Computer Basic Organization- Storage Unit

Computer Basic Organization-

Storage Unit

             The data and instructions, which are entered into the computer system through input units, have to store inside the computer, before the actual processing starts. Similarly the results produced by the computer after processing, must also be kept somewhere inside the computer system, before being passed on the output units, Moreover, the intermediate results produced by the computer, must also be preserved for ongoing processing and instructions, space for intermediate results, and space for the final results.

In short, the specific functions of the storage unit are to hold (store)

1. The data and instructions required for processing (received from input devise).

2. Intermediate results of processing.

3. Final results of processing. Before these results are released to an output device.

The storage unit of all computers is comprised of the following two types of storage:

Primary storage: 

                                                                                                     The primary storage, also known as main memory, is used to hold pieces of program instructions and data, intermediate results of processing and recently produced results of processing, of the job(s), which the computer system is currently working on.

These pieces of information are represented electronically in the main memory chip’s circuitry, and while it remains in the main memory, the central processing unit can access it directly at a very fast speed However; the primary storage can hold information only while the computer system is on. As soon as the computer system is switched off or reset, the information held in the primary storage disappears. Moreover, the primary storage normally has limited storage capacity, because it is very expensive. The primary storage of modern computer system is made up of semiconductor devices.

Secondary storage:

The secondary storage also known as auxiliary storage is used to take care of the limitation of the primary storage.

That is, it is used to supplement the limited storage capacity and the volatile characteristic of primary storage. This is because secondary storage is much cheaper than primary storage, and it can retain information even when the computer system is switched off or reset. The secondary storage is normally used to hold the program instruction, data and information of those jobs, on which the computer system is not working on currently, but needs to hold them for processing later. The most commonly used secondary storage medium is the magnetic disk.