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title: ROM
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## Read Only Memory

Read-only Memory (ROM) is a self-descriptive type of memory that references the idea that a computer and its applications can only read data from it. This is in direct contrast to other memory types, where it is possible to read and write data and store it in memory. It is mainly used to store programs and data which generally do not need any modification throughout the life of the device.


### Examples of ROM 

#### BIOS ROM
In the early days of modern computers, one of the most common ROM chips used was the BIOS (Basic Input Output System) ROM.  The chip would hold specific instructions that a computer needed in order to start up and it was critical that the information could not be accidentally modified. Once the BIOS ROM chip was installed (generally soldered to the motherboard), it could not be modified. Fast forward to the 2000's and BIOS technology had improved to where a BIOS could now use EPROM (An erasable type of ROM) where the instructions could be updated in a controlled fashion by the manufacturer, but the operation of the chip would still have the same behavior in being read-only. The act of "updating the BIOS" for a computer is, in fact, updating the programming of the EPROM Bios.

#### CD-ROM
The CD-ROM is a type of compact disc storage object that requires the use of an optical laser to read the data off the disc. The devices used to read the data house the lasers and are called CD-ROM Drives. The disc itself is generally created in a factory and once made, is read-only. This is in contrast to the CD-R (compact disc recordable) medium which has the additional ability to hold new data.

#### ROM cartridge
ROM cartridges appear in the 1980's with the rise of personal computing. They are designed to be connected to a wide variety of devices, from calculators to home video game console systems. They are used to load software or enable specific hardware. Despite their quick load times and general robustness, they fell into disuse due to a smaller capacity and higher production costs than optical media.

![ROM](https://upload.wikimedia.org/wikipedia/commons/thumb/8/83/N64-Game-Cartridge.jpg/2560px-N64-Game-Cartridge.jpg)
*A Nintendo 64 "Game Pak" ROM cartridge*

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#### More Information:
<!-- Please add any articles you think might be helpful to read before writing the article -->
- [Read-only memory](https://en.wikipedia.org/wiki/Read-only_memory)
- [BIOS](https://en.wikipedia.org/wiki/BIOS)
- [CD-ROM](https://en.wikipedia.org/wiki/CD-ROM)
