Explain about computer with a neat block diagram?

Answer 1

Computers need to receive data and instruction in order to solve any problem. Therefore, we need to input the data and instructions into the computers. The input unit consists of one or more input devices. Keyboard is the one of the most commonly used input device. Other commonly used input devices are the mouse, floppy disk drive, magnetic tape, etc. All the input devices perform the following functions.

1) Accept the data and instructions from the outside world.

2) Convert it to a form that the computer can understand.

3) Supply the converted data to the computer system for further processing.

Storage Unit:

The storage unit of the computer holds data and instructions that are entered through the input unit, before they are processed. It preserves the intermediate and final results before these are sent to the output devices. It also saves the data for the later use.

Types of Storage Devices:

1. Primary Storage:

1. Stores and provides very fast.

2. This memory is generally used to hold the program being currently executed in the computer, the data being received from the input unit, the intermediate and final results of the program.

3. The primary memory is temporary in nature. The data is lost, when the computer is switched off.

4. In order to store the data permanently, the data has to be transferred to the secondary memory. The cost of the primary storage is more compared to the secondary storage.

2. Secondary Storage:

1. It stores several programs, documents, data bases etc.

2. The programs that run on the computer are first transferred to the primary memory before it is actually run.

3. Whenever the results are saved, again they get stored in the secondary memory.

4. The secondary memory is slower and cheaper than the primary memory. Some of the commonly used secondary memory devices are Hard disk, CD, etc.

Memory Size:

All digital computers use the binary system, i.e. 0s and 1s. Each character or a number is represented by an 8 bit code. The set of 8 bits is called a byte. A Character occupies 1 byte space. A numeric occupies 2 byte space. Byte is the space occupied in the memory. The size of the primary storage is specified in KB (Kilobytes) or MB (Megabyte). One KB is equal to 1024 bytes and one MB is equal to 1000KB. The size of the primary storage in a typical PC usually starts at 16MB. PCs having 32 MB, 48MB, 128 MB, 256MB memory are quite common.

Arithmetic Logical Unit:

All calculations are performed in the Arithmetic Logic Unit (ALU) of the computer. It also does comparison and takes decision. The ALU can perform basic operations such as addition, subtraction, multiplication, division, etc and does logic operations viz >, <, = etc.

Whenever calculations are required, the control unit transfers the data from storage unit to ALU once the computations are done, the results are transferred to the storage unit by the control unit and then it is send to the output unit for displaying results.

Output Unit:

The output unit of a computer provides the information and results of a computation to outside world. Printers, Visual Display Unit (VDU) are the commonly used output devices. Other commonly used output devices are floppy disk drive, hard disk drive, and magnetic tape drive.

Control Unit:

It controls all other units in the computer. The control unit instructs the input unit, where to store the data after receiving it from the user. It controls the flow of data and instructions from the storage unit to ALU. It also controls the flow of results from the ALU to the storage unit. The control unit is generally referred as the central nervous system of the computer that control and synchronizes its working.

Central Processing Unit:

The control unit and ALU of the computer are together known as the Central Processing Unit (CPU). The CPU is like brain performs the following functions:

1) It performs all calculations.

2) It takes all decisions.

3) It controls all units of the computer.

A PC may have CPU-IC such as Intel 8088, 80286, 80386, 80486, Celeron, Pentium, Pentium Pro, Pentium II, Pentium III, Pentium IV, Dual Core, and AMD etc.

Answer 2

The main "blocks" of a digital computer system are:

• ALU (arithmetic logic unit)
• Central RAM (random access memory)
• CU (control unit)
• I/O (input/output interface units)
• Storage devices
• Communications devices

More details

Input units

Digital computers need to receive data and instruction in order to solve any problem so they need to input data and instructions. Input can be entered from a keyboard, a mouse pointing device, a USB stick and the various types of photo storage cards used by digital cameras. Input can also be downloaded from the internet via a communications device.

