COMPUTER STORAGE DEVICES.

9 min readOct 16, 2021

Storage is the action or method of storing something for future use. In the computer, storage is the process for retention of retrievable data on a computer through which digital data is saved within a data storage device.

We use storage devices to store the data and that can hold the data for permanently or temporary. They can be external or internal in computer. when we have less space memory, need to store, or move data we can use storage devices.

There are four types of storage.

· Primary storage — RAM, ROM, Cache

· Secondary storage — Hard disk

· Tertiary storage — Magnetic tape, Optical disk

· Off-line storage — Memory card, Flash drive, Floppy disk, Zip drive

Also, there are type of computer storage devices.

· Magnetic storage device. — Floppy disk, Magnetic tape, Hard disk, Zip drive

· Optical storage devices. -CD, DVD, BD

· Flash memory devices. — Flash drive, Memory card

· Online cloud storage

Primary storage

It also known as the main memory. But it also called internal memory, primary storage.

It holds data, program, instructions (transferred from secondary memory) that are currently using in CPU. Main memory is directly or indirectly connected to the central processing unit via a memory bus. Smaller than secondary memory but fast and the CPU continuously reads instructions stored there and executes them as required. It can be accessed by applications or other hardware systems in frequently. (b.ram)

There are three types of main memory.

· ROM (Read Only Memory)

· RAM (Random Access Memory)

· Cache

RAM

RAM also called Random Access Memory. Shortly called as a RAM. It is a volatile memory.

If computer switch off RAM will lose the memory which, are user currently used. Then why do we need RAM, it is very fast and stores data and program code needed by the CPU. And RAM is the simplest and most cost-effective way to get more speed from the computer. Data in RAM can modify.

EX: the music that you’re listening now, instructions which are needed for that process are store in RAM.

There are two types of RAM,

SRAM — (Static Random- Access Memory)

DRAM _ (Dynamic Random-Access Memory)

Differences between SRAM &DRAM

ROM

ROM, also known as Read Only Memory. As it names implies this memory can only read. Stores the instructions; firmware-updates (basic code to get the computer start) which are needed to be booting (turn on) the computer. ROM chips on hardware devices (like a BIOS chip), and they contain instructions the computer can use in performing some of the most basic operations required to operate hardware devices. In typically computer ROM is store in motherboard. Data in ROM can’t easily or quickly modify. Non — volatile memory. Unlike RAM, ROM can keep the data after the computer is shutdown intact. There are 3 categories of ROM,

PROM — (programmable read only memory)

EPROM — (erasable programmable read only memory)

EEPROM — (electronic erasable read only memory.

CACHE

Except the speed of cache memory, it is similar as RAM. Then why we need cache memory? Transferring data between CPU and RAM, CPU consumes more time. Because RAM speed is slower than CPU. As a solution for that, cache memory includes into the CPU. Cache memory very smaller and very fast. It holds the data which are CPU frequently used. When CPU need the data, cache memory can transfer the data immediately.

There 3 types in cache memory. L1, L2, L3. Most computers today come with L3 cache and L2 cache, while older computers included only L1 cache. Among the L1, L2, L3 have different speed.

. L1 — holds recently run instructions.

. L2 — holds upcoming instructions.

.L3 — holds many of the possible instructions

Secondary storage.

Data in secondary storage keep permanently. It is not directly accessible by the CPU. can consider as an external storage.

Example: Hard disk

Tertiary storage.

Level below secondary storage. Removeable. Can store large amount of data.

Ex: Magnetic tape

Optical disk

Offline storage

As the name implies, offline storage devices are not built-in computer. offline devices must be connected to the computer physical device when in use. Easy to use and easy to edit data. Non-volatile. Data cannot be replaced after once delete.

Ex: Floppy disk

Flash drive

Zip drive

Memory card

Magnetic storage devices

Data store as magnetic form. Capable to store large amount of data. Can re-write the data.

