Components Of A Computer
CPU The Central Processing Unit (also called the CPU) processes the raw data and turns it into information.
There are three main elements in a CPU:
o The control unit
o The arithmetic and logic unit
o The immediate access store
The control unit co-ordinates the input and output devices
The arithmetic and logic unit does all the calculations and makes logical decisions.
The immediate access store holds all the data and programs being used at any particular moment.
Data signals are groups of binary digits (bits) that represent characters (e.g. letters of the alphabet, numbers, punctuation marks).
Control signals are sent by the control unit to other parts of the CPU and to the input and output devices to tell them to be ready to receive data.
(RAM) Random Access Memory
· Random Access Memory is the part of the computer’s memory where programs and data are stored when they are being used.
· When the computer is switched on, the operating instructions, computer programs, and data are moved into the RAM as required.
· RAM is usually measured in megabytes.
· The more RAM a computer has, the more it can do.
· RAM empties every time the computer is switched off - this is why work has to be saved before the computer is switched off!
(ROM) Read Only Memory
· Read Only Memory is memory that is not lost when the computer is switched off.
· All computers have a small amount of ROM.
· This is so that essential instructions can be stored.
· Instructions stored in the ROM enable the computer to check the hardware and load the operating systems.