A read-only memory serves to store information

Someone think that this is very simple information, does it really need additional explanations? But there are people who ask the question "Does permanent storage work for what?", And this is not uncommon, so I would like to make some clarification regarding this topic.

What is a read-only memory?

A read-only memory serves to store data presented in an electronic version. There is another, more understandable to the average user formulation. A read-only memory serves to store programs that are used on electronic devices. Often it is made in the form of a rectangle, inside which there is a necessary hardware, which can provide storage of a limited amount of data under conditions when a constant electric voltage is not applied. In other words, the ROMs have an energetically independent memory, in which the necessary data is stored. If a person reads these words, then we can conclude that he already uses ROM, because he uses the appropriate device. If there is a desire to see the device first hand, then this can be done. How - depends on the device from which this article is read. If from a computer, it is necessary to remove the protective panel from the system unit and look at the front of the computer. There you can see a fairly small device measuring 20 * 10 * 4 centimeters or so (attention, now the conversation is about the computer's system unit, not about the laptop, do not mix it up). ROM looks like a piece of black plastic, bounded on the sides by iron plates.

So, you can say that a permanent storage device is used to store answers to all possible questions, because it is there that stores all the information that the user stores on his computer. But more information carriers will be considered further.

What are they like?

By the peculiarities of their use, we can distinguish two types of ROM:

• Portable. These include those permanent storage devices that are convenient to use when carrying from one computer or electrical device to another. This includes electronic memory books, flash drives and many other similar devices.
• Stationary. These devices are designed to be installed once and will be used for years. The ROM that is installed in the computer belongs to this species.

What is the difference between permanent storage devices?

Until recently, the main and most significant difference between them was the amount of information that can be written down. So, the main carriers were magnetic tapes and their derivatives - floppy disks, which had memory hundreds and thousands of times less than hard disks of computers. But there was a time, and now portable ROMs by memory size are not inferior to fixed ones, sometimes being modified for transferring hard disks of the computer. But even now there is a tangible difference:

• The size. As a rule, portable storage devices are still designed for a smaller amount of memory, so it is quite natural, they are smaller in size.
• Different types of connection to the computer itself, as well as the connection points: external and internal (outside the system unit and inside it).
• Speed of interaction. This is probably noticed by many readers. If you transfer files between folders on the computer itself in seconds, you will need minutes to transfer from the external device to the computer's memory.

Portable storage devices

To portable memory devices should be attributed such electronics:

• Electronic memory books. This permanent storage device serves to store huge amounts of data. So, these books correspond to the usual books of paper in size, but the amount of data that can be placed on them is impressive: this is up to 10 terabytes (such copies are available on sale at the time of writing the article).
• Disks based on laser technology (CD, DVD, etc.). Probably, many can find small collections of such carriers, on which there were games or films, and some even now, in the era of the Internet and free access to information, buy them for the home collection.
• Devices on the magnetic tape (floppy, now almost not used).
• Electronic reusable data carriers created with the use of technology "flash" (in the people they are known as flash drives). A small permanent storage device serves to store data up to several units or tens of gigabytes.

Stationary storage devices

These include:

• Hard disks that are installed in computers.
• Entire information systems of information accumulation, which can be seen in huge data centers.

Tips for choosing a ROM

And now, knowing in general and in general what permanent memory devices are intended for, it is not superfluous to find out which device to choose. But in order to avoid unpleasant disappointment, you first need to understand the system of data counting. The matter is that such devices work on a binary system, for which the number 1024 is important. So it turned out that 1 gigabyte has 1024 megabytes, 1 megabyte has 1024 kilobytes, etc. (this is a topic for a separate article). And manufacturers of carriers sometimes arrive dishonestly and take as a basis number 1000, rounding off value. You can buy a flash drive for 16,000 megabytes and you will be told that this is 16 gigabytes, but in reality there will be only 14.9 GB. And now to the advice:

• When buying, always check to see if the specified denomination on the drive meets the real state of affairs. Ask the seller to check on the computer installed in the store. In stores that appreciate customers, such a procedure is stipulated by the rules, so you do not have to worry and ask boldly.
• Examine the permanent storage device for external damage. The performance check from item # 1 here will also be useful.
• Check the quality of the nests. If damage is visible, select another product.
• And always remember about the rights of the buyer in the case of buying a substandard product.

And finally, let's repeat: the permanent storage device serves to store what? Data submitted in electronic form. We hope that after reading this article, any reader will be able to answer this question without any hitch.