Computer HardwareThe insides and outsides of my computer.

Hardware vs. SoftwareHardware

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

Inside the Computer Motherboard (main board) – Large printed circuit board with

thousands of electrical circuits. Power supply – Transforms alternating current (AC) from wall

outlets to direct current (DC) needed by the computer. Cooling fans – Circulates air in the system unit to keep it cool 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.

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.

Storage – Hard drive, RAM, and secondary storage. 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 MemoryBlue Ray and commercial music CD

ROM RAM

How ROM and RAM work…

CPU

Random Access Memory (RAM)

Random Access Memory (RAM) is a type of memory that stores information temporarily so that it’s available to the CPU.

The more programs open, the slower the computer runs because more RAM is being used and less is available.

RAM is volatile; the memory’s contents are erased when the power is turned off.

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-ROMs 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 diskb. DVD diskc. USB (flash memory) drived. External hard drive

Secondary Storage Devices d. External Hard Drive holds the most

data.

Storage Speed