Classification of Computer (Analog, Digital, Hybrid) | Computer Architecture and Organisation

What is a Digital Computer?

Digital Computer is a machine or a device that helps to process any kind of information.

These are the devices through which we provide some input and get the output within a fraction of seconds.

The operations that are conducted internally in the device happens using the binary number system since the computer understands only digits ie 0’s and 1’s.

All the content that is written in English will be converted to binary language and thus computers and humans communicate with each other.

Some of the basic examples of digital devices are Personal computers, Desktops, Laptops, Smartphones, and Mobiles.

There are mainly three parts in a digital computer and it consists of –

· Input: User normally provides the data to the device that is known as input.

· Processing: The input that is provided by the user is processed internally using some defined sequence.

· Output: Once the processing is completed, based on the input, the output is displayed         to the user.

Different types of Digital Computer

Digital computers are a device that needs to be programmed in order to receive the desired output.

It uses electronic technology to generate, store and process different types of data.

Based on the size and type of the device, these digital computers are classified into four categories.

· Microcomputer

· Minicomputer

· Mainframe computer

· Supercomputer

Microcomputer

A Microcomputer is not really expensive and it comes with a microprocessor as its Central Processing Unit and input/output devices.

These computers are generally called personal computers and few of the examples are IBM pc, Apple, Dell.

Minicomputers

Minicomputers are known as mid-range computers that contain one or more processors.

They support multiprocessing which means these multiple processors share the same computer memory and other required peripheral devices to perform the given task.

Minicomputers are generally used for processing transactions, file handling, managing database.

Mainframe computers

Mainframe computers are generally large size computers mainly used for storing large amounts of data and processing. It is known for a high level of reliability.

These machines are used by an organization which requires crucial application such as census, customer statistics for large calculation which requires a high volume of data processing.

 

Super Computers

Supercomputers are very expensive and the world’s fastest computers available.

These computers have thousands of processors that perform trillions of calculations per second and hence the fastest known ever.

Supercomputers are used extensively in enterprises and organizations that require massive calculations.

 

Classification of computers

Computers can be categorized into Analog, Digital and Hybrid Computers. Each category is used for its own purpose and has its own significance.

Analog Computers

Analog computers are mainly based on voltages and current with continuous electrical signals and display the output continuously.

These computers store the data and perform calculations quite differently than digital computers which make use of symbolic representation.

These are generally slower in speed compared to digital computers. Some of the examples are thermometer.

Digital Computers

Digital computers are computers that process the data in binary form ie.0’s and 1’s.

The main benefit of digital computers is that they are quick and re-programmable.

Some of the examples are laptops, smartphones, and calculators.

Hybrid Computers

Hybrid computers are a special purpose computer that has a combination of both Analog and digital computers.

They are digital computer which accepts Analog signals and converts them to digital form.

These are generally used for scientific applications, airplanes, and hospitals.

Some of the examples include electrocardiogram machine, ultrasound machine, monitoring machine.

Advantages and disadvantages of 

Digital/Analog computer

The main advantage of Digital computers is that they can store loads of data and it is very accurate.

Analog computer is quick and hence fastest. Digital computers are comparatively slower than Analog and this is the main disadvantage.

Analog computers stores fewer data and hence digital computers are great of memory is considered

 Features of Digital computer

· Good Memory – Digital computers can store a large number of data and can retrieve data in a fraction of second. The data can be stored for any duration and retrieved anytime.

· Very Flexible – These computers can perform multi-tasking without any human interference and hence they are very flexible and versatile.

· Automatic – These devices once started are automatic. They do not need any intervention until required by the task specifically.

· Good Speed – Digital computers are high in speed and carry out all the operations with very fast speed.

· Accurate – These devices help in storing all the information which helps in retrieving accurate data at any point in a given time.

RISC and CISC | Computer Architecture and Organization

Exam Notes For COA

What is RISC and CISC  With Characteristic (Important)

                                   OR

Instruction set based Classification of  Processor

Anwser.  The important Aspect of the computer Architecture is the design of Instruction Set  for the Processor.

 Instruction set of processor includes the two types i.e

(a) RISC  ( Reduced Instruction Set of Computer)

(b) CISC (Complex Instruction  set of Computer)

What is RISC?

A reduced instruction set computer is a computer that only uses simple commands that can be divided into several instructions that achieve low-level operation within a single CLK cycle, as its name proposes “Reduced Instruction Set”.

RISC Architecture

The term RISC stands for ‘’Reduced Instruction Set Computer’’. It is a CPU design plan based on simple orders and acts fast.

RISC Architecture

This is a small or reduced set of instructions. Here, every instruction is expected to attain very small jobs. In this machine, the instruction sets are modest and simple, which help in comprising more complex commands. Each instruction is of a similar length; these are wound together to get compound tasks done in a single operation. Most commands are completed in one machine cycle. This pipelining is a crucial technique used to speed up RISC machines.

Characteristic of RISC –

1. Simpler instruction, hence simple instruction decoding.
2. Instruction come under size of one word.
3. Instruction take single clock cycle to get executed.
4. More number of general purpose register.
5. Simple Addressing Modes.
6. Less Data types.
7. Pipeling can be achieved.

What is CISC?

A complex instruction set computer is a computer where single instructions can perform numerous low-level operations like a load from memory, an arithmetic operation, and a memory store or are accomplished by multi-step processes or addressing modes in single instructions, as its name proposes “Complex Instruction Set ”.

CISC Architecture

The term CISC stands for ‘’Complex Instruction Set Computer’’. It is a CPU design plan based on single commands, which are skilled in executing multi-step operations.

CISC Architecture

CISC computers have small programs. It has a huge number of compound instructions, which takes a long time to perform. Here, a single set of instructions is protected in several steps; each instruction set has additional than 300 separate instructions. Maximum instructions are finished in two to ten machine cycles. In CISC, instruction pipelining is not easily implemented.

Characteristic of CISC –

1. Complex instruction, hence complex instruction decoding.
2. Instruction are larger than one word size.
3. Instruction may take more than single clock cycle to get executed.
4. Less number of general purpose register as operation get performed in memory itself.
5. Complex Addressing Modes.
6. More Data types.

Difference between RISC and CISC Architecture

Difference between RISC and CISC

 RISC                                                          CISC

Focus on software	Focus on hardware
Uses only Hardwired control unit	Uses both hardwired and micro programmed control unit
Transistors are used for more registers	Transistors are used for storing complex Instructions
Fixed sized instructions	Variable sized instructions
Can perform only Register to Register Arthmetic operations	Can perform REG to REG or REG to MEM or MEM to MEM
Requires more number of registers	Requires less number of registers
Code size is large	Code size is small
A instruction execute in single clock cycle	Instruction take more than one clock cycle
A instruction fit in one word	Instruction are larger than size of one word