An electronic device called a computer accepts data, processes it, and outputs the desired result. It executes programmed computation quickly and accurately. Or, to put it another way, the computer receives data as input and stores the data and instructions in memory for later use. Data is processed and then transformed into information. gives the output at the end. Here, input refers to the unprocessed data that we want the machine to handle and then give us a response, output refers to the result of the machine’s processing of the unprocessed data, which may include data analysis, searching, distributing, storing, etc. Consequently, a computer data processing system is also referred to as.

What is Computer Memory?

Computer memory is identical to human memory. Data, information, and instructions are stored there. It is a data storage component or device where instructions for processing data are stored along with the data that needs to be processed. Both the input and the output can be stored in this place.

Characteristics of Computer Memory

• It is semiconductor memories.
• Compared to secondary memory, it is faster computer memory.
• A computer system cannot run without primary memory.
• The computer’s main memory is typically a volatile memory.

How Does Computer Memory Work?

A program is loaded into primary memory when you open it from secondary memory. Moving a program from a solid-state drive (SSD) to RAM is an example of how different memory and storage can be used. The opened software can communicate with the computer’s processor more quickly because primary storage is accessed more quickly. Temporary memory slots or other storage locations can easily access the main memory. Since memory is volatile, data is only stored there momentarily. When a computer is turned off, data stored in volatile memory is permanently erased. A file is sent to secondary memory for storage when it is saved.

There are numerous types of memory that are available. The type of primary memory used will have an impact on how it operates. However, memory is typically more closely related to semiconductor-based memory. Metal-oxide-semiconductor (MOS) transistors on silicon are used in integrated circuits (ICs), which make up semiconductor memory.

Types of Computer Memory

In general, computer memory is of three types:

• Primary memory
• Secondary memory
• Cache memory

1. Primary Memory

It is also referred to as the computer system’s main memory. During computer operations, it is used to store data, programs, or instructions. It is frequently referred to as semiconductor memory because it uses semiconductor technology. There are two types of primary memory:

RAM (Random Access Memory): Its memory is volatile. Information is stored in volatile memory according to the power source. The memory will lose all of its data and information if the power source fails, is interrupted, or stops. When a computer boots up or turns on, RAM is used. Programs and data that must be temporarily stored and executed by the processor are kept there. RAM comes in two varieties:

S RAM (Static RAM): Transistors are used in S RAM, and as long as power is applied, the circuits of this memory can maintain their state. This memory is made up of a number of flip-flops, each of which can store one bit. It is quicker because it has a shorter access time.

D RAM (Dynamic RAM): Using transistors and capacitors, D RAM stores data as a charge on the capacitors. They have a huge number of memory cells. After a brief period, the capacitor needs to be recharged. Compared to S RAM, this memory is slower.

ROM (Read Only Memory): This memory is non-volatile. Information is stored in non-volatile memory even if the power source fails, is interrupted, or stops. The system’s operating instructions are stored in read-only memory, or ROM. We can only read the programs and data that are stored on read-only memory because that is what its name denotes. It has a few electronic fuses that can be set to fuse for a certain piece of data. Binary-formatted data is kept in the ROM. Additionally called permanent memory. Four types of ROM exist:

MROM(Masked ROM): The first ROMs were hardwired devices with a pre-programmed set of data or instructions. This is how low-cost ROMs known as “masked ROMs” operate.

PROM (Programmable Read Only Memory): The user may make one modification to this read-only memory. The user buys a blank PROM, and then employs a PROM program to load the necessary data into the PROM. Once written, its content cannot be changed.

EPROM (Erasable Programmable Read Only Memory): With EPROM, a PROM extension, the contents of ROM can be deleted by subjecting the device to ultraviolet light for almost 40 minutes.

EEPROM (Electrically Erasable Programmable Read Only Memory): Here, the written content is electrically erasable. The EEPROM can be erased and reprogrammed up to 10,000 times. Programming and erasing both happen very quickly—between 4 and 10 milliseconds. Any area in an EEPROM can be selectively erased and programmed.

