Computer System ( Memory).......:)

Memory
•Memory consists of electronic components that store instructions waiting to be executed by the processor, data needed by those instructions, and the results of processing the data.

•Each location in memory has an address
•Memory size is measured in kilobytes(KB or K), megabytes(MB), gigabytes(GB), orterabytes(TB).

Type of memory

• volatile
• non volatile

 Volatile memory
•When the computer’s power is turned off, volatile memory loses its contents.
•Volatile memory is temporary.
•RAM is the most common type of volatile memory
Discovering

Nonvolatile memory

•Nonvolatile memory does not lose its contents when power is removed from the computer.
•Nonvolatile memory is permanent.
•Examples of nonvolatile memory include ROM.

Differences between volatile and non-volatile

volatile (ROM)

• Loses its contents when power is turned off
• (store data for temporary time only)
• Can be read from and written to by the processor and other devices.
  Hold data or programs that are currently being used by the processor.
• RAM chip are assembled on a small circuit board called memory module which is plugged onto the memory slots.

non volatile

• Does not lose contents when power is removed (store data permanently).
• Data is prerecorded for read only and cannot be modified or removed.
• Contain a small startup program (BIOS) which is used to boot the computer.
• Exists as a chip on the motherboard.

explanation and example of RAM

•RAM chips usually reside on a memory moduleand are inserted into memory slot
•The amount of RAM necessary in a computer often depends on the types of software you plan to use.

example of RAM

• DRAM(Dynamic RAM )
• SRAM(Static RAM )
• MRAM(Magnetoresistive RAM)

 explanation and example of ROM

•Read-only memory (ROM) refers to memory chips storing permanent data and instructions.
•The data on most ROM chips cannot be modified.

example of ROM

• PROM(Programmable Read-Only Memory)
• EPROM(Erasable Read-Only Memory)
• EEPROM(Electrically Erasable Programmable Read-Only Memory)

Pagar Logik???? a.k.a Logic+Gates

Computer System:Boolean Expression

Logical Operators

• AND (.)

• OR (+)

• NOT (~, !, ¯ )

                                               

Example of Boolean Expression

1.A AND B OR C

A.B+C

2.A AND B NOT C

(A.B)~C

3.NOT ((A AND B) OR C)

~[(A.B)+C]

Logical Operator : AND (.)

Example :

Given A=1, B=1, C=0

Write a value for the expression.

                                                        

                                                         TRUTH TABLE (A.B)

a)A.B

= 1.1

= 1

Hence, A.B = 1

b) A.C                               TRUTH TABLE (A.C)

 = 1.0                              

 = 0

 Hence, A.C = 0

Logical Operator : OR (+)

Example :
Given A=1, B=1, C=0
Write a value for expression

a) A + B    TRUTH TABLE  (A + B)

 = 1 + 1     
 = 1      
Hence, A + B = 1

b) A  + C                                                                   TRUTH TABLE  (A + C )

= 1 + 0                            

= 1  

Hence, A + C = 1

Logical Operator : NOT(~, !, ¯ )

Example :

Given A=1, B=1

Write a value for the expression.

a) !A                               TRUTH TABLE (!A)

= !(1)     

 = 0    

Hence, !A = 0

b) !(A + B)                        TRUTH TABLE !(A + B)  

= ! (1 + 1)                        = ! (1)  

= 0  

Hence, !(A+B) = 0 

WHAT IS NETWORK ? 0_O

 NETWORK IS . . .

 * A network is a collection of computers and devices  connected together via communications devices and    transmission media

( Examples of network ................)

      Advantages of Using a Network?

Sharing hardware

Sharing software

Sharing data and information

Facilitating communications

Transferring funds

Network Architecture

   •The design of computers, devices, and media on a network is sometimes called the network architecture.

What Is a Topology?

A network topology refers to the layout of

the computers and devices in a

communications network.

It refers to both the physical and logical

layout of a network.

Layout of Network

Physical Topology

 The arrangement of a cabling is the physical

    topology.

Logical Topology

 The path that data travels between computers

    on a network is the logical topology.

Types of

 network topology :

*BUS NETWORK

*STAR NETWORK

*RING NETWORK

to be continued ..............

What Is SYSTEM UNIT???? Zassssssssssss......

•       The system unit is a case that contains electronic  components of the computer used to process data.
• 
  
•         The case of the system unit, sometimes called the chassis is made of metal or plastic and protects the internal electronic components from damage.
• 
  
•         All computers and mobile devices have a system unit. 

