Computer Confluence 7/e © 2006 Prentice-Hall, Inc.

Computer Confluence 7/e Chapter 2 Hardware Basics: Inside the Box © 2006 Prentice-Hall, Inc.

Computer Confluence 7/e Chapter 2 Objectives How computers store and manipulate information The basic structure and organization of a computer The functions and interactions of a computer system ’ s principal internal components Types of memory and storage devices © 2006 Prentice-Hall, Inc.

Computer Confluence 7/e Chapter 2 What Computers Do Basic Functions of a Computer Receive input: Accept information from the outside world Process information: Perform arithmetic or logical (decision- making) operations on information Produce output: Communicate information to the outside world Store information: Move and store information in memory © 2006 Prentice-Hall, Inc.

Information Processing Cycle Steps followed to process data Input Processing Output Storage

Computer Confluence 7/e Chapter 2 What Computers Do (continued) Basic Components of a Computer Input devices: Accept input from the outside world  Keyboards and pointing devices (mouse) Output devices : send information to the outside world.  Display or video monitor  Printer  Speakers © 2006 Prentice-Hall, Inc.

Basic Components of a Computer Microprocessor or Central Processing Unit (CPU) The CPU Processes information, Perform arithmetic calculations, and makes logical (decision-making) operations on information.

Computer Confluence 7/e Chapter 2 What Computers Do (continued) Basic Components of a Computer Memory and storage devices both store information  Primary storage: RAM (Random Access Memory) is used to store programs and data that need to be instantly accessible to the CPU.  Secondary storage: Storage devices that serve as long-term repositories for data  Hard disk drives  Recordable CD and DVD drives  Tape drives © 2006 Prentice-Hall, Inc.

Computer Confluence 7/e Chapter 2 A Bit About Bits Information  Definition1: Communication that has value because it informs  Definition 2: Anything that can be communicated, whether it has value or not Information comes in many forms  Words, numbers, pictures  Sound, movies computers turn raw data (no value) into information (valuable). In computer terminology the terms data and information are more or less interchangeable © 2006 Prentice-Hall, Inc.

Computer Confluence 7/e Chapter 2 A Bit About Bits (continued) Computer ’ s information is digital made up of discrete, countable units – digits-  Bit, or binary digit  The smallest unit of information A computer can Process.  Can have one of two values: 1 or 0  Can represent numbers, codes, or instructions  Byte: a collection of 8 bits (can represent 256 different combination) © 2006 Prentice-Hall, Inc.

Computer Confluence 7/e Chapter 2 A Bit About Bits (continued) Using two symbols all numbers can be represented on a calculated as well as performing arithmetic A calculator translates the touch on the numeric keypad into series of 0s and 1s  Each number then is looked at as a component of its positional values (each a power of 2)  19 will be represented as © 2006 Prentice-Hall, Inc.

Computer Confluence 7/e Chapter 2 A Bit About Bits (continued) Bits as Numbers Binary number system  Denotes all numbers with combinations of two digits  Decimal numbers are automatically converted by software into binary numbers and vice versa  Binary number processing is completely hidden from the user © 2006 Prentice-Hall, Inc.

Computer Confluence 7/e Chapter 2 A Bit About Bits (continued) Bits as codes ASCII  Represents each character as a unique 8-bit code  The most widely used code  An abbreviation of American Standard Code for Information Interchange Unicode  Represents each character as a unique 16-bit code  A coding scheme that supports 65,000 unique characters © 2006 Prentice-Hall, Inc.

Computer Confluence 7/e Chapter 2 A Bit About Bits (continued) Bits as Instructions in Programs Programs stored as collections of bits  Program instructions represented in binary notation through the use of codes © 2006 Prentice-Hall, Inc.

Computer Confluence 7/e Chapter 2 A Bit About Bits (continued) Bits, Bytes, and Buzzwords Bit-related terminology © 2006 Prentice-Hall, Inc. –Byte –Kilobyte (KB) –Megabytes (MB) –Gigabytes (GB) –Terabytes (TB) –Petabyte (PB) = 8 bits = 1 Thousand Bytes(1024 byte) = 1 Million Bytes = 1 Billion Bytes = 1 Trillion Bytes = 1024 terabyte used to describe the capacity of memory and storage components.

Computer Confluence 7/e Chapter 2 Green Computing Manufacture of hardware and software can have an impact on the environment Buy green equipment (Energy Star) Use a Notebook & a solar battery  Use energy-saving features Turn off when you ’ re away Screen Savers don ’ t save energy Print only once Recycle waste products © 2006 Prentice-Hall, Inc.

Computer Confluence 7/e Chapter 2 The Computer ’ s Core: The CPU and Memory The CPU: The Real Computer The processor performs the transformation of input into output. CPU (microprocessor)  Interprets and executes the instructions in each program  Supervises arithmetic and logical data manipulations © 2006 Prentice-Hall, Inc.

Computer Confluence 7/e Chapter 2 The Computer ’ s Core: The CPU and Memory (continued) CC ommunicates with all the other parts of the computer system indirectly through memory CC PU is An extraordinarily complex collection of electronic circuits HH oused along with other chips and electronic components on t he motherboard © 2006 Prentice-Hall, Inc.

Computer Confluence 7/e Chapter 2 Compatibility All software is not necessarily compatible with every CPU Every processor has a built-in-instruction set.  Software written for the PowerPC family of processors used in Macintosh computers won ’ t run on Intel processors found in most IBM-compatible computers.  Programs written for Linux can ’ t run on Windows  Both systems run on PCs powered by Intel ’ s microprocessor  CPUs in the same product family are generally designed to be backward compatible  Newer processors can process all of the instructions handled by earlier models © 2006 Prentice-Hall, Inc.

Computer Confluence 7/e Chapter 2 Performance Some Applications such as graphic design, computer games require faster machines to produce satisfactory results A computer ’ s overall performance is determined by: 1.The speed of its microprocessor ’ s internal clock : the timing device that produces electrical pulses to synchronize the computers operations.  clock speed is Measured in units called gigahertz (GHz) : billions of clock cycles per second © 2006 Prentice-Hall, Inc.