X2 is Letters are converted to binary code through ASCII American Standard Code for Information

letter Binary ASCII J I M Every 0 or 1 in the binary code is called BIT (Binary Digit). These are grouped together by the computer into 8 bit units called BytesEvery 0 or 1 1BYTE is 8 Binary digitsBYTE is 8 Binary digits 8 bit Units are called BYTES

Kilo – 1000 bytes Mega – 1 million bytes Giga – 1 billion bytes Tera – 1 trillion bytes 1 Petabyte - 1 quadrillion 2007: 1 terabyte hard disk costs US$ : 2 terabyte hard disk costs US$ : 4 terabyte hard disk US$450 (Hitachi, largest available in consumer market), 1 terabyte hard disk US$ : 4 terabyte hard disk US$179, 3 terabyte hard disk $129, 2 terabyte hard disk $100, 1 terabyte hard disk US$ : 4 terabyte hard disk US$150, 3 terabyte hard disk $129, 2 terabyte hard disk $90, 1 terabyte hard disk US$60