CSC 102: Chapter 1

gigabyte

1 billion bytes

megabyte

1 million bytes

terabyte

1 trillion bytes

What are the major hardware components?

1. Cpu 2. Main memory 3. Storage devices 4. Input devices 5. Output devices 6. Communication devices (modem, nic)

Name 3 main types of storage devices:

1. Magnetic disk drives 2. Optical disk drives (cd, dvd) 3. USB flash drives

What are the major tasks of an operating system?

1. controlling and monitoring system activities; 2. allocating and assigning system resources; 3. scheduling operations

kilobyte

1000 bytes

central processing unit

CPU: the computer's brain; executes commands from a computer's hardware and software; the principal computer chip that contains several processing components, which determines the computer's operating speed; the "brain" of a computer

digital subscriber line

DSL, uses a phone line but can transfer data 20 times faster than a standard dial-up modem

Hypertext Markup Language

HTML, a simple scripting language for laying out documents, linking documents on the internet, and bringing images, sound and video alive on the Web

JDK

Java Development Toolkit. Consists of a set of separate programs, each invoked from a command line, for developing and testing Java programs

Who invented Java? Which company owns Java now?

Java was developed by a team led by James Gosling at Sun Microsystems. Sun Microsystems was then purchased by Oracle in 2010.

local area network

LAN commonly used in universities, businesses and government agencies.

network interface card

NIC, is a device that connects a computer to a local area network LAN. A high speed NIC called 1000BaseT can transfer data at 1,000 million bits per second (mbps)

random access memory

RAM, electronic circuits in a computer that can store code and data of running programs. random access is the ability to access any value directly without having to read the values preceding it.

rich Internet application

RIA, a Web application designed to deliver the same features and functions normally associated with desktop applications

ROM

Read only memory

universal serial bus

USB, connector allows user to attach many kinds of peripheral devices to the computer

motherboard

a circuit case that connects all of the parts of the computer together

line comment

a comment on a line preceded by two //

string

a programming term meaning a sequence of characters and must be enclosed in double quotation marks

encoding scheme

a set of rules that govern how a computer translates characters, numbers and symbols into data the computer can actually work with; example: ASCII encoding scheme

multithreading

allows a single program to execute multiple tasks at the same time, such as saving and editing a file

multiprogramming

allows multiple programs to run simultaneously by sharing same CPU

API

application program interface, also known as library, contains predefined classes and interfaces for developing Java programs

high-level language

began in 1950s, they are platform independent and can be run in different types of machines, they are English like and easy to read

bits

binary digits in the number system, 1s and 0s as on and off

speed

clock speed, measured in hertz, which enables computer to conduct operations at a specific speed

block comment or paragraph comment

comment enclosed by /* and */ on one or several lines

input devices

communicate with computer such as a mouse or keyboard

output devices

communicate with user such as monitors and printers

machine language

computer's native language which is a set of built in primitive instructions; very difficult to read and modify

memory

consists of an ordered sequence of bytes for storing programs and data the program is working with

assembly language

created in early days of computing as an alternative to machine language, uses short descriptive words known as mnemonics to represent instructions

drive

device for operating a medium, such as disks and CDs

USB flash drive

device for storing and transporting data

comment

documents what the program is and how it is constructed. The help programmers to communicate and understand the program. They are not statements and are ignored by the compiler.

applet

employ a modern graphical interface with buttons, text fields, text areas, radio buttons, and so on, to interact with users on the web and process their requests

unique address

every byte in memory has a unique address, used to locate the byte for storing and retrieving data

statement terminator

every statement in Java ends with a semicolon

reserved words or keywords

have a specific meaning to the compiler and cannot be used for other purposes in the program, such as class, public, static, void.

statements

instructions in high-level language

IDE

integrated development environment. java development tool for developing Java programs such as NetBeans, Eclipse, and TextPad.

computer program

known as software, are instructions that tell a computer what to do

low-level language

language close in nature to machine language, such as assembly language, and is machine dependent

function keys

located at top of keyboard and prefaced with letter F, they are software dependent

byte

minimum storage unit; composed of 8 bits

modifier key

modifies normal action of a key such as Ctrl, Alt, and Shift keys

modem

modulator/ demodulator, communication device used to network

console

old computer term that refers to the text entry and display device of a computer

control unit

one part of CPU, controls and coordinates actions of the other components

arithmetic/ logic unit

one part of CPU; performs numeric operations and logical operations

source program

or source code, program written in high-level language

block

pair of curly braces { } that groups a program's components. Such as class block and method block.

core

part of the processor that performs reading and executing of instructions; more cores= faster performance

pixel

picture element, are tiny dots that form an image on the display device

interpreter

reads one statement from source code, translates it to machine code or virtual machine code, and then executes it right away

screen resolution

specifies number of pixels in horizontal and vertical dimensions of the display device; the higher the resolution the sharper the display

Java language specification

technical definition of the Java programming language's syntax and semantics

dot pitch

the amount of space between pixels, measured in millimeters; the smaller the dot pitch, the sharper the display

software

the invisible instructions that control the hardware and make it perform a task

hardware

the visible, physical elements of the computer

transistors

tiny electric switches on a small silicon semiconductor chip for processing information; a device that acts as an electronic switch in complex circuits and is used to amplify signals; invented in 1947, it helped revolutionize society

compiler

translates entire source code into a machine-code file, which is then executed

hard disk drive

used for permanently storing data and programs, a computer usually has at least one

assembler

used to translate assembly language programs into machine code so compute can execute

dial-up modem

uses a phone line and can transfer data at a speed up to 56,000 bps (bits per second)

cable modem

uses cable TV line maintained by cable company and is generally faster than DSL

multiprocessing, or parallel processing

uses two or more processors together to perform subtasks concurrently and then combine solutions of the subtasks to obtain solution for entire task.