A signal that is discrete in terms of both time and amplitude is called a digital signal. Digital data can be represented by two states: ‘high’ or ‘1’ state and ‘low’ or ‘0’ state. Digital computers process the binary input and provide the user with the desired output. Digital computers are faster, more accurate, have high precision, and provide enormous data storage. Electronic Numerical Integrator and Computer (ENIAC) was one of the first digital computers.
Types of Digital Computers
On the basis of size, digital computers can be broadly classified into four categories:
1. Micro Computer
The personal computers, laptops, tablets, and mobile phones that we use in our daily life fall under the category of microcomputers. These type of computers consist of microprocessor and various input/output devices embedded on a printed circuit board. They are less complex and comparatively inexpensive. Microcomputers are advantageous because they are flexible, portable, and loaded with features.
2. Mini Computer
Minicomputers are most popular for their quality of multiprocessing. It means that mini computers can use multiple processors connected to a common memory and the same peripheral devices to perform different tasks simultaneously. Minicomputers have greater complexity than microcomputers. These are also known as mid-range computers and are generally used for applications like engineering computations, data handling, etc.
3. Mainframe Computer
Mainframe computers were first introduced during the early 1930s and were properly functional in the year 1943. They are known for their exceptional data handling capacity and reliability. This quality is used in applications where bulk data handling and security is the main concern. For example, banks, census, etc. Harvard Mark 1 was the first mainframe computer.
4. Super Computer
Supercomputers are basically used in scientific and research-related applications. They require an entire room for their set up and operation. Supercomputers employ thousands of processors that work together to perform trillions of calculations per second. Therefore, they require external cooling pipes to manage the generated heat. They are fast, accurate, and secure. Some of the prominent organisations that make use of supercomputers are the National Nuclear Security Administration, NASA, ISRO, etc.
Examples of Digital Computers
A digital calculator is an electronic gadget designed to perform calculations including simple mathematics, complex algebra, logical analysis, etc. Most digital calculators are easily portable and battery-powered. Computers were initially designed to perform calculations. Hence, an electronic calculator is the most significant example of a digital computer.
2. Digital Clock
Digital clocks display the time on the screen directly in terms of numeric digits, that are easy to comprehend. They are inexpensive and offer better accuracy. However, the timekeeping mechanism of both analogue and digital clocks is almost the same. Both of them make use of quartz crystal. The crystal vibrates for 32,768 times to generate a pulse which is then fed to 15 flipflops in order to generate a 1 Hz signal. A digital clock makes use of integrated circuits that deal with digital data. Hence, a digital clock is the most obvious digital computer we use in daily life.
3. Weighing Machine
A digital weighing machine consists of a sensor, a microcontroller and a digital display screen. Most of the digital weighing machines are battery-powered making them easily portable. The sensor senses the pressure and generates a change in resistance. This change in resistance is then fed to the microcontroller that processes and converts the signal to human-understandable digital digits.
4. Consumer Electronic Equipments
Consumer electronic equipments are the electronic gadgets that we use in daily life. For example, a microwave oven, refrigerator, washing machine, vacuum cleaner, etc. These daily life devices make use of digital computing, therefore, can be listed under the category of digital computers. Modern refrigerators make use of Digital Invertible technology that allows the compressor to adjust the cooling speed as per the requirement. Similarly, microwave ovens have built-in digital counters and temperature sensors that offer better functionality compared to traditional ovens. Likewise, automatic washing machines have a microcontroller chip that controls all the processes and data to generate the required output. A large portion of our life is dependent upon digital computers.
A lot of operations performed inside an automobile are digital computer-dependent. For example, accessing GPS, playing music, wielding the smart rearview mirror, etc. Hence, the next time you operate any such feature, get yourself reminded of the digital computers, its types and applications.
5. Smart Phones
Smart phones have become a gadget of prime importance to all of us. A lot of our daily life tasks depend on smart phones. A smart phone is a micro computer that consists of a processor, a memory element and various input/output devices embedded on a printed circuit board. The processor takes the real-life input from the user, converts it into digital form, processes it, and output the data into user understandable format.
6. Laptop/Personal Computer
With the advancement in technology, a lot of devices have switched to digitization. Earlier, personal computers worked on analogue technology. Therefore, they were slow, less precise, and offered low signal quality. But, digital computers helped overcome all these disadvantages along with providing additional features such as portability, better information storage, greater flexibility, etc.
Automatic Teller Machine is a perfect example of mainframe computers. Data handling capacity and reliability are the two most notable traits of mainframe computers. This is why they are employed in applications where security and flawless operation are prime concerns.