What is RAM and ROM?

What are RAM and ROM?

RAM (Random-access memory) and ROM (Read-only memory), which are the main hardware of the computer; It stores data in different ways. Random-access memory (RAM) holds data via transistors, while read-only memory (ROM) holds data permanently on immutable or semi-swappable chips. In this article, I will discuss what RAM and ROM are, how they work, what they do and the differences between them.

What is RAM?

RAM (Random-access memory) is a computer memory device that temporarily stores binary code generated data and machine code on its transistors. RAM; It can also be expressed as primary memory, main memory, random-access memory.

Random-access memory can read and write data in almost the same amount regardless of their physical location. It is quite fast compared to hard disks because it works independent of its physical location.

Data held in RAM is not permanent. In other words, the data in the memory will be completely erased, except for some memories, since the current in the transistors will be cut in cases such as shutting down, restarting, or disconnecting the computer from electricity.

Apart from traditional RAMs, RAMs that permanently store data have also been developed. [6]

What is ROM?

ROM (Read-only memory) is a memory chip in which read-only data is stored. In ROM, where data cannot be written as in RAM, data is written to chips using binary code. [1] Since the data is pre-written on the chips, the information in the ROM continues to be stored in cases such as shutting down the computer, disconnecting the electricity.

Data originally written to the ROM chip cannot be removed afterwards. [7] Read-only memory is also useful for storing systems known as firmware where simple functions and program steps are processed. [4] An example of a read-only memory (ROM) is the BIOS chip, which contains the basic information the computer needs to start up.

All ROM chips, including EEPROM, EPROM, continue to store their data in the event of a power or power supply failure. The data written to the ROM chip cannot be tampered with by the users.

What is EPROM?

EPROM, erasable programmable read-only memory, is a chip that can permanently store data and that data can only be erased by strong ultraviolet light. EPROM is a variant of ROM. While programming data in EPROM is done electrically, strong ultraviolet light is needed for erasing.

What is EEPROM?

EEPROM, electronic erasable programmable read-only memory, is a type of chip frequently used in today's computers that permanently stores small amounts of data. Data writing and erasing is done electrically. The repetitive writing of data in EEPROMs depends on the durability of the insulator in the chip. In other words, as a result of damage to the thin insulating materials on the chip, writing or erasing will not be possible.

What is PROM?

PROM, programmable read-only memory, is a memory chip that can only be programmed once after it is produced. Once the data has been programmed, it is not possible to change or delete the data.
Like other types of ROM, data is permanent and cannot be changed. It is used to store low-level programs such as firmware or microcode. The PROM chip was widely used in the BIOS systems of previous computers. [9]

What are differences between RAM and ROM?

RAM (Random-access memory) ROM (Read-only memory)
Can store large data. Can store data in small sizes.
Data exchange is fast. Read, write, delete etc. transactions are performed quickly. Data read speed is many times lower than RAM. [8]
Operations such as read, write, delete can be done. Data is read-only. Data cannot be tampered with by users. Data is programmed during or after production.
Data is deleted in case of power supply failure. Data is stored permanently. After the power supply is interrupted, the data continues to be stored.
It is used on computers to prevent repeated reading of the read data and to open applications faster. System startup settings, BIOS settings, or memory where software instructions are programmed.
It costs too much. It costs less.

RAM and ROM, which are the basic parts of the computer, store data in different ways. Data is stored temporarily in RAM while data is stored permanently in ROM. Again, while large amounts of data can be stored in RAM, lower amounts of data can be stored in ROM. I have discussed such differences between RAM and ROM in detail in the table after explaining what RAM and ROM are.

In this article, I talked about what RAM and ROM are, what they do, and the differences between random-access memory and read-only memory. See you in future articles.


Ömer Faruk Coşkun - ÖFC'
Ömer Faruk COŞKUN

İstanbul Üniversitesi-Cerrahpaşa Bilgisayar Mühendisliği öğrencisiyim. Araştırmayı ve öğrenmeyi aynı zamanda öğrendiklerimi paylaşmayı seviyorum.