Older personal computers used floppy disks and magnetic tape devices. Even older designes of mini-computers and main-frame computers took their input from punched cards, paper tape, etc. as well as communications devices.

All input peripheral devices perform the following functions:

• Accept the data and instructions from the outside world.
• Convert it to a form that the computer can understand.
• Supply that converted data to the computer system for further processing.

Storage Units

The storage units of a digital computer hold data and instructions that have been entered through the input unist before and whilst they are being processed. They preserve the intermediate and final results before they are sent to the output devices. They also save the data for the later use. The various storage devices of a computer system are divided into two categories:

1. Primary Storage: Random Access Memory. (RAM)

This stores and delivers data very fast.

RAM is generally used to hold the program being currently executed in the computer, the data being received from the input unit and the intermediate and final results of the program. RAM memory is temporary in nature: the data is lost when the computer is switched off.

In order to store the data permanently, the data has to be transferred to the secondary memory.

Primary storage costs more per megabyte compared to secondary storage. Therefore most computers have limited primary storage capacity.

2. Secondary Storage.

Secondary storage is used like an archive. It stores several programs, documents, data bases etc. The programs that you run on the computer are first transferred to the primary memory before it is actually run. Whenever the results are saved, again they get stored in the secondary memory. The secondary memory is slower and cheaper than the primary memory. Some of the commonly used secondary memory devices are Hard disk, USBStick, CD, DVD, etc.

Memory Size

All digital computers use the binary system, i.e. 0's and 1's. Each character or a number is represented by an 8 bit code. A set of 8 bits is called a byte. Depending on the method of encoding used, a plain character can occupy one or two bytes of space.

The size of the primary storage is specified in KB (kilobytes), MB (megabytes) and GB (Gigabytes). One KB is equal to 1024 bytes, one MB is equal to 1000 KB and one GB is equal to 1000 MB. Nowadays the size of the primary storage in a typical PC usually starts at around 1/2 GB. PCs having 1GB, 2GB or 4GB of RAM memory are now quite common.

Output Units

The output units of a computer provide the information and results of an arithmetical computation - or some other kind of data processing, such as a search - to the outside world. Commonly used output units are printers and visual display units (VDUs), also known simply as "screens". Output data can also be sent to USB sticks and other types of data storage cards, such as those used by digital cameras. Output can also be uploaded to the Internet via a communications device.

Older personal computers used floppy disks and magnetic tape devices. Even older designes of mini-computers and main-frame computers sent their output to punched cards, paper tape, etc.as well as communications devices.

All output peripheral devices perform the following functions:

• Accept output data and instructions from the computer.
• Convert it to a form that the outside world can understand.
• Supply that converted data to the outside world.

Arithmetic Logical Unit (ALU)

All calculations are performed in the Arithmetic Logic Unit (ALU) of the computer.

It also does comparisons and takes decisions.

The ALU can perform basic operations such as addition, subtraction, multiplication, division, etc and does logic operations viz, >, <, =, 'etc. Whenever calculations are required, the control unit transfers the data from storage unit to ALU once the computations are done, the results are transferred to the storage unit by the control unit and then it is send to the output unit for displaying results.

Control Unit

This controls all the other units in the computer. The control unit instructs the input units where to store the data after receiving it from the user/ the outside world. It controls the flow of data and instructions from the storage units to ALU. It also controls the flow of results from the ALU to the storage units and to the output units which send it to the user/the outside world. The control unit is generally referred as the "central nervous system" of the computer that controls and synchronizes its overall working.

Central Processing Unit

The control unit and ALU of the computer are together known as the Central Processing Unit (CPU). The CPU is like brain performs the following functions:

• It performs all calculations.

• It takes all decisions.

• It controls all units of the computer.

Nowadays a personal computer has its CPU on an integrated circuit device manufactured by firms such as Intel, AMD, etc.

Answer 3

basic building block of a digital computer and it's working of each blocks

Answer 4

You can find pictures of how to do this online. You can use this as a guide and then write out the explanation to use for your project.

Answer 5

vipin somra