What is ROM memory?
While not usually as much attention is paid as with RAM and processor, ROM memory is also one of the most important components that make up a computer, since it is a more than fundamental link in the boot chain of a PC. Your mission is memorize all the necessary parameters so that every time we turn on the PC, remember how and in what order you need to do it, among other activities.
This electronic component has been present on motherboards since the beginning of computers, but we can also find it on mobile phones, tablets and many other devices that need a startup routine. If you want to know everything about this electronic component of computers and phones, don't hesitate to read on this post about ROM memories, where you will find clear and concise information on how it works, the different types of ROM memory that exist and many other very interesting information on the subject.
- What is ROM memory?
- What does ROM mean?
- ROM function
- Types of ROM memory
- Differences between ROM, EPROM and Flash EEPROM
- Difference between RAM and ROM
What is ROM memory?
ROM memory is an electronic component that can be found in computers and portable devices such as cell phones, cell phones and tablets, but we can also find it in Smart TVs, audio players and many other types of devices. the function of storing the data and instructions necessary to start the device, that is to start, normally.
In particular ROM memories can be written, but through special procedures like the ones we use when we update the computer's BIOS to improve its functions, a task that can be easily done these days and is even encouraged by most motherboard manufacturers.
What does ROM mean?
The term ROM is short for "Read only memory" which in our language means "Read only memory", and which, as its name indicates, stores information and instructions that can only be read, that is to say that in this type of memories no new data can be written, unlike RAM memories, as we can see later in this same post.
As we mentioned, ROM memory is a chip or integrated circuit that can store information inside, which cannot be altered, at least accidentally. Likewise the ROM memory can keep the data recorded in its circuits even when it is not powered, that is, when there is no power source to keep them there, unlike RAM memories, which in the absence of power to power them immediately lose the contents of their cells.
This makes ROM memory extremely efficient for booting an electronic device such as a computer, a smartphone or any other device that always requires to start in the same way, since the data and startup routines it stores in it will always be stored there, and in the same state in which they were stored.
Basically, the role played by ROM memories inside devices, specifically in the case of computers, it is a question of keeping all the startup codes and instructions necessary for the PC to start up every day and every time we turn it on in the same way.
among many PC startup process management activity which contains the ROM memory, One of them is extremely important: starting the PC operating system, without which, as we know, a computer today would be of little use. But in addition, the ROM memory takes care of performing all the initial analysis and checks of the system, as well as the multiple check routines of all the input and output devices.
Types of ROM memory
Basically, the memories used to store the startup routines of a device are divided into two types: those that are programmable and those that are not. the second type, composed of ROM memories and PROM memories, have ceased to be used in the field of information technology, since they have been replaced by overwritable memories, i.e. memories of the first type, among which are EPROM and EEPROM memory.
Below these lines we will know the Basic differences between ROM, PROM, EPROM and EEPROM memories.
ROM (read-only memory)
ROM (read-only memory) or read-only memory It was the first type of read-only memory that was produced, and to store information inside it a procedure was used that involved the use of a silicone plate and a mask, for which every possibility of being able to do so manually it was impossible. . ROM type memories have been replaced by EPROM and EEPROM type memories, which could be overwritten.
PROM (programmable read-only memory)
PROM memories (Programmable Read Only Memory) or Programmable Read Only Memory Readingis a military development of the mid-1950s. The most surprising thing about this type of memory is that the procedure for recording the data on the chip was performed by applying a voltage overload, between 12 and 20 Volts, to the diodes in the circuit. integrated, through a device known as ROM programmer.
The chips came from the factory with all diodes intact, all corresponding to the value "1" - When they were overloaded, they went to have a value of "0". As we can see, it wasn't even possible to do this manually. This type of PROM memory has been used in Sinclair ZX Spectrum computers, among others.
It is specified that the term "burn", used for this type of activity, it derives from the voltage combustion of the diodes of these memories.
EPROM (Erasable Programmable Read Only Memory)
EPROM type memories, (Erasable Programmable Read Only Memory) or Programmable and Erasable Read Only Memory, Basically they are PROM type memories but unlike these they offer the possibility of being able to delete the content stored in them.
EPROM memories are programmed by emitting ultraviolet light rays, which enter the circuit through a window in the integrated circuit package.
EEPROM (electrically erasable programmable read-only memory)
EEPROM memories (electrically erasable programmable read-only memory) or electrically erasable programmable read-only memory, they are erasable, just like EPROM memories, except that in this case the procedure for erasing and rewriting the memory is much simpler, as an electric current is used.
EEPROM memories offer a variant called Flash EEPROM, which uses fewer components and is able to read the registers it contains one by one, which affects the performance of the chip.
Differences between ROM, EPROM and Flash EEPROM
Although the term ROM is still used today, the truth is that things have changed a bit, since the "read only" contained in the acronym is no longer true, because memories of this kind today can be written several times and quite simply. An example of this is when we update the bios.
Let's remember it The term ROM comes from an era when ROM memories left the factory already registered with data and instructions. that they should have had based on the device on which they would be installed and there was no possibility to change the content.
Nowadays, the term ROM is still used by simple convention, since the new memories of this type, which in recent years have replaced the old ROMs, and thanks to which practically we can't find a device on the market that still has an old ROM installed, you can write them
These types of ROMs are called EPROM and Flash EEPROM. and although we must have knowledge, experience and some specialized software tools to modify its content, the truth is that the content modification routine of a modern ROM is quite simple.
But the most important thing to remember is that Unlike ROMs, EPROM and Flash EEPROM can be written, that is, to record new data, many times. This fact allows, for example, to update the BIOS and take advantage of its new features and with our means and without significant problems in the procedure.
Difference between RAM and ROM
In a computer, two types of memory coexist, RAM and ROM. each pursuing a very specific purpose. RAM, or random access memory, performs the function of storing in it the data most used by the operating system and user applications, a much faster method than having to search directly on your hard drive.
Also, the RAM memory can be overwritten several times, but its content, that is, the data stored in it, is temporary. which means that in the event of a power failure they will be lost.
On the contrary, the content stored in the ROM memory is not erased in the event of a power failure, which, as mentioned, makes it the ideal substrate for the startup functions of a computer, and since it cannot be written, at least by simple means and by the hand of any user, guarantees that the device will always start the same way.
If you want to know other articles similar to What is ROM memory? you can visit the category Internet.