20 Examples of Analog Computers

Published: 9 Jul 2025

Is a wall clock a computer? That sounds strange, right? But wait, if it gives us time using moving hands and gears, isn’t that computing something? Let’s clear the confusion and look at 20 examples of analog computers that might surprise you.

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What is Analog Computer?

An analog computer is a type of computer that solves problems using real-world concepts, such as speed, heat, or time. It does not use numbers like digital computers. Instead, it displays results using moving parts, such as needles or dials. For example, a car’s speedometer is an analog computer. It indicates the car’s speed by moving a needle. Analog computers are simple and help us understand changes in the real world.

20 Examples of Analog Computers

Analog computers are devices that process information using physical quantities such as speed, temperature, and pressure, rather than digital numbers. Below are 20 examples of analog computers that were used across various fields to perform important calculations and tasks.

Slide Rule
Pedometer
Planimeter
Nomogram
Antikythera Mechanism
Differential Analyzer
Water Integrator
Reeves Electronic Analog Computer (REAC)
AKAT-1
The Analog Thing (THAT)
Astrolabe
Torquetum
Kerrison Predictor
Norden Bombsight
Castle Clock
Tide Predicting Machine
Mechanical Calculator
Analog Oscilloscope
Analog Sound Processor
Librascope

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Slide Rule

A slide rule is a wise ruler that people used before calculators were invented. It helped students, engineers, and scientists solve math problems like multiplication, division, square roots, and more. You move the sliding parts to find answers. Even though it does not use electricity, it was fast and helpful for many years.

Advantages and Disadvantages of Slide Rule:

Like every tool, the slide rule has both its advantages and disadvantages. It helped many people do math before calculators were standard. But it also has some limits. Let’s look at the main benefits and problems of using a slide rule in real life.

Advantages of Slide Rule
No need for electricity or batteries Quick for basic math (like multiplication/division) Small and easy to carry Helpful for science and engineering work Builds number sense and estimation skills

Disadvantages of Slide Rule
Not 100% accurate Takes time to learn Can not do all math types No memory or step tracking Feels outdated today

Pedometer

A pedometer is a small device that counts the number of steps you take. People wear it on their waist, wrist, or keep it in their pocket. It helps you know how much you walk in a day. It’s beneficial for staying active and maintaining good health.

Advantages and Disadvantages of Pedometer:-

A pedometer is a helpful tool, but like all tools, it has both its strengths and weaknesses. It can make walking fun and easy to track, but it also has a few limits. Let’s see the pros and cons of pedometer.

Advantages of Pedometer
Count your steps easily Helps you stay fit and active Small and easy to carry Suitable for daily exercise goals Simple to use for all ages

Disadvantages of Pedometer
May not always count steps correctly Does not track all kinds of movements Some need batteries to work Can break if not handled carefully Limited features compared to fitness watches

Planimeter

A planimeter is a specialized tool used to measure the area of shapes, such as those found on maps or drawings. You move it around the edges of a shape, and it tells you how big the shape is. People like engineers and architects use it to get accurate area measurements without hard math.

Advantages and Disadvantages of Planimeter:-

A planimeter is very helpful when measuring areas, but it’s not perfect. It has many good points, but also a few things that are not so great. Let’s quickly look at both sides to understand how useful it really is.

Advantages of Planimeter
Measures area without hard math Easy to use with practice Suitable for maps and drawings Saves time on big shapes Does not need electricity

Disadvantages of Planimeter
It can be tricky for beginners Needs a steady hand for accuracy Not ideal for tiny shapes Only works on flat surfaces It can be expensive for some users

Nomogram

A nomogram is a special chart that helps solve math problems by using lines and scales. You do not need a calculator to use it. By drawing a straight line across the chart, you can find the answer quickly. It was used a lot before computers became common.

Advantages and Disadvantages of Nomogram:-

Like other old tools, the nomogram has some strong points and some weak spots. It was quick and straightforward for many tasks, but not perfect for everything. Let’s take a look at what it does well and where it falls short.

Advantages of Nomogram
No electricity or batteries needed Fast and easy for specific calculations Can be used anywhere Good for quick estimates Simple tool for trained users

Disadvantages of Nomogram
Not suitable for very complex problems Needs practice to use correctly It can be hard to read for some people Not useful without printed charts Less accurate than modern tools

Antikythera Mechanism

The Antikythera Mechanism is an ancient Greek machine made over 2,000 years ago. It was used to study stars, the moon, and the sun. People say it’s the world’s first analog computer. It had small gears and wheels that helped show the position of planets and important dates. It’s a smart tool built long before modern technology.

Advantages and Disadvantages of Antikythera Mechanism:-

Every tool has its advantages and disadvantages. The Antikythera Mechanism was remarkable for its time, but it also had its limitations. Let’s see what made it special and what things it could not do.

