Computer Hardware The insides and outsides of my computer.

Hardware vs. Software Hardware  Physical components  Input/Output devices  Internal components Software  The programs or instructions that tell the computer what to do  Operating systems  Applications  Programs

Operating System  Windows  XP, Vista, 7  Server 2003, 2008  Mac OS X  Unix  Linux – Red Hat, Debian, Ubuntu, etc

Application Software  Microsoft Office Suite  Word, PowerPoint, Excel, Access, Outlook, Publisher  Computer Games  Pinball, Solitaire, Free Cell  Internet Browsers  Internet Explorer, Firefox, Chrome  Picture editing software  Paint, Photoshop

Form Factor  Desktop  Laptop  Netbook  Tablet

Input/Output Devices

Input Devices  Mouse  Keyboard/Keypad  Game Controller  Webcam  Microphone  Touchscreen  Scanner

Output Devices  Monitor  Printer  Touchscreen  Projector  Speakers  Headphones

Now let’s go inside…

The Tower The tower is the enclosure that contains the main components of a computer.

Inside the Computer ü Motherboard (main board) – Large printed circuit board with thousands of electrical circuits. ü Power supply – Transforms alternating current (AC) from wall outlets to direct current (DC) needed by the computer. ü Cooling fans – Circulates air in the system unit to keep it cool ü Internal speaker – Found on the motherboard and used by the operating system for diagnostics and error reporting—the beeps and other mono-tones. Not responsible for playing music, etc. ü Central Processing Unit - A microprocessor that interprets and carries out instructions given by software. It controls the computer’s components. It is covered by the heat sink, which serves to keep it cool. ü Storage – Hard drive, RAM, and secondary storage. ü Graphics and Sound Cards – Expansion cards placed in ports on the motherboard to improve graphic and audio output.

The Motherboard  The motherboard provides the centralized connection point for the computer’s components  Electrical traces (wires) on the motherboard connect to the chips.  Sockets allow chips or circuit boards to be added or devices to be connected to the motherboard.

Power Supply and Cooling Fan  The power supply is used to give power to all the hardware components on your computer system.  The computer takes energy from your home electrical system and converts 110 to 120 bolts AC power to lower DC voltages.  The power supply contains one of the cooling fans that keep the inside of the computer case cool.

The Central Processing Unit: The Microprocessor CPU CPU socket  Central processing unit ( CPU ) – A microprocessor that interprets and carries out instructions given by software. It controls the computer’s components.

Memory Random Access Memory (RAM)  Memory is the term used to describe devices that enable the computer to retain information. Program instructions and data are stored in memory chips for quick access by the CPU. Read-Only Memory (ROM) Flash Memory Blue Ray and commercial music CD

ROMRAM How ROM and RAM work… CPU

Random Access Memory (RAM) ü Random Access Memory (RAM) is a type of memory that stores information temporarily so that it’s available to the CPU. ü The more programs open, the slower the computer runs because more RAM is being used and less is available. ü RAM is volatile; the memory’s contents are erased when the power is turned off. ü Laptops in standby mode keep power to the RAM so the laptop can wakeup and be ready to go without having to boot and load the operating system.

Random Access Memory (RAM)  The computer loads the operating system (OS) from the hard drive into the system's random access memory (RAM).  Generally, the critical parts of the operating system are maintained in RAM as long as the computer is on. This allows the CPU to have immediate access to the operating system, which enhances the performance and functionality of the overall system  When you open an application, it is loaded into RAM. To conserve RAM usage, many applications load only the essential parts of the program initially and then load other pieces as needed.  When you save a file and close the application, the file is written to the specified storage device, and then it and the application are purged (deleted) from RAM.

Read-Only Memory (ROM)  When you turn on the computer it loads up from read-only memory (ROM). “A computer memory that does not need to be changed, such as permanent parts of the operating system.” Dictionary of Computer and Internet Terms (ninth edition) by Douglas Downing, Ph.D.  Compact Disk Read-Only Memory = CD-ROM An optical disk containing computer data (like an audio compact disk). CD-ROM s can only be read not recorded on. Dictionary of Computer and Internet Terms (ninth edition) by Douglas Downing, Ph.D.

Hard Drive  The Hard Drive is the main storage component on your computer that holds your data files.  These files include the data used to start your operating system. A hard drive consists of round platters made of aluminum, ceramic or glass.  The platters are coated with an alloy material which read/writes record information on magnetically

Secondary Storage  Hard Drive (external/internal)  Writable CD-ROMs and DVDs  Flash memory

Need for Secondary Storage Devices  Primary memory is volatile memory – lose electrical power and this memory loses its contents.  Secondary storage stores data on permanent media that maintain their accuracy and integrity, yet permit access.

Secondary Storage Devices  Which of these devices is capable of storing the most data? a.CD-ROM disk b.DVD disk c.USB (flash memory) drive d.External hard drive

Secondary Storage Devices  d. External Hard Drive holds the most data.

Storage Speed