Table of Contents
Components of a computer system
A computer basically performs five major operations or functions such as :
- Accepts data or instructions by way of input.
- Stores data,
- Processes data as required by the user,
- Gives results in the form of output, and
- Controls all operations inside a computer.
Each of these operations are discussed and shown in the figure given below:
Let us know the details of basic computer operations.
1. Input
This is the process of entering data and programs in the computer system. Therefore, the input unit takes data from us to the computer in an organized manner for processing.
2. Storage
The data and instructions are saved/ stored permanently in storage unit. The storage unit performs the following major functions:
- All data and instructions, before and after processing, are stored here.
- Intermediate results of processing are also stored here.
3. Processing
The task of performing operations like arithmetic and logical operations is called processing. The Central Processing Unit (CPU) takes data and instructions from the storage unit and makes all sorts of calculations based on the instructions given and the type of data provided. After this data is sent back to the storage unit.
4. Output
This is the process of producing results from the data for getting useful information. The output produced by the computer after processing is stored inside the computer before it is given to you in human readable form. The output is also stored inside the computer for further processing.
5. Control
Controlling of all operations like input, processing and output are performed by control unit. It takes care of step by step processing of all operations inside the computer.
In order to carry out its operations, a computer system is divided into three separate units. They are: 1) Arithmetic logical unit, 2) Control unit, and 3) Central processing unit. All these three units are known as functional units.
1. Arithmetic Logical Unit (ALU)
The processing of the data and instructions are performed by Arithmetic Logical Unit. The major operations performed by the ALU are addition, subtraction, multiplication, division, logic and comparison. For processing, data is transferred from storage unit to ALU. After processing, the output is returned back to storage unit for further processing or for storing purpose.
2. Control Unit (CU)
The next component of computer is the Control Unit, which acts like the supervisor seeing that things are done in proper way. The control unit determines the sequence in which computer programs and instructions are to be executed. Activities like processing of programs stored in the main memory, interpretation of the instructions and issuing of signals for other units of the computer to execute them are carried out by CU. It coordinates the activities of computer’s peripheral equipment which include input and output devices. Therefore, it is the manager of all the operations mentioned in the previous section.
3. Central Processing Unit (CPU)
The ALU and the CU of a computer system are jointly known as the central processing unit( CPU) . You may call CPU as the brain of any computer system. It is just like brain that takes all major decisions, makes all sorts of calculations and directs different parts of the computer functions by activating and controlling the operations. The CPU (Central Processing Unit) is the device that interprets and executes instructions.
A computer system includes a computer, peripheral devices, and software.
System Concept
A system is a group of integrated parts that have the common purpose of achieving some objectives. A system has following three characteristics:
- A system has more than one element.
- All the elements of a system are logically related.
- All the elements of a system are controlled in such a way that the system goal is achieved.
Since a computer is made up of integrated components (input and output devices, storage, CPU) that work together to perform the steps called for in the program being executed, it is a system.
A computer is a device capable of accepting information or data, processing the information, and providing the results as an output.
As computer is a machine, it has no intelligence & is just hardware. Basically computer system is a combination of five elements without them it cannot work.
- Hardware – machine part.
- Software – instructions to hardware to perform a task.
- People – To operate hardware, create software.
- Procedures – It is a set of instructions.
- Data/Information -Data is a raw material, e. unevaluated facts & figures. Information is the processed data.
Motherboard
The motherboard is the main circuit board of your computer and is also known as the main board or logic board. If you ever open your computer, the biggest piece of silicon you see is the motherboard. Attached to the motherboard, you’ll find the CPU, ROM, memory RAM expansion slots, PCI slots, and USB ports. It also includes controllers for devices like the hard drive, DVD drive, keyboard, and mouse.
Each motherboard has a collection of chips and controllers known as the chipset. When new motherboards are developed, they often use new chipsets.
Computer Motherboard Components
- Mouse & keyboard
- USB
- Parallel port
- CPU Chip
- RAM slots
- Floppy controller
- IDE controller
- PCI slot
- ISA slot
- CMOS Battery
- AGP slot
- CPU slot
- Power supply plug in
1. Mouse & keyboard:
Keyboard/mouse Connectors are two types basically. All PCs have a Key board/mouse port connected directly to the motherboard.
2. USB (Universal serial bus):
USB is the General-purpose connection for PC. You can find USB versions of many different devices, such as mice, keyboards, scanners, cameras, and even printers. a USB connector’s distinctive rectangular shape makes it easily recognizable. USB has a number of features that makes it particularly popular on PCs. First, USB devices are hot swappable. You can insert or remove them without restarting your system.
3. Parallel port:
Most printers use a special connector called a parallel port. Parallel port carry data on more than one wire, as opposed to the serial port, which uses only one wire. Parallel ports use a 25-pin female DB connector. Parallel ports are directly supported by the motherboard through a direct connection or through a dangle.
4. CPU Chip :
The central processing unit, also called the microprocessor performs all the calculations that take place inside a pc. CPUs come in Variety of shapes and sizes. Modern CPUs generate a lot of heat and thus require a cooling fan or heat sink. The cooling device (such as a cooling fan) is removable, although some CPU manufactures sell the CPU with a fan permanently attached.
5. RAM slots:
Random-Access Memory (RAM) stores programs and data currently being used by the CPU. RAM is measured in units called bytes. RAM has been packaged in many different ways. The most current package is called a 168-pin DIMM (Dual Inline Memory module).
6. Floppy controller:
The floppy drive connects to the computer via a 34-pin ribbon cable, which in turn connects to the motherboard. A floppy controller is one that is used to control the floppy drive.
7. IDE controller:
Industry standards define two common types of hard drives: EIDE and SCSI. Majority of the PCs use EIDE drives. SCSI drives show up in high end PCs such as network servers or graphical workstations. The EIDE drive connects to the hard drive via a 2-inch-wide, 40-pin ribbon cable, which in turn connects to the motherboard. IDE controller is responsible for controlling the hard drive.
8. PCI slot:
Intel introduced the Peripheral component interconnect bus protocol. The PCI bus is used to connect I/O devices (such as NIC or RAID controllers) to the main logic of the computer. PCI bus has replaced the ISA bus.
9. ISA slot:
(Industry Standard Architecture) It is the standard architecture of the Expansion bus. Motherboard may contain some slots to connect ISA compatible cards.
10. CMOS Battery:
To provide CMOS with the power when the computer is turned off all motherboards comes with a battery. These batteries mount on the motherboard in one of three ways: the obsolete external battery, the most common onboard battery, and built-in battery.
11. AGP slot:
If you have a modern motherboard, you will almost certainly notice a single connector that looks like a PCI slot, but is slightly shorter and usually brown. You also probably have a video card inserted into this slot. This is an Advanced Graphics Port (AGP) slot.
12. CPU slot:
To install the CPU, just slide it straight down into the slot. Special notches in the slot make it impossible to install them incorrectly. So remember if it does not go easily, it is probably not correct. Be sure to plug in the CPU fan’s power.
13. Power supply plug in:
The Power supply, as its name implies, provides the necessary electrical power to make the pc operate. the power supply takes standard 110-V AC power and converts into 12-Volt, 5-Volt, and 3.3-Volt DC power.