Computer memory is one of the important and compulsory components of every computer system. This lecture describes memory and memory devices used to store date and programs on a temporary or permanent basis for use in digital computers. The two main types of computer memory i.e. primary and secondary memories are discussed thoroughly.

Objectives

• Define bit, byte, memory word and memory unit 
• Differentiate between main memory and secondary memory.
• Explain the chip memory and magnetic memory. 
• Differentiate between volatile and non-volatile memory 
•  Internal Processing memory, RAM and ROM 
• Sequential access and direct access of memory 
• Magnetic tapes, magnetic disks and optical disks

Key Points

• Computer memory is a storage device that holds instructions, data and the results produced after processing by the computer. 
• Main memory is high-speed IC chip memory that stores programs and data that the computer is currently executing. 
• Cache memory is small amount of high-speed semiconductor memo y, which exists inside the microprocessor and it is faster than main memory 
• Registers are small memory units inside the processor, used to temporarily store binary information and pass it on to the other parts of the processor or main memory during execution of instructions 
• ROM is Read Only-Memory used to store small programs that are frequently required and are not to change during the operation of the computer 
• Secondary memory, also known as backing storage. has huge storage capacity and stores information permanently 
• Optical disk is a plastic-coated disk that can store date in digital form using laser technology aa tiny bumps etched on the surface 
• Flash memory is a type of EEPROM it is solid-state storage device having no moving parts end used as hard disk

Referenced Material