System unit also known as :

• "computer chassis",
• "tower", 
• "base unit" or simply "case".
• "system unit", 

Also sometimes incorrectly referred to as the "CPU"

• Main components inside the computer:

1) Motherboard
2) Adapter cards
3) Processor 
4) Memory

MOTHERBOARD

•The motherboard is the main circuit board of the system unit

- A computer chip contains integrated circuits.

The functions of the motherboard are:

lHolds many components of the system.

lProvides connectors for other peripherals.

Basic Component of motherboard :

lProcessor Slot

lMemory Slots

lAdapter Card Slots

PROCESSOR SLOT

- Slot on the motherboard that houses a CPU and forms the

electrical interface with the CPU.

MEMORY SLOT

lSlots on the motherboard that hold memory modules.

lTo connect RAM and get faster of the performance of computer.

ADAPTER CARD SLOTS

lSlots on the motherboard that can hold adapter cards.

lFor adding more memory, graphics capabilities and support for

special devices.

CPU ( Central Processing Unit )

•The processor, also called the central processing unit (CPU),

interprets and carries out the basic instructions that operate a

computer.

•CPU speeds is measured in gigahertz (GHz). 

•CPU Components :

–Control unit 

–Arithmetic logic unit (ALU)

 CONTROL UNIT

lIs the component of the processor that directs and coordinates most of the operations in the computer.

lThe control unit has a role much like a traffic cop; it interprets each instruction issued by a program and then initiates the appropriate action to carry out the instruction.

ARITHMETIC LOGIC UNIT

lPerforms arithmetic, comparison and other operations.

lArithmetic operations include basic calculations such as addition, subtraction, multiplication and division.

lComparison (logical) operations involve comparing one data item with another to determine whether the first item is greater than, equal to or less than the other item.

MACHINE CYCLE

lThe operations performed by the CPU to execute any instruction.

lFor each instruction, a processor repeats a set of 4 basic operations, which compromise a machine cycle.

ADAPTER CARD

• An expansion slot is a socket on the motherboard that can hold

an adapter card

• An adapter card enhances functions of a component of the

system unit and/or provides connections to peripherals

• A peripheral is a device that connects to the system unit and is

controlled by the processor in the computer. Examples: modems,

printers, scanners, keyboards, sound card and video card

Data Representation ..(Y)

Let's know about : ~~

How does a computer represent data?

 *By using two unique binary digits 1 and 0 to  represent    the two states on and off.

     *A computer circuit represents the 0 or the 1      electronically by the presence or absence of an  electrical charge.

BIT

* Is the smallest unit of data the computer can  process.

* (Short for binary digit )

* The number system has two unique digits, 1 (on)  or 0 (Off)

* Represents an electrical state (on or off)

BYTE

* A group of 8 bits (ex:11110000)

* Represents a single character such as a digit, a  letter, a punctuation mark or any symbol in  computer

     

Thank you ! :D

Application Software ..

Application Software

•To make business activities more efficient
•To assist with graphics and multimedia projects
•To support home, personal, and educational tasks
•To facilitate communications

Type of software

o  Open source software

   -created by unpaid volunteers, begin to gain wide acceptance among computer users.

    -Freely

o  Proprietary software

   -privately owned and limited to a specific vendor or computer model.

    -license / paid

WEB BROWSER

   *allows users to access and interact with software from     any computer or device that is connected to the Internet

*View Web pages or access programs  example:

§  Google chrome

§  Firefox opera

  WORD PROCESSING

    *allows users to create and      manipulate documents example:

               § Microsoft Office Word  

               § OpenOffice.org Writer

SPREADSHEET

  *allows users to organize data in rows and columns and perform calculations

   *Usage to create personal profiles, budget summaries, income statements or calculate students marks.Examples :-

§ Microsoft Office Excel

              § OpenOffice.org Calc

         PRESENTATION

  *allows users to create visual aids for presentations to communicate ideas, messages, and other information to a group  

   *Usage to create a presentation for teaching, marketing   or tourist information. Examples :-

§ Microsoft  Office PowerPoint

§ OpenOffice.org Impress 

DATABASE

 *is a collection of data organized in a manner that allows access, retrieval, and use of that data

   –Database software allows users to create,     access, and manage a database

   –Usage to create student database, employees database or book database. Examples :

§ Microsoft Office Access

                          § OpenOffice.org Base

That's all :)