Information TechnologyInformation TechnologyBasic Computer ArchitectureBasic Computer Architecture

Adnan KhalidAdnan Khalid

Basic Computer ArchitectureBasic Computer Architecture

Output Output DeviceDeviceInput Input

DeviceDevice

Memory UnitMemory Unit

AuxiliaryAuxiliaryStorage Storage DeviceDevice

Central Processing Central Processing UnitUnit

Arithmetic Logic Arithmetic Logic UnitUnit

Control UnitControl UnitRAMRAM

Components of ComputersComponents of Computers

Central Processing UnitCentral Processing Unit Arithmetic and Logic UnitArithmetic and Logic Unit Control UnitControl Unit Memory Unit Memory Unit

MemoryMemory Random Access Memory (RAM)Random Access Memory (RAM) Read Only Memory (ROM)Read Only Memory (ROM)

Input and Output DevicesInput and Output Devices Storage DevicesStorage Devices

The Central Processing UnitThe Central Processing Unit

The CPU is like the brain of the The CPU is like the brain of the computer.computer.

It organizes the instructions It organizes the instructions provided by the user or the provided by the user or the software.software.

The CPU consists of three parts The CPU consists of three parts namely, Arithmetic and logic namely, Arithmetic and logic unit, Control Unit and Memory unit, Control Unit and Memory Unit.Unit.

Arithmetic and Logic UnitArithmetic and Logic Unit

All operations in a computer are All operations in a computer are performed by the arithmetic and logic performed by the arithmetic and logic unit.unit.

It performs two types of operations, It performs two types of operations, Arithmetic and Logical.Arithmetic and Logical.

Arithmetic operations are addition, Arithmetic operations are addition, subtraction, multiplication and subtraction, multiplication and division.division.

Logical operations are < > and =.Logical operations are < > and =.

Control UnitControl Unit

The control unit (CU) controls The control unit (CU) controls the flow of data from the main the flow of data from the main memory to the ALU and from memory to the ALU and from the ALU to the main memory.the ALU to the main memory.

It is the stage manager of the It is the stage manager of the whole concert.whole concert.

Memory or Primary StorageMemory or Primary Storage

There are two types of primary There are two types of primary storage namely,storage namely, Random Access Memory (RAM) Random Access Memory (RAM)

and,and, Read Only Memory (ROM)Read Only Memory (ROM)

Memory or Primary StorageMemory or Primary Storage

Random Access MemoryRandom Access Memory

RAMRAM is an acronym for is an acronym for RRandom andom AAccess ccess MMemory that is also known as volatile emory that is also known as volatile memory, because the data it holds is lost memory, because the data it holds is lost when the when the desktop PC or or laptop/notebook computer using it is switched using it is switched off. Briefly, RAM memory is used by the off. Briefly, RAM memory is used by the system to store data in the form of files for system to store data in the form of files for processing by a computer's central processing processing by a computer's central processing unit (CPU), also known as the unit (CPU), also known as the processor. .

Types of RAMTypes of RAM

SRAMSRAM Short for static random Short for static random access memory, and pronounced access memory, and pronounced ess-ram. SRAM is a type of memory ess-ram. SRAM is a type of memory that is faster and more reliable than that is faster and more reliable than the more common DRAM (dynamic the more common DRAM (dynamic RAM). The term static is derived RAM). The term static is derived from the fact that it doesn't need to from the fact that it doesn't need to be refreshed like dynamic RAM.be refreshed like dynamic RAM.

DRAM DRAM stands for dynamic random stands for dynamic random access memory, a type of memory access memory, a type of memory used in most personal computers. used in most personal computers.

Read Only MemoryRead Only Memory

Read Only Memory (ROM) is Read Only Memory (ROM) is that memory which contains a that memory which contains a set of start-up instructions called set of start-up instructions called the Basic Input Output System the Basic Input Output System (BIOS) for the computer.(BIOS) for the computer.

It is non-volatile i.e. it holds data It is non-volatile i.e. it holds data when the computer is turned off.when the computer is turned off.

