Read-Only Memory (ROM)
The Read-Only Memory (ROM) is that part of the main memory that holds manufacturers’ instructions, which assists the Central Processor in performing special operations. These operations include telling the CPU what to do when the power is turned on, checking to see that the cables to the printer and the monitor are well connected, interpreting the meaning of each key on the keyboard.
Unlike the RAM, the instructions on the ROM do not disappear when the power is turned off. Information on the ROM can only be read. A good example of the ROM program is MS-DOS. ROM has the capacity to retain data and programs forever even during a power failure. ROM stores BIOs. It is smaller than RAM. Its content and information do not change.
Forms of ROM:
The various forms of ROM include:
1. PROM: Programmable Read-Only Memory (This version cannot be changed)
2. EPROM: Erasable Programmable Read-Only Memory (This version can be erased)
3. EEPROM: Electronically Erasable Programmable Read-Only Memory (This version can be erased by the application of current over time.