How Computers Work

All Computers process data

• 1-- Input data• 2--Store 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

• Mouse Scanner Camera

• Keyboard Drives Peripheral

• Touch Screen Microphone devices

All Computers have memoryRAM (Random Access Memory

Storage -- Hard Drive

Video Memory

All Computers have a CPU• 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

Computer Hardware (a machine)

Software(programs)

• Instructions that the computer needs to function the way we want it to

The number of apps available for download in leading app stores in July 2014. 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 2+2+2+2+2+2

Letters are converted to binary code through ASCII

American Standard Code for Information

letter Binary ASCII• J 01001010 74• I 01001001 73• M 01001101 77

• 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 Bytes

• 1BYTE is 8 Binary digits • 8 bit Units are called BYTES

Kilo – 1000 bytesMega – 1 million bytesGiga – 1 billion bytesTera – 1 trillion bytes

1 Petabyte - 1 quadrillion

2007: 1 terabyte hard disk costs US$375 2010: 2 terabyte hard disk costs US$200

2012: 4 terabyte hard disk US$450 (Hitachi, largest available in consumer market), 1 terabyte hard disk US$100

2013: 4 terabyte hard disk US$179, 3 terabyte hard disk $129, 2 terabyte hard disk $100, 1 terabyte hard disk US$80

2014: 4 terabyte hard disk US$150, 3 terabyte hard disk $129, 2 terabyte hard disk $90, 1 terabyte hard disk US$60