Digital Systems are made up of various components. Namely,
- Input Unit
- Central Processing Unit (CPU)
- Memory
- Secondary Storage
- Output Unit
- Input Unit:
Input Unit comprises of various Input Devices that are used to input data, give instructions to the Computer.It receives input from the input devices and converts it to the binary from and sends it to the central processing unit for processing. The primary input devices of Computer is Keyboard. Other Input devices that do not require any sort of typing as in Keyboard are also available, called pointing devices.Pointing devices gives input to the Computer by Point and click , drag and drop, double click, Scroll Fashion. Some of the pointing devices are mouse, Light pen, etc. Most famous input device among the gamer's out there is joystick.
- Central Processing Unit (CPU):
Also called the brain of the computer system, An CPU controls all the operations and the peripherals connected to the computer system like the brain we have.The CPU receives raw data as input through input devices , Processes them as per the instructions given, stores the result in the memory for future reference and sends the result to the Output devices for Display. The CPU is divided into 3 major Parts namely.
- Arithmetic and Logical Unit (ALU):
This part of CPU handles the Arithmetic and Logical operations of the Computer System. Arithmetic Operations such as addition, subtraction, Division and multiplications And Logic operations such as AND operations, OR operations, etc are handled by ALU. however other operations such as trigonometric operations, logarithmic operations are not handled by ALU, but by an special mathematical unit called FPU i.e. Floating Point Unit.
- Control Unit (CU):
This part of CPU controls each and every action that is performed in the computer and handles all the peripherals connected to the computer system, All the operations that are being carried out by the computer is controlled by the control unit. The control unit makes sure that each and every unit does it's job, so that the computer can perform efficiently. The Control Unit Sends control signals to all the peripherals in order to control them. Under the Control of Control Unit , the computer receives input from input devices, processes them, stores them if necessary and sends the result to the output devices for display. The Control unit makes sure that all the components are connected to each other and are working together as an single Unit i.e. an computer.
- Registers:
The CPU contains various types of Register. Registers are the high speed temporary memory that can hold small amount of data. CPU uses registers to hold memory locations of instructions and data that are need during the processing. Registers also holds intermediate data that are produced during processing such as carry or borrow's during addition or subtraction operations.
- Memory Unit (Main Memory):
This is the main memory of the computer system. This is where the CPU stores data, instructions, frequently stored programs in order to make the processing more efficient. The main memory of the computer system is also divided into two types,
Random Access Memory (RAM) :
RAM is an volatile memory in which both read and write operations can be performed. It is called an volatile memory because the data in it is stored temporarily. i.e. in case of an power failure, data stored in it is lost. Computer uses RAM to store data, instructions during processing. Hence, it indirectly affects the processing speed of the computer by affecting the speed of fetching data and instructions.
Read Only Memory(ROM) :
ROM is an non-volatile memory in which only read operations and be performed, however there are types of ROM in which read \ write operations can be performed (not in same way as RAM, but it can be reprogrammed). ROM is used to store firmware, i.e. the programs that are required to boot up the computer system. It also check for hardware and operating system during the boot. ROM are programmed by computer manufacturers during their manufacturing. Other types of ROM are PROM, EPROM, EEPROM, etc.
- Secondary Memory:
This is the secondary memory of the computer system. This part of the Digital computer is virtually unlimited, that means it can be extended as much as we want. If you have an 500 GB hard disk and isn't sufficient for you, then you can buy other storage media such as hard disks, flash drives, etc and plug it in your computer. If that's not enough, you can buy more and use it. hence the memory can be extended as much as we want.
Data, information, programs are stored in the secondary memory for future reference. We can store a huge amount of data and programs in the secondary memory for a long period of time and retrieve it easily without any problem. Some examples of Secondary Memory are Hard disks, USB drives, SD cards, Optical disks, etc.
- Output Unit:
Output Unit comprises of various Output Devices that are used to display the result of processing to the user.It receives result in binary form from the CPU and converts it to user-understandable form and displays them to user. The primary Output devices of Computer is Monitor. Other output devices of the computer system are, Printers, plotters, projectors, etc.