Advantages of Antikythera Mechanism
Showed positions of the sun, moon, and planets Helped predict eclipses and calendars Very advanced for its time Worked without electricity Inspired modern gear-based machines

Disadvantages of Antikythera Mechanism
Very complex and challenging to build Only one was found, no backups Could break easily Hard to understand without training Could not be used for all types of problems

Differential Analyzer

The Differential Analyzer is a large machine used to solve mathematical problems, especially those involving changing numbers. It was made in the early 1900s to help engineers and scientists. This machine used wheels, gears, and motors to display answers without relying on digital components. It helped solve complex problems before the invention of digital computers.

Advantages and Disadvantages of Differential Analyzer:-

Like every machine, the Differential Analyzer had both its advantages and disadvantages. It made math easier, but it was also big and not easy to carry or use. Let’s take a quick look at its strong and weak points.

Advantages of Differential Analyzer
Solves complex math quickly No need for electricity in early models Helped in science and war projects Used genuine physical parts for answers Worked before digital computers existed

Disadvantages of Differential Analyzer
Huge and heavy machine Hard to move or fix Needs training to use Not as accurate as digital computers Could not do many different tasks at once

Water Integrator

The Water Integrator was a computer that used water to solve math problems. It worked by letting water flow through pipes and measuring the results. This helped people solve complicated equations in science and engineering. It was one of the first analog computers used in the 1930s.

Advantages and Disadvantages of Water Integrator:-

Like other old machines, the Water Integrator had some notable uses but also had its share of problems. It helped with big math tasks, but it was not easy to build or carry around. Here are its good and bad points:

Advantages of Water Integrator
Solved challenging math problems using water Did not need electricity Suitable for physics and engineering work Helped show how fluids can do math Inspired future analog machines

Disadvantages of Water Integrator
Big and heavy machine Needed clean water and setup Hard to use and understand Could not do fast changes or updates Not valid for all math types

Reeves Electronic Analog Computer

The Reeves Electronic Analog Computer, or REAC, was one of the first big electronic analog computers. It was developed in the 1940s to assist with challenging math problems, such as those encountered in science and engineering. REAC used electric signals to solve problems fast. It was beneficial before digital computers became common.

Advantages and Disadvantages of Reeves Electronic Analog Computer:-

REAC was a powerful machine for its time. It helped solve tricky problems quickly. However, like all tools, it had both its advantages and disadvantages. Let’s look at both sides.

Advantages of Reeves Electronic Analog Computer
Solved big math problems quickly Used in science, space, and defense work Very fast for the 1940s Could handle real-world data like speed or pressure Helped design early airplanes and rockets

Disadvantages of Reeves Electronic Analog Computer
Very large and heavy Needed expert operators Hard to repair or upgrade Not as accurate as later digital computers Used a lot of power and space

AKAT-1

AKAT-1 was the first transistor-based analog computer made in Poland in the 1950s. It was created to help with solving control system problems and engineering tasks. Unlike older machines, it used small parts called transistors instead of big vacuum tubes. This made it smaller and better for specific jobs.

Advantages and Disadvantages of AKAT-1:-

AKAT-1 was a smart step forward in analog computers. It had many helpful features, but it also had a few limits. Let’s quickly see the good and bad sides of this unique machine.

Advantages of AKAT-1
First to use transistors, not vacuum tubes Smaller and more reliable Suitable for solving control system problems Used in engineering and science work Made computers faster and more modern

Disadvantages of AKAT-1
Still large by today’s standards Needed expert people to use it Could only solve specific types of problems Hard to maintain Limited to analog tasks only

The Analog Thing

THE ANALOG THING, also known as THAT, is a modern analog computer made for students and hobbyists. It is a small and portable device that helps people learn how analog computers work by solving real-life problems using electrical signals. Even today, it is used in schools, universities, and science experiments for hands-on learning.

Advantages and Disadvantages of THE ANALOG THING:-

Like every tool, THE ANALOG THING has both strengths and limitations. It is helpful in many ways, especially for learning, but it also has a few downsides. Here’s a quick look at both the advantages and disadvantages.

Advantages of THE ANALOG THING
Easy to use for learning and teaching Small and lightweight Great for understanding analog computing Does not require any coding or software Affordable and reusable

Disadvantages of THE ANALOG THING
Can only solve simple problems Not suitable for large scientific projects Requires basic knowledge of electronics No option to save or print results Slower than modern digital tools

Astrolabe

The astrolabe is an old tool used by sailors and scientists to study the stars and the sky. It was created many years ago to help people find time, direction, and location by observing the sun and stars. People used it for travel, prayer times, and learning about space. It is one of the oldest analog computers ever made.

