Q. Basic need of Random Access Memory?

Main memory is Random access memory. It is generally organised as words of fixed length. Length of a word is termed as word length. Every one of these memory words has an independent address and every one of them has same number of bits. Generally total numbers of words in memory are some power of 2. A number of typical memory word sizes are 8 bits, 16 bits, 32 bits etc. Main memory can be both read and written into so it is known as read-write memory.

The access time and cycle time in RAMs are constant and independent of location accessed. How does this happen? To answer this, let's first discuss how a bit can be stored using a sequential circuit. Logic diagram of a binary cell is displayed in Figure below:

Figure: Logic Diagram of RAM cell