HK Computer Technology

What is a Computer Memory and Their Types?

The computer’s memory stores information, directions needed throughout the process of data, and output results. Storage could also be needed for a restricted amount of your time, instantly, or, for associate extended amount of your time. differing kinds of reminiscences, every having Its own distinctive options, area unit accessible to be used during a laptop. The cache memory, registers, and RAM area unit quickly reminiscence and store the information and directions briefly during the process of information and directions. Secondary memory like magnetic disks and optical disks have massive storage capacities and store the information and directions permanently, however, area units are slow memory devices.

The reminiscences area unit is organized within the laptop in a manner to attain high levels of performance at the minimum value. during this lecture, we tend to discuss different kinds of memories, their characteristics, and their use within the laptop.

Computer Memory can be classified basically into three types:

• Primary Memory
• Secondary Memory
• Cache Memory

Primary Memory

It is conjointly referred to as because of the Main Memory or Internal Memory. It stores the info for the process and the Program directions. it’s conjointly the Immediate Access Memory. it’s temporary memory and of restricted capability. the quality base capability for Primary memory starts from 640 KB, 1MB, 2MB, 8MB, 128MB, 256MB, 1GB, 2GB, 4GB, etc. (in multiples of 2). reckoning on the requirements of the user.

Functions of Primary Memory:

• It holds the OS directions whereas the pc is booting.
• It briefly holds the input directions from the input devices whereas the information is being input and processed.
• It stores the results briefly till it’s transferred to the individual output devices.

Types of Primary Memory

• • RAM – Random Access Memory
  • Static RAM
  • Dynamic RAM

ROM – Read Only Memory

• • PROM – Programmable Read Only Memory
  • EPROM – Erasable Programmable Read Only Memory
  • EEPROM – Electronic Erasable Programmable Read Only Memory

RAM – Random Access Memory

It is a read/write memory. knowledge is kept by addressing one RAM cell. the info and programming directions fed via the device are kept within the RAM quickly till that program is employed. RAM could also be updated.

There are two types of RAMs

• Static RAM – It retains the stored information until the computer is working.
• Dynamic RAM – It retains stored information only until the program is working and loses the information once the program execution is completed.

ROM – Read Only Memory

It is a permanent memory. The directions will solely be scanned by the pc. The directions associated with system operations are kept here. These directions are written by the manufacturer and can’t be amended by the user. once the system is turned ON, ROM directions are instantly dead and employed in the operation of all I/O devices.

There are three types of ROM

• PROM – Programmable Read Only Memory
• EPROM – Erasable Programmable Read Only Memory
• EEPROM – Electronic Erasable Programmable Read Only Memory

PROM (Programmable Read Only Memory)

It is a non-volatile memory. Instructions can be written once by the programmer and then subsequently read.

EPROM (Erasable Programmable Read Only Memory)

It is an associate degree improvement over the promenade chips. directions may be rewritten by the applied scientist victimization special techniques. The directions area unit erased victimization ultraviolet radiation ultraviolet illumination|UV|actinic radiation actinic ray} light and rewritten. to vary the directions the chip has got to be aloof from the machine so swap when the changes are created.

EEPROM (Electronic Erasable Programmable Read Only Memory)

It is an advancement over read-only memory, and therefore the chip needn’t be taken out from the machine. Instead, the programming is a finished exploitation software package. These chips are utilized in location (POS) terminals to record worthwhile connected data and may be updated as and once required. but they’re pricey compared to the traditional read-only storage chips.

Secondary Memory

This type of memory is additionally referred to as external memory or non-volatile. it’s slower than the main Memory. These square measures are used for storing data/Information for good. Contents of secondary reminiscences square measure 1st transferred to main memory, and so the processor will access it. For example, disk, CD-ROM, DVD, HDD, Pen Drive USB, etc.

Characteristics of Secondary Memory

• These are magnetic and optical memories
• It is known as backup memory.
• It is non-volatile memory.
• It is used for the storage of data on a computer.
• The computer may run without secondary memory.
• Slower than primary memories.

Cache Memory

Cache memory could be a terribly high-speed semiconductor memory that may speed up electronic equipment. It acts as a buffer between the electronic equipment and the main memory. The components of knowledge and programs square measure transferred from disk to cache memory by OS, from wherever electronic equipment will access them.