COMPUTER TECHNOLOGY

• What is a Computer?– An electronic device that can store, retrieve, and

process data..– Not smarter than people (only as smart as the person

who made it)– they are able to do calculations much faster than

humans can.

• Jay Forrester

PARTS OF A COMPUTER• Input Units: feeds information (data, images, and/or sounds) into the

computer.– Keyboard

– Mouse

– Voice Recognition

– Touch Screen

• Central Processing Unit (CPU): the microprocessor; CPU receives instructions, analyzes the input data, executes the necessary operations, and sends the information to storage.

• Memory or Storage Units: help the computer remember instructions and information. Consists of:– Internal Memory: Can be found within the CPU.

• Read-Only Memory (ROM): helps the computer remember which steps in the instructions come first.

• Random Access Memory (RAM): remembers what you tell the computer to do while the computer is on.

PARTS OF A COMPUTER (cont’d)• Internal Hard Disk Drive: stores data using electromagnetism (magnetism

caused by electricity).

– External Memory: memory units found outside the CPU.• DVD/CD Drive: uses CD-ROM (Compact Disc-Read Only Memory)

technology to store large amounts of information for the computer to access. For CD’s, a laser burns tiny pits into the surface of the disc , which form a binary code. When the disc is played, another laser reads the reflected light from these pits and sends the information to the CPU (CD’s are called Optical Storage Media because they use light to write and read the data).

Output Units: decode information or convert it into a language that humans can understand.

– Monitor

– Printer

– Speaker

• Some units (such as a modem) can be both input and output devices, meaning it can both feed information to and send information from your CPU.

COMPUTER LANGUAGES• Computers need a language so they can understand instructions

and carry out necessary operations. Programming languages translate inputs into a special machine language, which is finally changed into electrical impulses the CPU can understand)– Programming Language: developed to make writing programs easier.

The computers then translate these languages and obey the commands. Some examples:

• JAVA, HTML, BASIC, FORTRAM, C++, APL, PASCAL, RPG

– Machine Languages: made up of 2 signals – On (1) and Off (0). Every computer instruction, or bit, is made up of a series of 1s and 0s. The sequence of 1s and 0s is the machine language known as binary code.

COMPUTER LANGUAGES (cont’d)– Electrical Signals: info. must be changed into binary code so the

CPU can understand it; code enters the CPU as electric pulses; turn tiny electronic switches on (1) and Off (0); creates different combinations of paths for the electricity to follow.

– Each on or off pulse of the code is called a bit. Most machines combine eight bits into a byte.

• Analog Signal: infinite levels or variations & are continuous; sine waves such as speed, voice levels, and light intensity

• Digital Signals: CPU’s cannot understand analog signals (too many variations); they use digital signals -- discrete and have a finite number of levels; digital signals are either completely on or completely off – there is no in-between.

INTEGRATED CIRCUITS• Integrated Circuits (IC’s): also called microchips or chips; a tiny

piece of silicon with thousands of interconnected electrical circuits that work together.

• Transistors ; the main electronic part of the IC; a miniature electronic switch that cycles on and off to process information using binary code.

• IC’s – the basis of every communication tool we use; allow electrical impulses to pass through a circuit; carry a great deal of information & take up very little space.

HOW MICROPROCESSORS WORK

• The microprocessor goes through a 3 step sequence in order to make the computer work:

– Fetch: gets the instruction from computers memory or storage device.

– Decode: figures out what the instruction is.– Execute: carries out the instruction

SENDING & ALTERING INFO.• Altering Information: info. reduced to binary code, is easy to

manipulate. Are there any ethical concerns with the ability to manipulate words or pictures?

• Sending Voices: “voices” you hear on a phone are not really voices – they are re-creations of the electrical pulses that were sent through the series of IC’s to the earpiece

• Sending Images: can change words and pictures into digital information and send it by fax machine, e-mail, etc..

• Retrieving Information: Can either be done from a data bank (a large computer that stores the information from several smaller computers) or can be done using WAN or LAN computers.

• Bar Codes: a striped code printed on almost every product sold in the United States. The code is scanned by a special laser, which reads the product name, its price, where it was sold, on what day, etc… All the information is sent electronically to a central data bank

INTERNET & ON-LINE SERVICES• The Internet – a noncommercial, computer network that can be

accessed with the right hardware & software. • The World Wide Web (WWW) -- written using Hypertext Markup

Language (HTML)• The WWW is like a very large library; each individual website is like

an individual book on a shelf.• Each website has a specific address or Universal/Uniform

Resource Locator (URL) – like the address of your house• A web browser -- a computer software product that helps you

access and use the internet (Internet Explorer, Safari, Mozilla)• An ISP (Internet Service Provider) – a company (such as AOL,

Comcast, Bellsouth) that gives you both the hardware & software necessary to access the Internet.

• A search engine – a website (such as Google, Bing, or Yahoo) that helps you search the Internet for specific information on a specific subject

INTERNET & ON-LINE SERVICES• Chat rooms and video conferencing make long-distance education

possible (Skype)• The Internet makes e-mail possible by using specific software

programs and the existing Internet infrastructure

ARTIFICIAL INTELLIGENCE• Artificial Intelligence (AI) – the process computers use to solve

problems and make decisions commonly solved by humans.• Expert Systems: program has all available facts about topic;

computer uses this expert system to perform a variety of functions, ranging from system diagnosis to chemotherapy, to communication.

• Speech Recognition: Speech recognition; software program used with certain hardware; used to recognize a “persons” voice; Apple’s Siri, “O.K. Google”

• Virtual Reality: 3D systems that attempt to replicate real-life