Ex: Hard disk

Magnetic tape

Floppy disk

Zip drive

Hard disk

Hard disk also called as hard drive, hard disk drive. Hard disk is a most important component in the computer, because without hard disk couldn’t operate the computer at all. No file saves, no download, or no play music. Non-volatile. It means hard disk can keep data permanently. Provide large storage capacity. IBM unleashed the world’s first computer hard drive in 1956. There are few components consist into the hard disk.

· platter — storing data

(one or more platters include. platters are made by aluminum, glass, ceramic. for substrate material with a thin magnetic surface, or media layer, to store data)

· read/write arm — reading and writing data

· spindle — spinning platters

· actuator — control the action and movement of the read/write arm and a logic board.

Formatted:

Before magnetic disk use it must be formatted (how data store). Hard driver create circular tracks around the surface and it divide small part called as sector. These sectors grouped by the computer operating system (OS) .it called cluster. When read file easy to track the locations using clusters.

There are few factors influence for hard disk performance.

RPM speed — Hard disk speed is the speed at which content can be read and written on a hard disk. platters spin rate measured by RPM.RPM higher, speed of hard disk faster. A hard disk unit comes with a set rotation speed varying from 4500 to 7200 rpm.

Latency — spend time for read desire data from spinning platter.

Spindle motor power and speed — speed of spindle motor can influence for hard driver read and write data from magnetic platter.

There are two types of hard disk,

Magnetic Tape

One of device that example for a magnetic storage device. Usually only one side stored the data. Data is store on plastic ribbon which is coated by magnetic oxide. Magnetic tape not very expensive but when read the data in magnetic tape can’t directly go to the data which one needs. Magnetic tape use serial access method for read the data . Nowadays capacity of magnetic tape around 580 TB.

Advantages & Disadvantages.

Floppy disk

Magnetic storage medium. Content with thin, flexible disk sealed in square plastic cover. in early expensive. capable to store 1.44 MB.

Zip diskette

First Zip driver introduced by company omega in 1994. In early of introduction became very popular. Can hold 100MB — 250MB data. Can store data more than 3 1/2inch floppy disk.

Optical storage devices.

When read the data need laser light. Data store as a pattern image. Portable. Capable read, write and re-write. There are 3 types,

Type of optical disk.

Flash memory devices.

Flash memory device is portable and non-volatile memory. Easy to use. It is a kind of EEPROM memory. That mean it can erase and write data using electronic device. Data store as a Solid -state memory medium.

Ex: Flash drive

Memory card

USB Flash driver

USB flash driver, also called memory stick or pen drive. Portable and very easy to use. Similar as portable hard drive. User can open, save, delete the files. Plug and play (device only needs to be connected to the computer). When connect pen drive into the USB port, the computer operating system (OS) recognizes the device as a removable drive and assigns it a drive letter. Lightweight. Can be used in place of a compact disc. Mostly used for storage, data backup, transfer the file among the devices. Pen drivers have different sizes 2GB, 4GB, and up to 256GB. This type of storage media is called solid state memory and differs from optical and magnetic drives.

Memory card

Memory card also known as flash card. phone, digital camera, MP3 player, such as portable, small, and electronic consumer devices commonly use memory card. There are three types of memory card.

SD (Secure Digital)

microSD

CF (CompactFlash)

: Flash memory and optical discs are commonly popular storage devices.

Online Cloud storage devices.

As it names implies data in cloud.it means it handle by third party. It’s not like physical devices such as USB flash drivers, hard disk, optical disk. Anyone can use online cloud storage. but when it uses that must need steady data connection.

More people were using remote technology, it may reason to lead to a rapid increase in cloud storage. Cloud storage was flexible and scalable. There are some examples for online cloud storage.

References

( 2021, October 1 ). Retrieved from https://en.wikipedia.org/wiki/Computer_data_storage#:~:text=Optical%20discs%20and%20flash%20memory,Zip%20disks%2C%20or%20punched%20cards.

b.ram. (n.d.). computer fundemental. architecture and organization. New age international (p) limited.

