Meaning of Digital Computer
A digital computer is a machine that stores data in a numerical format and performs operations on that data through mathematical manipulation.
This type of computer generally includes some type of device for storing information, some method for input and output of data, and components that allow mathematical operations to be performed on the stored data. Digital computers are almost always electronic, but they don’t necessarily have to be.
Most computers operate using binary code and could be considered digital.
There are two main methods of modeling the world with a computing machine. Analog computers use some physical phenomenon, such as electrical voltage, to model a different phenomenon and perform operations by directly modifying the stored data.
However, a digital computer stores all data as numbers and performs operations on that data arithmetically.
Most computers use binary numbers to store data, since the ones and zeros that make up these numbers are easily represented by simple on-off electrical states.
Digital computers store data in numerical format.
Computers based on analog principles have advantages in some specialized areas, such as their ability to continuously model an equation.
However, a digital computer has the advantage of being easily programmable. This means that they can process many different instruction sets without having to physically reconfigure them.
Circuit paths on a digital computer can now be printed close together.
The first digital computers date back to the 19th century. An early example is the analytic engine theorized by Charles Babbage. This machine would have stored and processed data mechanically.
However, that data would not have been stored mechanically, but rather as a series of digits represented by discrete physical states. This computer would have been programmable, the first in computing.
The first analog computers used to occupy entire rooms.
Digital computing became widespread during the 20th century. The pressures of war led to great advances in the field, and electronic computers emerged from World War II.
This type of digital computer typically used sets of vacuum tubes to store information for active use in computing. Paper or punch cards were used for long-term storage. Keyboard input and monitors emerged at the turn of the century.
Digital components such as processors are often more versatile than analog ones.
At the beginning of the 21st century, computers are based on integrated circuits instead of vacuum tubes. They still use active memory, long-term storage, and central processing units. Input and output devices have multiplied enormously, but still serve the same basic functions.
In 2011, computers are beginning to push the limits of conventional circuitry. Circuit paths in a digital computer can now be printed so close together that effects such as electron tunneling must be taken into account.
Working on digital optical computers, which process and store data using light and lenses, can help overcome this limitation.
Nanotechnology may lead to an entirely new variety of mechanical computing. Data can be digitally stored and processed at the level of individual molecules or small groups of molecules.
A staggering number of molecular computing elements would fit into a comparatively small space. This could greatly increase the speed and power of digital computers.
Inventor Charles Babbage conceived the idea of the steam-powered difference engine in 1822.