IT course work due 22/09/08

System unit components

Processors and options:
The central processing unit (the CPU is housed in a single chip called a microprocessor) is considered the brain of the computer. It is sometimes referred to as the processer. Most calculations take place in the CPU. In terms of computing power the CPU is the most important element of the computer system. Instructions are stored in cash memory the CPU fetches decodes and executes the instructions.
Two typical components of a CPU are the following:
The arithmetic logic unit (ALU), which performs arithmetic and logical operations. Abbreviation of arithmetic logic unit, the part of a computer that performs all arithmetic computations, such as addition and multiplication, and all comparison operations. The ALU is one component of the CPU(central processing unit).

The control unit (CU), which extracts instructions from memory and decodes and executes them, calling on the ALU when necessary. Control unit, is a typical component of the CPU that implements the microprocessor instruction set. It extracts instructions from memory and decodes and executes them, and sends the necessary signals to the ALU to perform the operation needed. Control Units are either hardwired (instruction register is hardwired to rest of the microprocessor) or micro-programmed.

Motherboard:
The motherboard is the main printed circuit board and contains the buses, or electrical pathways. Found in a computer. These buses allow data to travel between the various components that comprise a compute. A motherboard is also known as the system board, the backplane, or the main board.
The motherboard consists of the central processing unit (CPU), RAM, expansion slots, heat sink/fan assembly, BIOS chip, chip set, and the embedded wires that interconnect the motherboard components.


BIOS:
One of the most common uses of Flash memory is for the basic input/output system of your computer, commonly known as the BIOS.
The BIOS software has a number of different roles, but its most important role is to load the operating system. When you turn on your computer and the microprocessor tries to execute its first instruction, it has to get that instruction from somewhere. It cannot get it from the operating system because the operating system is located on a hard disk, and the microprocessor cannot get to it without some instructions that tell it how to do it.
Whenever you turn on your computer, the first thing you see is the BIOS software doing its thing, you may also see BIOS displaying information such as amount of memory.

Power supply:
If there is any one component that is absolutely vital to thecomputer, it is the power supply. Without it, the computer would not work. The power supply converts the alternating current (AC) line from your home to the direct current (DC) needed by the personal computer.
Today the power source we use is an ATX-based power supply.


Fan and heat sink:
The fan is activated when the computer system reaches a certain temperature and cools down the system to prevent overheating and any damage.
These can be located in the front and the back of the computer casing and can also be on the actual processor.

Internal memory (RAM, ROM, cache):
ROM
Read-only memory (ROM) these chips are located on the motherboard. The ROM chips contain instructions that can be directly accessed by the CPU.
Basic instructions for starting up the computer and loading the operating system are stored in ROM. ROM chips retain their contents even when the computer been turned off and has no power running through it.

RAM
Random access memory (RAM) is the temporary storage for data and programs that are being accessed by the CPU. RAM is volatile memory, which means that the contents is lost when the computer is shut down and has no power going to it.
The more RAM computer the computer has, the more capacity the computer has to hold and process large programs and files, and it also increases the system performance.



Operating systems Windows Vista and Windows XP

Vista
Vista is very resource hogging and requires a lot of ram and a good CPU. Windows vista is only good if u have at least one GB of RAM and a good graphics card. Vista is a better option as vista home premium comes with an inbuilt multimedia system it also has Sophisticated graphics. Windows vista has Improved security so it is more secure than XP security it also has better search and organization tools, it is easer to access information and applications it also has Improved system tools for backups, updates, and more

Windows XP is a better option for gaming. Windows XP is faster in gaming and running application. XP Home has several benefits over earlier versions of Windows like 95, 98. XP Home is generally more stable than previous versions, and the new interface used in XP Home makes XP easier for most people to use.One key benefit of XP Home over earlier versions of Windows is improved security. The Windows Security Center, Automatic Updates, and the Windows Firewall are all new in XP. They all help to ensure a safer computer, particularly when online.