Aviva Directory » Computers & Internet » Systems & Hardware » Hardware Components

The four main components of a computer are the central processing unit (CPU), memory, input units, and output units. These components are connected through a system bus, which passes information between them.

These facilitate the four main functions of a computer: input, processing, output, and storage, although not in the same order.

The CPU is a microprocessing chip (microchip) which, although small, functions as the brain of the computer, as the CPU is responsible for executing computer programs. A program is a set of instructions as to how to accomplish a specific task, however simple or complex.

The microchip known as the CPU is an integrated circuit that includes billions of transistors that serve as tiny on/off switches.

The CPU is considered to be hardware because it is made of silicon or some other semiconducting material.

The CPU connects to the motherboard, which is the main circuit board of the computer. Through a power source, electrons flow through pathways that are etched onto the motherboard. Other circuit boards are plugged into the motherboard or integrated with it, while other components attached to it include, besides the CPU, RAM chips, ROM chips, the system bus that connects the CPU to the main memory and other components. The hard drive, video cards, sound cards, and other components also connect to the motherboard, which includes ports and expansion slots for that purpose.

The CPU controls parts of the computer and executes the instructions of computer programs, both system programs, and other applications, processing these instructions in binary, also known as machine language, which uses 0s and 1s. The chief functions of a machine cycle are fetch, decode, execute, and store, which the CPU does according to the instructions it receives.

The main components of the CPU are the control unit (CU) and the arithmetic logic unit (ALU). The CU controls and routes data traffic, and decodes and executes program instructions, while the ALU is responsible for calculations, logical comparisons, and other mathematical functions.

Several companies produce CPUs, the largest of which may be Intel and AMD.

There are two main types of memory: cache and random access memory (RAM). Cache refers to memory that is on the CPU chip and designed to make the computer run faster, while RAM consists of chips plugged into the motherboard. RAM may be known as DRAM, for dynamic RAM, because it requires a constant supply of electrical power. The cache is SRAM, or static RAM because it does not have to be refreshed with power; therefore it is faster.

Instructions and other data are stored in cache and RAM. Cache stores the routine or anticipated instructions for the computer. When executing a program, the computer will first look to cache memory because it's much faster. If it doesn't find what it needs there, it will turn to RAM.

RAM is stored in modules or banks of chips that are plugged into the motherboard. RAM is a temporary storage area where data can be stored only as long as there is power going to the computer. Programs and data currently in use by the computer are stored in RAM, beginning with the instructions for the operating system, and any programs that are currently running. When the RAM gets full, the computer slows down, so adding more RAM to a computer can speed it up. Several companies produce CPUs, the largest of which may be Intel and AMD.

Read-only memory (ROM) chips are also located on the motherboard. This is where the basic input-output system (BIOS) is stored. The BIOS contains the start-up programs for the computer. It recognizes and manages any devices that are properly attached to the computer, such as the keyboard and mouse. The BIOS can be read but it cannot be erased or edited by the user, although there are PROM chips that are programmable after manufacture. Several companies produce CPUs, the largest of which may be Intel and AMD.

When the computer is powered up, it gets its startup instructions from the BIOS. Then it looks for the operating system (OS), which is permanently stored on the device. It then loads the necessary instructions from the OS into RAM. When you boot an application, such as a calculator, the computer gets the instructions for that program from storage and loads the instructions into RAM.

Devices used to feed information to the computer, such as a keyboard, are input units. Output units are those that the computer uses to relay information to the user, such as the monitor.

The system bus is the communication path between the major components of the computer system. It consists of cables, etchings, and connectors that carry information between the components of the computer.

Basically, the computer components are all of the hardware pieces that are inside and part of the computer itself, as well as the core input/output devices.



Recommended Resources

Search for Hardware Components on Google or Bing