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‘Memory’ receives instructions and data from the input devices and stores them till they are needed by
other parts of the computer. Once the instructions are executed, the results are transferred to a permanent
location which are then stored in a storage device.
Memory can be classified into two types:
l Primary Memory l Secondary Memory
Memory & Storage Devices
Primary Secondary
Flash Memory
Magnetic Optical
storage
RAM ROM CD Flash drive
Hard disk
DVD Flash memory
Blu-ray disc Memory Stick
Primary Memory
Primary Memory is also known as ‘Main Memory’. It is that part of the CPU which stores the data and
instructions that are meant for current processing or for the internal management of the computer. It has
a limited capacity for storage of data.
Primary Memory can be classified into two groups:
l RAM (Random Access Memory) l ROM (Read Only Memory)
RAM
It holds the information temporarily, during the ongoing operation of a computer. When a computer is
under operation, the data or instructions come into its memory for instant access from the secondary
memory. During the course of the execution of instructions, some
intermediate results may be produced which are stored in the RAM.
RAM is a volatile memory i.e. when a computer is switched ‘OFF’ or
the power supply is interrupted, all the information stored in it gets
disappeared or lost. RAM chip is made of Metal Oxide Semiconductor
(MOS). RAM is available in the form of chips of different capacities, E.g.,
4 GB, 8 GB, 16 GB, 32 GB, 64 GB, etc. You can upgrade the capacity of existing RAM in a computer by
installing extra RAM chips in addition to the existing ones. There are different types of RAM like SRAM,
DRAM, SDRAM, EDRAM, ECRAM, etc.
Basics of Information Technology 25

