A Guide to Internal Memory in Computer

It is also called primary, core or main memory, is used to store data program (instructions set) needed for current processing. Also, after processing a particular job, the resulting output or intermediate output is retained in the memory for further processing if need be, before it is permanently stored in the external storage.

Internal memory is referred to as core memory because earlier component made use of core materials such as ferrite core as their memory. Currently, semi-conductors are used, such as silicon chips.

The internal or main memory can be categorized into two types of semi-conductor, namely:

Random Access Memory (RAM) - being volatile (Dynamic memory) which lose its formation immediately power is switched off:

Read Only Memory (ROM) - the non-volatile or static memory, which retain information when power is switched off.

Random Access Memory

When an instruction set (or program) is typed into a computer, they are put into the main memory. This program is stored in a part of this main memory called the RAM.

When the computer is switched off, this program will be lost or it will disappear from the RAM. To safe guide this; it is essential to make copy of the program on an external storage device (e.g. floppy disk, tape etc.) before switching off the computer. So, when next the computer is switched on, the program can be copied back into the RAM from the external device where it was earlier stored (before the switch off).

Read Only Memory

The ROM is the second type of main memory. It cannot be used to stored dynamic programs like the RAM. Its main function is to store some preset instructions, to tell the computer what to do. The instructions are permanent and non-volatile, programmed on the ROM chips by the manufacturer. The user of the computer system cannot change these instructions. The ROM is also called the firmware or pre-wired memory. The functions of ROM are stated below thus:

Tell the computer what to do when power in turned on

Check to see that the cable to the printer is connected

Interpret each key on the Keyboard to the control unit