Chakrabarty, T. (2018, August 23). Online class Notes. Retrieved from https://onlineclassnotes.com/basic-differences-between-optical-and-magnetic-storage-devices/

computer Hope. (2019, april 2). Retrieved from https://www.computerhope.com/jargon/r/rom.htm

ComputerHope. (2020, November 30). ComputerHope. Retrieved from https://www.computerhope.com/jargon/c/compactd.htm

FLOYD, L. (2020, October 19). zoho. Retrieved from https://www.zoho.com/au/tech-talk/why-is-the-cloud-so-popular.html

Gregersen, E. (n.d.). Britannica. Retrieved from https://www.britannica.com/technology/hard-disk

hope, c. (2017, April 26). Retrieved from https://www.computerhope.com/jargon/o/offlstor.htm

introduction to computers . (n.d.). In p. norton, data storage. tata McGraw.Hill publishing company limitted.

kamau, P. (2021, june 17). turbofuture. Retrieved from https://turbofuture.com/computers/Types-of-Computer-Hard-Disk-Drives

Lelii, S. (2017, june). TechTarget. Retrieved from https://searchstorage.techtarget.com/definition/USB-drive

MKS075. (2020, September 4). GeeksforGeeks. Retrieved from https://www.geeksforgeeks.org/difference-between-blu-ray-and-dvd/

Papadopoulos, L. (2020, December 20). INTERESTING ENGINEERING. Retrieved from https://interestingengineering.com/new-magnetic-tape-delivers-a-record-580tb-storage-capacity

Parahar, M. (2019, November 26). tutorialspoint. Retrieved from https://www.tutorialspoint.com/difference-between-cd-and-dvd

prince, s. (2020, May 1). LifeWire. Retrieved from https://www.lifewire.com/dvd-formats-data-limits-1130690

rachnasoundatti3099. (2020, august 5). GeeksforGeeks. Retrieved from https://www.geeksforgeeks.org/difference-between-sram-and-dram/

rajkumarupadhyay515. (2020, April 28). geeksforgeeks. Retrieved from https://www.geeksforgeeks.org/magnetic-tape-memory/

Sanne. (2021, march 16). cool blue. Retrieved from https://www.coolblue.be/en/advice/types-of-memory-cards.html

Serafi, A. (2020, January 10). ASKINGLOT. Retrieved from https://askinglot.com/what-are-tertiary-storage-devices

Shamil, P. R. (2021, january 8). T4Tutorials. Retrieved from https://t4tutorials.com/hard-disk-components-characteristics-performance-and-hard-disk-controllers/

Software Testing Help. (2021, October 7). Retrieved from https://www.softwaretestinghelp.com/cloud-storage-providers/

study.com. (2021, august 31). Retrieved from https://study.com/academy/lesson/magnetic-storage-definition-devices-examples.html

techopedia. (2017, January 26). Retrieved from https://www.techopedia.com/definition/2600/blu-ray-disk-bd

techopedia. (2018, March 7). Retrieved from https://www.techopedia.com/definition/24481/flash-memory

Tikkanen, A. (n.d.). Britannica. Retrieved from https://www.britannica.com/technology/magnetic-tape

WIRED. (2014 , 03 01). Retrieved from https://www.wired.com/2014/01/tech-time-warp-ibm-ramac/

writer, S. (2020, March 24). Retrieved from https://www.reference.com/business-finance/advantages-disadvantages-magnetic-tape-768ce0fe084eb946

Zandbergen, P. (2021, September 13). Study.com. Retrieved from https://study.com/academy/lesson/what-is-a-zip-drive-definition-lesson-quiz.html

Zandbergen, P. (2021, September 9). Study.com. Retrieved from https://study.com/academy/lesson/what-is-floppy-disk-definition-advantages-disadvantages.html