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Advantages and Disadvantages of Astrolabe:-

The astrolabe was a helpful tool in the past. It provided people with numerous benefits, but it also had its limitations. Let’s take a quick look at what made it worthwhile and where it had problems.

Advantages of Astrolabe
Helped find time and direction Applicable for sea travel and prayer timings Worked without batteries or electricity Taught people about stars and planets Small and easy to carry

Disadvantages of Astrolabe
Needed clear skies to work well Hard to use without training Not as accurate as modern GPS It could break easily if dropped Only worked in certain places

Torquetum

The Torquetum is an ancient analog device used by astronomers many years ago. It helped people study the stars, the sun, the moon, and the planets. The tool had metal plates and arms that could move to show the sky’s positions. It was a blend of math and art, making it easier to understand how the sky works without relying on electricity or computers.

Advantages and Disadvantages of Torquetum:-

Like many old tools, the Torquetum had some great uses, but also a few downsides. Let’s look at the simple good and bad sides of this ancient machine.

Advantages of Torquetum
Helped track stars and planets Worked without power or batteries Combined three tools in one Easy to carry and use outside Inspired later space tools

Disadvantages of Torquetum
Needed expert knowledge to use Could not give very exact results Hard to build and adjust Only valid for sky and time studies Too slow for modern needs

Kerrison Predictor

The Kerrison Predictor was an early analog computer used during World War II. It helped soldiers aim anti-aircraft guns more accurately. This machine quickly calculated the enemy planes’ trajectories so that the guns could fire at the right spot. It worked by using gears and motors to track the plane’s speed and direction in real-time.

Advantages and Disadvantages of Kerrison Predictor:-

Like every innovative tool, the Kerrison Predictor had its strengths and its limitations. It helped save lives during war, but it also had some downsides. Let’s examine both sides to gain a better understanding.

Advantages of Kerrison Predictor
Improved aiming for anti-aircraft guns Worked in real time during battle Easy to use by trained soldiers Helped protect cities and armies Made quick and accurate decisions

Disadvantages of Kerrison Predictor
It could only be used for one purpose Needed regular care and repair Not useful outside of war Heavy and not easy to move Outdated once digital tools arrived

Norden Bombsight

The Norden Bombsight was a special tool used in airplanes during World War II. It helped pilots drop bombs more accurately by using speed, height, and direction. This analog computer utilized small gears and gyroscopes to perform quick calculations while flying. At that time, it was a significant aid in aiming bombs at the correct spot from the sky.

Advantages and Disadvantages of Norden Bombsight:-

Like every tool, the Norden Bombsight had both its strengths and weaknesses. It made bombing more accurate, but it was not perfect. Let’s examine what it did well and where it had issues.

Advantages of Norden Bombsight
Improved bombing accuracy Helped save fuel and time Reduced risk to pilots Easy to use once trained Worked well with aircraft systems

Disadvantages of Norden Bombsight
Did not work well in bad weather Needed skilled users It could break easily during combat Expensive to build and repair Not always accurate in real battles

Castle Clock

The Castle Clock was an intelligent machine created by Al-Jazari, a Muslim engineer, in the 13th century. It was more than just a clock; it could show time, move figures, and even play sounds. It used water and gears to work. This remarkable invention is one of the oldest examples of an analog computer, used to display time and events simultaneously.

Advantages and Disadvantages of Castle Clock:-

The Castle Clock was a great idea for its time. It demonstrated how machines could perform more than one task simultaneously. But like all tools, it had some strong and weak points. Let’s see both sides.

Advantages of Castle Clock
Showed time in a fun and straightforward way Used water power, no need for electricity Combined art and engineering Inspired future clocks and machines Showed different events during the day

Disadvantages of Castle Clock
Very complex and demanding to build Needed regular care and cleaning Not easy to move or fix Could not work without water flow Not suitable for fast or modern timing needs

Tide Predicting Machine

The Tide Predicting Machine is a specialized analog computer designed to predict the rise and fall of ocean tides. It used gears, wheels, and pulleys to solve math problems related to the moon, sun, and gravity. These machines helped sailors, port workers, and scientists determine when the tides would be high or low, which was crucial for safe travel and shipping.

Advantages and Disadvantages of Tide Predicting Machine:-

Like all machines, the Tide Predicting Machine had both strengths and weaknesses. It was helpful for many years, but it also had some limits. Let’s take a quick look at what it did well and where it fell short.

Advantages of Tide Predicting Machine
Predicted tides with good accuracy Helped in planning safe sea travel Worked without electricity Used real-time data from the moon and the sun Useful for ports and naval missions

Disadvantages of Tide Predicting Machine
Very heavy and large Could not handle sudden weather changes Needed experts to operate Only focused on tide prediction Replaced by digital tools later

Mechanical Calculator

A mechanical calculator is a machine that was used to perform mathematical calculations before electronic calculators were invented. It utilized gears, wheels, and buttons to perform addition, subtraction, multiplication, and division operations on numbers. People used it in offices, schools, and scientific work. It made math faster and easier without using electricity.