2. Secondary Memory

It is also referred to as backup memory and auxiliary memory. It serves as a non-volatile memory and can hold a lot of data and information. Secondary memory is slower than primary memory and stores data or information permanently. Secondary memory cannot be accessed directly by the CPU. The CPU can access the data/information from the auxiliary memory after it has been copied to the main memory.

Characteristics of Secondary Memory

• It is a reliable and non-volatile memory.
• It is a slow memory but reusable.
• The storage capacity of secondary memory is large.
• It is cheaper than primary memory.
• An electronic device can function without secondary memory.
• Even when the power is off, data is permanently stored in secondary memory.

Types of Secondary Memory

1. Magnetic Tapes: For magnetic recording, magnetic tape is a long, thin strip of plastic film with a thin magnetic coating on it. On tape, bits are stored as magnetic patches called RECORDS that travel along numerous tracks. Usually, 7 or 9 bits are simultaneously recorded. One read/write head is present on each track, allowing data to be recorded and read as a series of characters. It can move forward or backward, stop, or be wound around.

2. Magnetic Disks: A magnetic disk is a circular piece of metal or plastic that has magnetic material applied to it. Both sides of the disc are in use. Bits are kept in places known as tracks that run in concentric rings on magnetized surfaces. Tracks are typically divided into sectors for this purpose.

Hard discs are discs that are affixed indefinitely and cannot be taken out by one person.

3. Optical Disks: It is a write-once, read-many laser-based storage medium. It has a long lifespan and is reasonably priced. Occasional users can remove the optical disc from the computer.

Types of Optical Disks

CD – ROM

• It’s called compact disk. Only read from memory.
• By burning pits in the disc’s surface with a controlled laser beam, information is written there.
• The diameter of the disc is 5.25 inches.
• It has a highly reflecting surface, which is usually aluminium.
• A CD-ROM has a 600 MB storage capacity, with each sector holding 2048 bytes of data.
• 16000 tracks per inch is the track density.
• The new access time is about 80 milliseconds, and the data transfer rate is about 4800 KB/sec.

WORM-(WRITE ONCE READ MANY)

• A laser beam is used to write the data to the disc.
• A user can only write data once.
• They preserve information for a long time, but access is slow.
• The written information can be read as many times as needed.
• Data that has already been written cannot be changed.
• Rewriting new or updated data to another area of the disc is an option.
• Usual size – 5.25 inch or 3.5 inch diameter.
• The usual capacity of 5.25 inch disk is 650 MB,5.2GB etc.

DVDs

• “DVD” stands for “Digital Versatile/Video Disc,” and there are two different kinds of DVDs:
  • DVDR (writable)
  • DVDRW (Re-Writable)
• DVD-ROMS (Digital Versatile Discs): These discs are read-only memory (ROM) devices with a range of applications. They have significantly more storage capacity than CD-ROMs. It has a substantial polycarbonate plastic layer on top that acts as a base for the additional layers. It is an optical memory with read-write capabilities.
• DVD-R: A writable optical disc called a DVD-R can only be used once. A DVD can be recorded on it. It resembles WORM a lot. So The storage capacities of DVD-ROMs range from 4.7 to 17 GB. The 3.5-inch disk has a 1.3 GB capacity.

3. Cache Memory

This particular high-speed semiconductor memory can make the CPU run more quickly. It acts as a buffer between the CPU and the main memory. It is used to keep track of the information and software that the CPU uses most frequently.

Advantages of Cache Memory

• It can be accessed more quickly than the main memory.
• It is faster than the main memory.
• It stores data in temporary use.
• It saves the applications that can be executed quickly.

Disadvantages of Cache Memory

• The cache typically has a small capacity for data storage.
• It costs a lot because of the semiconductors that are used.