Computer Science

Information Literacy

knowing how to find; analyze; and use information

Computer Literacy

knowing how to use a computer

Monitor

one of three commonly used output devices

Data

raw facts given to a computer during the input operation

Information

input that has been processed into a meaningful and useful form

Laptop Computers

larger versions of notebook computers that weigh between eight and fifteen pounds

Mainframe Computers

large systems that usually require a specialized environment

Supercomputers

the most powerful and most expensive category of computers

Systems Analyst

together with the user and programmer; determines and designs desired program output

Computer Programmer

writes the instructions necessary to direct the computer to process data into information

System Software

programs related to controlling the actual operation of computer equipment

Operating System

an important part of system software that tells the computer how to perform functions such as load; store; and execute a program

Graphical User Interface (GUI)

part of an operating environment that provides visual clues to help the user

Icon

a graphical image in a user interface that represents an application software package; file; or document

Information System

consists of hardware; software; users; personnel; data; and procedures

Application Software

programs that tell a computer how to produce information

Central Processing Unit (CPU)

contains a control unit and an arithmetic/logic unit (ALU)

Control Unit

the component of the CPU that directs and coordinates most of the operations in the computer

Arithmetic/Logic Unit (ALU)

performs execution part of the hardware cycle including comparisons of data

Secondary Storage Devices

devices used to permanently store data and program instructions when they are not being processed

System Unit

the main case of a computer containing the electronic circuits that actually cause the processing of data to occur

Connectivity

refers to the ability to connect a computer to other computers

Procedures

the element of an information system that documents computer operations and related operations to help the system run efficiently

Workstations

expensive; high-end personal computers with powerful calculating and graphics capabilities frequently used by engineers

Minicomputers

computers more powerful than personal computers that can support a number of users performing different tasks and cost from $15000 to several hundred thousand dollars

Desktop Computers

the most common type of personal computer designed to fit conveniently on the surface of a workspace

The central processing unit (CPU)

contains the control unit and the arithmetic/logic unit

Level 2 (L2) cache

cache that is not part of the CPU chip

Connectors

different types of couplers on ports used to attach cables to peripheral devices

Power supply

converts the wall outlet electricity to the lower voltages used by the computer

Parallel processors

require special software that can recognize how to divide up problems and bring results back together again

Silicon crystals

the most common raw material used to make chips

Analog computers

systems designed to process continuously variable data

Parity bit

extra bit used by the computer for error checking

Machine cycle

the four-step process of fetching decoding executing and storing

Cache memory

high-speed RAM memory between the CPU and the main RAM memory

CMOS

memory that stores information about the computer system

Bus

any path along which bits are transmitted

Serial port

interface that transmits data one bit at a time

Instruction set

contains commands that the computer's circuits can directly perform

Massively parallel processors

systems that use hundreds of thousands of microprocessor CPUs to perform calculations

Hexadecimal

base 16 number system commonly used with computers

Byte

a group of eight bits that can represent 256 different data possibilities

EBCDIC

coding system used primarily on mainframe computers

Motherboard

a circuit board that contains most of the electronic components of the system unit

Decoding

the operation in the machine cycle where program instructions are translated into commands

Startup instructions

data used when a computer is first turned on which is not stored in RAM

Parallel ports

interfaces often used to connect printers or disk and tape drives

Bay

an open area inside the system unit used to install additional equipment

Operation code

the part of a machine language instruction that tells the computer what to do

Pipelining

efficiency method where a new instruction is started as soon as the preceding instruction moves to the next stage

Binary 1011

representation for the decimal quantity 11

Digitizing

converting data into digital form

ASCII

the coding system used most widely on personal computers and minicomputers

Even parity

an error checking method where the total number of on bits must be a number divisible by 2

System unit

the main chassis including the motherboard microprocessor CPU memory ports connectors and power supply

Storing

the machine cycle operation that takes place when the result of the instruction is written to memory

Word size

the number of bits the CPU processes at one time

Non-volatile

description for memory like ROM because it retains its contents even when the power is turned off

SCSI port

a special type of parallel port that can be used to attach seven to fifteen different devices to a single port

RISC

CPU technology that involves reducing the instructions in the instruction set to only those most frequently used

Wafers

thin slices of smoothed silicon ingot into which chips are sliced

Bit

a single off or on digital value representing the smallest unit of data handled by a computer

Control unit

component contained in the CPU which can be thought of as the brain of the computer

Fetching

the operation in the machine cycle that means obtaining the next program instruction from memory

Port

a socket used to connect the system unit to a peripheral device such as a printer or a modem

Digital computers

computers that process data by first converting text sound graphics or video into a numeric value

Unicode

a 16-bit code that has the capacity to represent more than 65000 characters and symbols

Flash RAM

a relatively new type of memory that can retain data even when the power is turned off

System unit

contains the central processing unit or CPU

Binary 0

used to represent the electronic state of off

ASCII and EBCDIC

two widely used codes that represent characters in a computer

Microprocessor

one of the main components on the motherboard

Machine cycle

the process that contains fetching decoding executing and storing

Word size

the number of bits the CPU can process or manipulate at one time

Memory chips

components installed on circuit boards that control computer devices

Gigabyte

equal to approximately one billion bytes

Volatile memory

description for RAM because programs and data are lost when power is turned off

SIMM

a small circuit board that has multiple RAM chips on one side

Millisecond

one thousandth of a second

Buses

pathways used to transfer bits from input devices to memory

Expansion board

circuit board for an add-on device that adds capability to a computer system

PC Card

credit card sized device used to add memory storage or communications capabilities

Ports

interfaces found on the front or back of the system unit used to attach cables

MIDI

special type of serial port designed to be connected to a musical device

Machine language instruction

the only form of program instructions that the CPU can directly understand

Parallel processing

capability where a CPU processes multiple instructions at a time

Binary number system

a system where each position has a place value associated with it

Clean rooms

highly controlled environments where computer chips are manufactured

System unit

the specific term used to describe the chassis because this is where computing actually happens

Binary digits

values 0 and 1 used because they can easily be represented electronically by circuits

EBCDIC

character coding system used primarily on mainframe computers

Two bytes

the equivalent capacity of a 16-bit word size

Sockets

type of receptacle on some motherboards used for microprocessors

RAM contents

stores operating systems application instructions and data currently being processed

Byte

basic unit of memory consisting of 8 bits

Nonvolatile

description for ROM because it retains its contents even when the power is turned off

Decimal 9

quantity represented by binary 1001

Serial or parallel

the two primary formats that ports can use

Memory address

a number that indicates the precise location of a byte in memory