# 14 Difference Between Digital And Analog Computer

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## What is an Analog Computer?

An analog computer is a type of computer that uses the continuously changeable aspects of physical phenomena such as electrical, mechanical or hydraulic quantities to model the problem being solved. Analog computers store data in continuous form of physical quantities and perform calculations with the help of measures. It is quite different from the digital computer which makes use of symbolic numbers to represent results.

Analog computers are excellent for situations which require data to be measured directly without converting into numerals or codes. Analog computers, although available and used in industrial and scientific applications like control systems and aircraft, have been largely replaced by digital computers due to the wide range of complexities involved.

Analog computers were the earliest computer machines developed and were the among the most complicated machines for analog computation and process control. Analog data is not discrete, but rather is of a continuous nature. Examples of such data are pressure, temperature, voltage, speed and weight. An analog computer makes use of continuous values and not discrete values. Because of this, processes with an analog computer cannot be repeated for exact equivalent results. Unlike digital computers, analog computers are immune to quantization noise. Some of the common computing elements found in analog computers are function generators, integrators, comparators and multipliers. Depending on the application, other specialized components can also be used. Programming on an analog computer involves transformation of the problematic equations into the analog computer circuit.

There are certain advantages associated with analog computers. Real-time operation and simultaneous computation is possible with the help of analog computers. Analog computers can also provide the insight of the problems and errors in case of analog issues for users.

### What You Need To Know About Analog Computer

• Digital computers works with discrete values or these types of systems process discrete data.
• Speed of analog computers is less than the digital computers.
• Analog computer has very low or limited memory and it can store fewer amounts of data.
• These computers use signal generators and network of resistors and capacitors.
• Analog computers produce output as voltage signals and have sets of analog meters and oscilloscopes to display the voltages.
• Analog computers have a limited ability to mimic digital systems.
• Analog computers must deal with a certain minimum level of noise in the circuits and this affects accuracy.
• Assembling of an analog computer entails connection of different sub-systems together electrically with patch cables.
• Examples include: Thermometer, analog clock, older weighing machines, Car speedometer, voice, radio/tv signal etc.
• They have a high power consumption.
• Analog computers are used mainly in engineering and scientific applications.
• Data storage for analog computers is more difficult as they use continuous signals. A circuit that stores an analog signal is prone to drift over time.
• Analog computers are less reliable than digital computers.

## What is a Digital Computer?

A digital computer is any class of devices capable of solving problems by processing information in discrete form. It operates on data, including magnitudes, letters and symbols that are expressed in binary code i.e using only the two digits 0 and 1. By counting, comparing and manipulating these digits or their combinations according to a set of instructions held in its memory, a digital computer can perform such tasks as to control industrial processes and regulate the operations of machines; analyze and organize vast amounts of business data and simulate the behavior of dynamic systems e.g global weather patterns and chemical reactions) in scientific research.

A typical digital computer system has four main functional elements: Input-output equipment, main memory, control unit and arithmetic logic unit. Common input devices include keyboards and optical scanners whereas output devices include printers and monitors. The control unit selects and calls up instructions from the memory in appropriate sequence and relays proper commands to appropriate unit. The ALU on the other hand, performs arithmetic and logic algorithms selected to process the incoming data at extremely high speeds. Examples of digital electronic computers include the IBM PC, the Apple Macintosh as well as modern smartphones.

### What You Need To Know About Digital Computer

• Analog computers works with continuous values or these types of systems process continuous data.
• The analog computers measure the analog quantities like voltage, temperature etc.
• Digital computer has very big memory it can store large amount of data.
• These computers use a variety of on-off switching circuits such as microprocessors, clock pulse generators and logic gates.
• Digital computers produce numbers as output. The computer uses display screens, printers, disc drives and other peripherals to capture this output.
• Digital computers can emulate the behavior of analog computers.
• Digital computers circuits also have electrical noise, though it has little to no effect on accuracy or reliability.
• Assembly of digital computer use carefully written lists of intricate instructions, including comparing two numbers, moving data from one location to another or multiplying two numbers together.
• Examples include: digital watches, digital weighing machines, mini computers, microcomputers, mainframe computers and super computers.
• They have a low power consumption.
• Digital computers can be used in almost all fields of life.
• The numeric and discrete nature of digital computers make data storage simple. A memory circuit copies and retains the discrete states of another circuit.
• Digital computers are more reliable than analog computers.

## Difference Between Digital And Analog Computer In Tabular Form

 BASIS OF COMPARISON ANALOG COMPUTER DIGITAL COMPUTER Description Digital computers works with discrete values or these types of systems process discrete data. Analog computers works with continuous values or these types of systems process continuous data. Working Speed of analog computers is less than the digital computers. The analog computers measure the analog quantities like voltage, temperature etc. Memory Analog computer has very low or limited memory and it can store fewer amounts of data. Digital computer has very big memory it can store large amount of data. Components These computers use signal generators and network of resistors and capacitors. These computers use a variety of on-off switching circuits such as microprocessors, clock pulse generators and logic gates. Output Analog computers produce output as voltage signals and have sets of analog meters and oscilloscopes to display the voltages. Digital computers produce numbers as output. Mimicry Ability Analog computers have a limited ability to mimic digital systems. Digital computers can emulate the behavior of analog computers. Electrical Noise Analog computers must deal with a certain minimum level of noise in the circuits and this affects accuracy. Digital computers circuits also have electrical noise, though it has little to no effect on accuracy or reliability. Assembly Assembling of an analog computer entails connection of different sub-systems together electrically with patch cables. Assembly of digital computer use carefully written lists of intricate instructions, including comparing two numbers, moving data from one location to another or multiplying two numbers together. Power Consumption They have a high power consumption. They have a low power consumption. Usage Analog computers are used mainly in engineering and scientific applications. Digital computers can be used in almost all fields of life. Data Storage Data storage for analog computers is more difficult as they use continuous signals. The numeric and discrete nature of digital computers make data storage simple. Reliability Analog computers are less reliable than digital computers. Digital computers are more reliable than analog computers. Examples Thermometer, analog clock, older weighing machines, Car speedometer, voice, radio/tv signal etc. Digital watches, digital weighing machines, mini computers, microcomputers, mainframe computers and super computers.