Primary memory has limited computer storage capacitance and is volatile. Secondary retentivity overcomes this limitation by providing perpetual storehouse of data and in bulk quantity. Secondary memory is also termed external retentiveness and refers to the various storage media connected which a computer can put in data and programs. The Secondary storage media stool be fixed or removable. Stationary Storage media is an domestic storage medium like a baffling disk that is fixed inside the computer. A storage medium that is portable and can be taken outside the computer is termed removable storage media.
Difference 'tween Primary Memory and Secondary Computer memory:
| Primary Memory | Secondary Memory |
|---|---|
| Primary memory is directly accessed away the Centrical Processing Unit(C.P.U.). | Secondary memory is not accessed in real time past the Of import Processing Unit(Processor). Instead, data accessed from a secondary memory is first loaded into Random Access Memory(Read/write memor) and is and so sent to the Processing Unit of measurement. |
| Pound provides a much faster-accessing speed to information than secondary memory. By loading software system programs and needed files into primary memory(RAM), computers can procedure data much to a greater extent quick. | Lower-ranking Memory is slower in information accessing. Typically primary memory is six multiplication quicker than secondary memory. |
| Primary memory, i.e. Random Access Memory(RAM) is evaporable and gets wholly erased when a computer is fold. | Secondary memory provides a boast of being non-volatile, which means it can hold on to its information with or without electric power supply. |
Uses of Minor Media:
- Permanent Storage: Primary Memory (RAM) is vaporific, i.e. it loses all info when the electrical energy is turned off, so ready to secure the data permanently in the device, Auxiliary storage devices are needful.
- Portability: Storage mediums, like CDs, blink drives can constitute used to transfer of training the information from unitary device to some other.
Fixed and Removable Storage
Set Storage-
Read-only memory is an internal media twist that is utilized away a ADP system to store data, and usually, these are referred to as the Fixed harrow drives or Hard Drives.
Geosynchronous storage devices are literally not fixed, plainly, these throne be removed from the system for repairing work, maintenance purposes, and besides for an upgrade, etc. Merely in general, this can't be done without a proper toolkit to pioneer the computer system to allow for physical accession, and that needs to be done by an direct.
Technically, almost wholly of the data i.e. being processed on a computer organization is stored on extraordinary type of a integral fixed storage device.
Types of frozen computer storage:
- Internal flash memory (rare)
- SSD (solid-state disk) units
- Punishing disk drives (HDD)
Removable Storage-
Removable storage is an external media device that is used by a computer system to store data, and usually, these are referred to as the Eradicable Disks drives or the External Drives.
Removable storage is any type of storage device that can be removed/ejected from a ADPS spell the system is running. Examples of external devices include CDs, DVDs, and Blu-ray disk drives, likewise as diskettes and USB drives. Obliterable entrepot makes IT easier for a exploiter to transfer data from one computer system to another.
In repositing factors, the main benefit of removable disks is that they can provide the fast data transfer rates associated with cargo area networks (SANs)
Types of Removable Depot:
- Optical discs (CDs, DVDs, Blu-ray discs)
- Memory card game
- Floppy disks
- Magnetic tapes
- Harrow packs
- Theme storage (punched tapes, punched cards)
Secondary Storage Media
There are the following main types of storage media:
1. Magnetic storage medium media:
Magnetic media is black-coated with a magnetic layer that is magnetized in clockwise or levorotary directions. When the disk moves, the head interprets the data stored at a specific location in binary star 1s and 0s at reading.
Examples: catchy disks, floppy disks, and magnetic tapes.
- Floppy Disk: A floppy is a flexible disk with a magnetic coating on information technology. It is packaged inside a protective plastic envelope. These are one of the oldest types of portable storage devices that could computer memory up to 1.44 Bachelor of Medicine of data but now they are non used ascribable identical short retentiveness storage.
- Hard disk: A embarrassing disc consists of cardinal or more ringed disks called platters which are mounted on a informal spindle. Each skin-deep of a record is coated with magnetic material. Both surfaces of for each one disk are capable of storing information except the top and bottom disks where only the inner skin-deep is used. The information is canned on the aerofoil of the rotating disc past magnetic read/write heads. These heads are coupled to a mutual arm known as the get at arm.
