# Essay on inside of a computer

Submitted By naijababes_23
Words: 4195
Pages: 17

Topic: The Inside of a Computer

Introduction
This page introduces you to the basic concept of a computer and the inside of a computer for more research work would be discussed in other pages. This report would define computer, the processor which includes the central processing unit (CPU), and cache. Also we have the memory which is divided into the primary and secondary memory. The main primary memory includes the RAM and ROM while the secondary memory is divided into two which include the magnetic and optical device.
In addition to the processor and the memory, we will be discussing input and output of the computer. Examples of some input device are the keyboard, microphone, joystick and many others while some examples of the output device are printer, projector, speakers and many others. The introduction would be describing the Von Neuman model.
A computer is defined as a machine “whose actions are ruled by programs (Rob Williams 2000). According to Von Neuman (1958 pg3) in an analogy machine numbers are represented by an appropriate active measure whose digits is deliberated in pre assigned unity. Again Neuman(1958 pg37) wrote out a principle of direct addressing which he said “ every word in a memory has a numerical address of its own which distinguishes it and its pose within the memory. Von Neumann was also known for his contributions to the foundations of quantum mechanics and fields of mathematical logic.Below is a diagram of the Von Neuman model.

Processor
CPU
A processor can be defined as a personal computer or a small device it can also be called the microprocessor (Larry and Nancy 2004). A motherboard is in shape of a “rectangular card containing electrical circuit which the processor is mounted on, it is also an example of a circuit board” (Norton 2005 pg28). The main component of the processor is the CPU (central processing unit) which is also called the brain of the computer. The most important function of the processor is to “execute programs that are stored in the main memory taking instruction, observing them and executing them one after the other” (Andrew 2005 pg51). The CPU components are “connected by the bus which is a collection of parallel wires for transferring data, control signals and address” (Andrew 2005). Also “buses can be extraneous to the CPU connecting the memory and the I/O devices” (Andrew 2005).

fig1: CPU

ALU
Arithmetic logic unit also known as ALU is a part of the CPU which carries out the mathematical operation. This includes group of registers which uses the register to hold data which are being used for calculations. For example loads a calculation from the memory to the registers then into the ALU. This might tell the ALU if the numbers needcalculation which is an arithmetic operation or if the numbers are equal which is a logical operation (Peter 2005pg190).
In addition the CPU is formed with loads of distinct parts. The control unit has the ability of collecting instructions for the memory the ALU (arithmetic logic unit performs the operations. For example additions.

I/O device

Bus

fig2: CPU
The diagram above shows a simple computer with two I/O devices. A CPU can also hold a little amount of high-speed memory which is use for storing temporary findings or useful information. The memory is made up of registers which all have different functions. A register according to (Andrew 2005 pg52) “can be read and also written at high speed”. There are two most important registers and they are program counter (PC) and the instruction register (IR).
Fetch Execute Cycle
The CPU fetch cycle according to (Whitney 2011) it’s an order “where by instruction within a program is read into the CPU form the program memory”. During a fetch phase the instruction is read from the memory and translated by the control unit (CU). It was also mentioned by (Whitney 2011) that during execute stage the CU yields or renders the entire signal important