Advantages of Mechanical Calculator
Easy to use for basic math No need for electricity Durable and long-lasting Helped in schools and offices Good for learning simple calculations

Disadvantages of Mechanical Calculator
Could not solve complex problems Slow compared to digital calculators Heavy and not easy to carry Needed manual effort to work No memory or display screen

Analog Oscilloscope

An analog oscilloscope is a tool that shows electrical signals as waves on a screen. It helps people see how electricity moves through wires or devices. Engineers and scientists use it to verify that machines are functioning correctly. It’s like a window that shows what electricity is doing in real time.

Advantages and Disadvantages of Analog Oscilloscope:-

Every device has its pros and cons. Analog oscilloscopes were helpful in many ways, but they also had some limits. Let’s look at the simple pros and cons of this tool.

Advantages of Analog Oscilloscope
Shows a real-time signal instantly Easy to use and understand for the basics Great for fast signal changes Works without needing a computer Affordable and strong for lab use

Disadvantages of Analog Oscilloscope
No memory to save data Hard to measure slow signals Not suitable for complex tasks Can not store or share waveforms Needs manual settings often

Analog Sound Processor

An Analog Sound Processor is a device that changes or improves sound using real electrical signals. It works by shaping sound waves, allowing for music to be made louder, softer, or clearer. Before digital sound tools, these processors were used in radios, music studios, and movie systems. They helped control how the sound felt to our ears.

Advantages and Disadvantages of Analog Sound Processor:-

Analog Sound Processors were very useful in the past. They gave sound a warm and natural feel. However, they also faced some issues that led people to switch to digital tools later. Let’s see the good and bad points.

Advantages of Analog Sound Processor
Gives a warm and natural sound Works in real-time Easy to use with simple controls No need for computers Loved by music artists and studios

Disadvantages of Analog Sound Processor
Hard to store or copy sound Can lose quality over time Not easy to fix or upgrade Needs more space and power Less flexible than digital tools

Librascope

Librascope was a company in the United States that made special analog computers in the 1950s and 1960s. The military primarily used these computers for tasks such as flying airplanes and guiding missiles. Librascope machines could handle numerous complex calculations in real-time, which enabled fast and informed decisions during missions.

Advantages and Disadvantages of Librascope:-

Librascope computers were highly beneficial for defense and flight systems. However, just like any other old technology, it had both its advantages and disadvantages. Let’s take a quick look at them.

Advantages of Librascope
Helped guide airplanes and missiles Worked fast in real time Useful for defense and military tasks Strong and built for demanding conditions Improved safety during flights

Disadvantages of Librascope
Only used by experts and the military Very expensive to build and run Hard to move huge machines Needed regular maintenance Replaced later by digital computers

Commonly Asked Questions About Analog Computers

Many people get curious when they hear about analog computers. Since these machines are not common today, it’s natural to have questions. In this section, we will answer some of the most asked and simple questions to help you understand analog computers better in a fun and easy way.

What is an analog computer?

An analog computer is a machine that solves problems using real-world values, such as speed, temperature, or pressure, instead of numerical values.

How is an analog computer different from a digital computer?

Analog computers use signals from the real world. Digital computers use only binary numbers, represented by 0s and 1s.

Who used analog computers?

Scientists, engineers, and the military used them for complex calculations before digital computers became widely available.

Are analog computers still used today?

They are rare now. Most people use digital computers. However, some industries still utilize analog tools for specialized work.

Why were analog computers important?

They helped solve big problems in science, war, and space when digital machines were not strong enough.

Can I build a simple analog computer at home?

Yes! Some simple analog computers, such as sliders or circuits, can be constructed for fun or educational purposes.

What is the most famous analog computer?

The Antikythera Mechanism from ancient Greece is one of the oldest and most famous analog computers.

What are examples of analog computers?

Examples include the Slide Rule, Pedometer, Astrolabe, and Differential Analyzer.

Are analog computers accurate?

They were suitable for quick estimates, but digital computers give more accurate answers.

Why should I learn about analog computers today?

They teach us how people solved problems before digital tech, and they show the power of creative thinking.

Conclusion

Analog computers were the intelligent machines of the past. They helped people solve big problems using real-world values like speed, heat, or pressure. Even though we now use digital computers, learning about analog ones shows us how far we have come. From the Slide Rule to the Antikythera Mechanism, each device played an important role in history. These machines demonstrate that innovative thinking does not always require screens or codes; sometimes, it simply needs clever ideas and straightforward tools.

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