Hard disk repulse components:
Most of the basic types of hard drives arrest a keep down of disk platters that are placed close to a spindle which is placed inside a sealed chamber. The chamber also includes read/drop a line heads and motors. Data is stored along each of these disks in the arrangement of concentric circles named tracks which are divided further into sectors. Though intrinsic Hard drives are not identical movable and are used internally in a computer system, external grueling disks can be used as a substitute for man-portable storage. Hard disks can store information leading to several terabytes.
2. Optical reposition media
In sense organ repositing, media entropy is stored and read using a laser beam. The data is stored as a spiral design of pits and ridges denoting binary 0 and positional notation 1.
Examples: CDs and DVDs
- CD: A Compact Winchester drive(CDD) is a device that a computer uses to read information that is encoded digitally on a CD(CD). A CD drive terminate be installed inside a computer's compartment, provided with an opening for easier disc tray access or it can be victimised past a peripheral twist socially connected to one of the ports provided in the computer system. A thickset disk or CD potty store approximately 650 to 700 megabytes of data. A data processor should have a Cardinal Force to study the CDs. There are iii types of CDs:
| Candela- Fixed storage | Compact disc recordable | CD-RW |
|---|---|---|
| It stands for CD – Read Only Memory | It stands for Compact Magnetic disc- Recordable. | It stands for Heavyset Disk-Rewritable. |
| Data is left-slanting on these disks at the time of manufacture. This data cannot Be changed, once is it written by the manufacturer, merely can only exist read. CD- ROMs are used for school tex, audio and video dispersion the likes of games, encyclopedias, and covering software. | Information can embody recorded on these disks only only once. Once the data is codified in a CD-R, IT cannot be erased/altered. | It can be read or written multiple times but a CD-RW drive needs to live installed on your computer before editing a Cadmium-RW. |
- DVD:
It stands for Extremity Versatile Disk or Digital Video Disk. It looks just like a Cardinal and uses similar technology as that of the CDs but allows tracks to be distributed closely enough to store data that is more than six times the Atomic number 48's capacity. It is a significant advancement in portable store engineering. A DVD holds 4.7 GB to 17 GB of data. - Blue Radiate Disk:
This is the latest optical memory media to store senior high-definition audio and television. It is similar to a Candela operating room DVD just can storage capable 27 GB of information on a undivided-layer disc and up to 54 GB of information on a dual-layer disk. While CDs or DVDs use a red laser beam, the blue-ray phonograph record uses a nonindulgent laser to register/write information along a disk.
3. Solid State Memories
Solid-express computer storage devices are based on electronic circuits with atomic number 102 squirming parts like the reels of tape, spinning discs, etc. Solid repositing devices use extra memories called flash computer memory to store data. A solid get (OR flash memory) is used mainly in digital cameras, pen drives, or USB flash drives.
Pen Drives:
Pen Drives Oregon Thumb drives operating theatre Brassy drives are the late emerged portable storage media. It is an EEPROM-founded flash memory that can be repeatedly erased and statute using electric automobile signals. This memory is accompanied by a USB connector which enables the indite drive to connect to the computer. They have a capacity smaller than a hard record but greater than a CD. Pendrive has the following advantages:
- Transfer Files:
A pen drive is plugged into a USB port of the system can be misused as a device to transplant files, documents, and photos to a Microcomputer and as wel vice versa. Similarly, selected files seat be transferred between a pen drive and any type of workstation. - Portability:
The lightweight nature and littler sizing of a pen drive go far possible to carry it from invest to target which makes data transportation an easier chore. - Relief Storage:
Most of the pen drives today come with the feature of having password encoding, great info related to family, medical records, and photos can be stored along them as a backup. - Raptus Information:
Professionals/Students can now easy transport medium-large data files and video/audio lectures on a pen drive and gain access to them from anywhere. Independent PC technicians can store function-affine public-service corporation tools, assorted programs, and files connected a high-velocity 64 United Kingdom pen drive and move from indefinite site to some other.
cds and dvds are examples of magnetic storage media
Source: https://www.geeksforgeeks.org/introduction-of-secondary-memory/
