Analog, Digital and Hybrid Computers
Continuous Vs Binary Signal Data Transmission
Humans perceive the world in analog, which explain why every bit of info we see, speak and hear is transmitted in continuous form. This infinite stream of information is what adds up to analog signals.
Digital transmission on the other hand discreetly estimates electric data signals using zeros and ones. Nearly all computer devices today are digital, meaning that they use binary numbers to manipulate data signals in two major states: 0 (zero) and 1 (one).
Computer data signals can be described under 3 major categories:
1: Analog Computers
Analog computers represent data and information in continuous signals with infinite values. They take advantage of mechanical, electrical and hydraulic quantities of nature to simulate problems to be solved.
When recording analog data, the output sequence is recorded in continuous rather than binary signals. Analog computers are solution oriented towards differential equations where time is the most important variable, and since they produce only continuous signals, the computed outputs do not use word length as a criteria for computation. Usually, computation and output happen simultaneously.
Analog computers were actually the first in a series of what culminated to current breeds of supercomputers and personal computers. They were used to design and test various kinds of aircraft, ICBM (Intercontinental ballistic missiles) and in numerous industrial installations.Their popularity gradually ebbed in the 1950s and 1960s as digital computers became computers of choice.
Until today, engineering and artistic research fraternity prefer using simulation to model experiments during design stages of industrial products, and the scientists in the 50s-60s turned to analog systems to bring their ideas to life.
For example, in trying to perfect the suspension system in a car design, analog systems could be used to simulate and thereby provide engineers better designs of pressure resistant suspensions. As long as experimental environments could be explained by mathematical formulae, they also could be simulated along analog computers.
Simply put, as long as experimental environments could be explained by mathematical formulae, they also could be simulated using analog models.
Analog computers have disappeared from mainstream establishments and can only be found in select research, universities and industrial facilities, and as experimental toys and tools for computer geeks.
Electronic enthusiasts still fiddle around with challenges of analog electronics because it measures real-time data to information as opposed to internal data processing in digital systems.
Analog devices are also remembered as experimental contraptions and were far from achieving what digital systems have achieved by far. Despite championing parallel processing in ways better than digital systems, they lagged behind when it came usability for ordinary users. On the contrary, digital signals from digital devices have proved easy to use and resultant data easy to manipulate and store.
This does not mean that analog devices and memorabilia are foregone in our history. It is obvious they played an important role until there arose better computation methods and the craze over personal computers. Everywhere you turn, you will find digital gadgets such as computers, digital cameras, smartphones, video games, name it.
Despite the disparities between the two technologies, it is probably safe to write that society has lived and will continue to live both analog and digital lives.
Application of Analog Computers
Unlike contemporary computers which can be used for various computing purposes at home and office, analog computers were used for industrial purposes to measure parameters that vary continuously.
Analog computers were and can be used to measure the following signal types:
Using the analog clock as a simple analogy, the minute and hour hands are constantly on the move and just by looking at the minute hand, you can visually measure time gone by or time to come without having to cycle between digits 0 to 9 as is in digital clocks.
Analog signals are continuous variables and take place simultaneously, continuously and in real-time without the need of additional computations and tools on the sides. A running analog computation process is an end in itself.
Analog Output Signals
When engineers were running tasks on an analog computer, it simulated the real world by running specified formulas and output could be read in electric voltages and various kinds of mechanical motions.
Traditional analog computers did not necessarily need storage resources as output because computation from analog computer could be read and used real-time via:
- graph plotters
- The Three Components of A Computer System
A computer system integrates three main components and these are hardware, software and humanware.
Have you used an analog computer before? If so, tell us your experience in comments
Examples of Analog Devices
- Slide rule
- Automobile speedometer
- Tide predictors
- Thermometers reading
- Analog clock
- Operational amplifiers
- Mechanical integrators
- Electric integrators that solve partial differential equations
- Norden bomb sight
- Neural networks
- Analog clock
2: Digital Computers
Digital computers as the word suggests, work by manipulating binary digits which are represented in numerals and non-numeric letters and symbols. Unlike analog computers which measure data to information in an infinite form, digital computers operate by estimating data input and output using the 0 and 1 binary mode or discrete ON and OFF electric signals.
Digital computers are designed to manipulate mathematical variables in form of numbers and are capable of delivering more accurate data than analog computers. They are designed to manipulate logical operations and arithmetic operations like multiplication, addition, subtraction and division.
In layman’s language, a digital computer is designed to process arithmetic or logical calculations automatically using binary digits.
Some of the advantages of digital computers over analog computers include versatility and accuracy and that digital computers are easily re-programmable.
Also, most information today is stored digitally in and out of the computer. If also you wish to transfer analog files like audiovisual recordings from old analog video tapes into your computer for purposes of storage and editing, you can use analog to digital converters (ADC) for this purpose.
Differences Between Analog and Digital Devices
The major difference between digital and analog computers is in the manner in which they handle data. While digital computers use binary language in order to accurately effect computation, analog computers handle continuous data such as voltage changes and temperature fluctuations to output its computation.
Work on continuous values
Work on discreet values
Measure quantities like speed and temperature
Solve mathematical problems like addition and subtraction
Preferable in engineering and scientific fields
Used by all and in all sectors of society
Special purpose computers
PCs are general purpose computers
May have no memory
Must have memory in order to operate
Use carefully written lists of instructions
Can connect different sub-systems together electrically with patch cables
Produce numbers as output
Output voltage signals, and has sets of analog meters and oscilloscopes to display the voltages
Vary in size from tiny contraptions, desktop size to multi rack equipment
Vary from tiny embedded systems to room-sized server systems
Storage is difficult because they use continuous signals
Numeric, discrete nature of digital computers makes data storage simple
3: Hybrid Computers
A hybrid computer is a combination of favored features of analog and digital computers. This should be the computer of choice if the user has to process both continuous and discrete data.
From a perspective point of view, a hybrid computer has the speed of an analog computer and the accuracy and memory of a digital computer.
For example, an analog device could be used to measure patient blood pressure and temperature in a medical facility and derived data is converted into meaningful digital data.
Most of the time, a hybrid computer is designed for specialized assignments. They are used in sensitive military installations and important buildings to monitor special activities and radar functionalities.