The firm that makes computers or laptops stores certain applications in ROM memory, which is located on the motherboard.
The instructions that are programmed in ROM are carried out by ROM. As you surely have seen, the company’s name and emblem are the first things you see when you turn on your computer.
In order for the brand emblem and brand name to be visible as soon as the computer is opened, the corporation that created the computer had it encoded in ROM. The information in ROM is permanently stored and cannot be deleted by any user.
ROM memory is a non-volatile memory, hence it never forgets anything. I trust you are familiar with computer ROM.
How Many Types of ROM Memory?
There are several different kinds of computer ROM, each of which I shall go through in-depth with you.
The four different forms of read-only memory are listed below.
Learn Basic Fundamental of RAM & ROM
1. Masked Read-Only Memory (MROM)
MROM is a kind of read-only memory that is manufactured utilizing a mask to program it.
Since it is non-volatile, its contents are retained even when the power is turned off. MROM is the best choice for usage in devices that need speedy execution, such as embedded systems, because it is quick and has a short access time.
One drawback of MROM is that after it has been programmed, its contents cannot be changed since it cannot be reprogrammed.
Another drawback is that because it needs more voltage than other kinds of ROM, it may perform worse when connected to a battery.
However, MROM-containing devices may run without external power since it does not require refreshing like other forms of RAM.
2. Programmable Read-Only Memory (PROM)
One of the several ROM kinds that may be programmed to permanently store data is PROM. It makes it perfect for storing data that doesn’t need to be altered frequently, like a computer’s BIOS.
One-time programmable (ROM) chips, or PROMs, can only be programmed once. They become sealed and unchangeable after that. It is also known as One Time Write and One Time Programmable (OTP) (OTW).
These chips have a maximum bit storage capacity of two million. A unique PROM chip called the Basic Input Output System, or BIOS, is found on the motherboard of personal computers.
3. Erasable and Programmable Read-Only Memory (EPROM)
One of the several ROM kinds that may be electrically erased and programmed is EPROM. A number of floating-gate transistors make up its construction. Data that must be updated often or in huge numbers is stored in EPROMs.
They are also used to hold computer applications that must be run. Before the software may run after editing, it must be reprogrammed into the machine’s main memory.
The most popular technology for this purpose is flash memory, which can be instantly read and written by any machine with a suitable controller chip.
These two ROM (Erasable Programmable Read-Only Memory) kinds should be the ones you utilize the most as there are several more.
4. EEPROM (Electrically Erasable and Programmable Read-Only Memory)
EEPROM is one of the several ROM kinds that may be electronically wiped and rewritten. Data that has to be modified regularly can be stored there. In comparison to other ROM types, EEPROM is slower and has fewer write cycles.
You cannot use them for CDs, DVDs, or Blu-ray discs since the contents cannot be erased by light.
Flash memory comes in two different flavors: NOR (Not OR) and NAND (Not AND). NAND chips offer greater storage density while being more costly and quicker than NOR chips.
5. Flash memory
Electrically Erasable Programmable Read-Only Memory, or flash memory, is a kind of EEPROM.
As opposed to conventional EEPROM, flash memory may be wiped and reprogrammed in blocks rather than one byte at a time. As a result, flash memory can write data more quickly than EEPROM.
Solid-state drives, digital cameras, and USB flash drives all employ flash memory (SSDs). The maximum number of erase cycles for flash memory varies depending on size, which is one drawback.
There are two varieties of ROM: NOR and NAND. The internal information storage methods of these memories determine how they differ from one another.
With all cells connected by pass transistors, NOR (which stands for not OR) memory uses transistors to store bits in rows that go from 0 up to 1 (the first row has 0’s and 1’s going down vertically). This allows you to access an entire row by applying a single high voltage signal across a single cell in any column.
Why You Need ROM in Computer
ROM is one of the numerous forms of memory that are present in computer systems such to this, along with other types of memory.
As vital as RAM memory is to a computer system, ROM memory is just as crucial. Both memories serve different purposes, but we will only discuss ROM memory and explain why our computer needs it.
The information on what to do and when has already been encoded into the ROM. As an illustration, when we open a PC, the ROM itself instructs the RAM to load the operating system, turning on the device.
Other sorts of equipment, such as washing machines and microwaves, include this form of ROM.
I’m hoping you get it.