What is ROM: The full name of ROM is Read-Only Memory. This is only part of the primary memory of the computer. ROMs are used as a storage medium in computers and other electronic devices such as VCRs, game consoles, car radios. As its name suggests, data stored in ROM can only be read. Cannot write and modify anything in it.
ROM is a permanent memory or permanent memory. The information in which is stored permanently during creation. This type of memory is non-volatile, meaning it can retain the stored information even without a power supply.
What does Rom do?
ROM is also known as firmware. Firmware is data that is stored on the ROM of a computer or other hardware device. He provides instructions on how the device should work.
A ROM stores instructions that are necessary to start a computer. Typically, Basic Input-Output System (BIOS) data is stored in a ROM chip. The BIOS is used to initiate hardware during the booting process, and to provide services for operating systems and programs.
Where is the ROM located in the computer?
The main EEPROM and BIOS in the computer are on the computer motherboard.
Types of ROM
There are mainly 3 types of ROMs, which are;
- PROM (Programmable Read-Only Memory)
- EPROM (Erasable and Programmable Read-Only Memory)
- EEPROM (Electrically Erasable and Programmable Read-Only Memory)
1. PROM (Programmable Read-Only Memory)
- Data can be written only once on the PROM memory chip. Once the program is written, it lasts forever on the PROM.
- The PROM is blank when manufactured, while the ROM is programmed during the manufacturing process.
- To write data to a PROM chip, you need a special device called a PROM programmer or PROM burner.
- Inside the PROM chip, there are small fuses that are lit during programming. Hence this process is called “burning the PROM”.
2. EPROM (Erasable and Programmable ROM)
- EPROM is a special type of memory that retains its data until it is exposed to ultraviolet light. That is, once the program is written, the data from the EPROM can be erased and can also be programmed again.
- To write and erase data on it, we need a special tool known as PROM programmer.
- There is an excess of electrical charge inside it during programming, which can last for about 10 years. This charge is lost when exposed to UV light.
3. EEPROM (Electrically Erasable and Programmable ROM)
- Electrical charge is used to erase data from the EPROM.
- Its specialty is that you can re-Erase and program on the EEPROM without the dedicated equipment, without removing it from the hardware.
- To write the program again in EPROM, you had to delete everything. But there is no need to delete everything to edit in EEPROM.
- It can be erased and reprogrammed about ten thousand times. Both erasure and programming take about 4 to 10 milliseconds.
- Nowadays EEPROM chips are used in computers.
what did you learn today?
Basically, ROMs can only be read. To update the program in the ROM, you had to remove and replace the chip. ROM is used for boot firmware in almost every computer. It contains some kilobytes of code that tell the computer what to do when the computer starts, eg, running hardware diagnostics and loading the operating system into RAM.
Hope you have liked the information given about ROM. If you have any questions related to this, then you can ask us in the comment below.