Types of ROM Types of ROM PROM PROM short for programmable read-only memory A PROM short for programmable read-only memory A PROM

is a memory chip on which data can be written only once. is a memory chip on which data can be written only once. Once a program has been written onto a PROM, it remains Once a program has been written onto a PROM, it remains there forever. Unlike RAM, PROM's retain their contents there forever. Unlike RAM, PROM's retain their contents when the computer is turned off. The difference between a when the computer is turned off. The difference between a PROM and a ROM (read-only memory) is that a PROM is PROM and a ROM (read-only memory) is that a PROM is manufactured as blank memory, whereas a ROM is manufactured as blank memory, whereas a ROM is programmed during the manufacturing process. To write programmed during the manufacturing process. To write data onto a PROM chip, you need a special device called a data onto a PROM chip, you need a special device called a PROM programmer or PROM burner. The process of PROM programmer or PROM burner. The process of programming a PROM is sometimes called burning the programming a PROM is sometimes called burning the PROM.PROM.

EPROMEPROM (erasable programmable read-only memory) is a (erasable programmable read-only memory) is a special type of PROM that can be erased by exposing it to special type of PROM that can be erased by exposing it to ultraviolet light. Once it is erased, it can be reprogrammed. ultraviolet light. Once it is erased, it can be reprogrammed. An EEPROM is similar to a PROM, but requires only An EEPROM is similar to a PROM, but requires only electricity to be erased.electricity to be erased.

EEPROMEEPROM- Acronym for electrically erasable programmable - Acronym for electrically erasable programmable read-only memory. Pronounced double-ee-prom or e-e-read-only memory. Pronounced double-ee-prom or e-e-prom, an EEPROM is a special type of PROM that can be prom, an EEPROM is a special type of PROM that can be erased by exposing it to an electrical charge. Like other erased by exposing it to an electrical charge. Like other types of PROM, EEPROM retains its contents even when types of PROM, EEPROM retains its contents even when the power is turned off. the power is turned off.

Input and Output DevicesInput and Output Devices

The Devices used to enter The Devices used to enter data into a computer are data into a computer are called called Input DevicesInput Devices, while , while those used to retrieve data those used to retrieve data from the computer are called from the computer are called Output DevicesOutput Devices..

Input DevicesInput Devices

KeyboardKeyboard MouseMouse JoystickJoystick ScannerScanner Digital CameraDigital Camera MicrophoneMicrophone Touch ScreenTouch Screen Bar Code ReaderBar Code Reader

KeyboardKeyboard

The keyboard is a way to input letters or numbers into different applications or programs.  A keyboard also has special keys that help operate the computer.

MouseMouse

The mouse is used to open and The mouse is used to open and close files, navigate web sites, and close files, navigate web sites, and click on a lot of commands (to tell click on a lot of commands (to tell the computer what to do) when the computer what to do) when using different applications. using different applications.

JoystickJoystick

A joystick is used to move the cursor A joystick is used to move the cursor from place to place, and to click on from place to place, and to click on various items in programs.  A various items in programs.  A joystick is used mostly for computer joystick is used mostly for computer games. games.

ScannerScanner

A scanner is used to copy pictures or A scanner is used to copy pictures or other things and save them as files other things and save them as files on the computer.  on the computer. 

Digital CameraDigital Camera

A digital camera can be used to take A digital camera can be used to take pictures.  It can be hooked up to a pictures.  It can be hooked up to a computer to transfer the pictures from the computer to transfer the pictures from the camera to the computer.  Some digital camera to the computer.  Some digital cameras hold a floppy disk, and the cameras hold a floppy disk, and the floppy disk can be taken out of the floppy disk can be taken out of the camera and put directly into the camera and put directly into the computer. computer.

MicrophoneMicrophone

A microphone is used to record A microphone is used to record sound.  The sound is then saved as sound.  The sound is then saved as a sound file on the computer. a sound file on the computer.

Touch ScreenTouch Screen

A touch screen is a computer screen or A touch screen is a computer screen or other screen that you can touch with your other screen that you can touch with your finger to enter information.  Examples of finger to enter information.  Examples of touch screens include a smart board, a touch screens include a smart board, a microwave, a dishwasher, or an ATM at a microwave, a dishwasher, or an ATM at a bank. bank.

Barcode ReaderBarcode Reader

A bar code scanner scans a little A bar code scanner scans a little label that has a bar code on it. The label that has a bar code on it. The information is then saved on the information is then saved on the computer. Bar code scanners are computer. Bar code scanners are used in libraries a lot. used in libraries a lot.