In the above section we have seen various types of semiconductor RAMs. These high speed semiconductor storage devices (i.e. RAMs) are expensive. So we need some inexpensive media for storage. Also semiconductor memory has the following limitations:
1) Limited Capacity: Semiconductor (primary) memory of today?s computers is not sufficient, since most of the data processing organizations deal with a large volume of data.
2) Volatile Memory: Semiconductor memory is volatile in nature. But there is always a need to store data on a permanent basis.
Thus there is a need of additional memory, that is inexpensive, non-volatile in nature and has large capacity. Magnetic material is inexpensive and long lasting, so it is an ideal choice for us. Magnetic memory is a permanent non-volatile, type of memory.