The acronym ROM means Read Only Memory. The term is used to describe computer memory chips that have pre-set programs recorded on them. The chip stores information for the computer which is always available even when the computer is not running. Data stored in ROM or mask ROM is not normally changeable because it is used to distribute firmware that is not likely to need changing. Most computers come with Read Only memory to enable them to run checks on the hardware and facilitate loading of the computer’s operating system.
From inception of the integrated circuit, mask ROM was developed. In each mask ROM, chip all the data is actually fixed into the chip’s circuit so programming is done at production. To bring one’s read only memory up to date requires the physical removal and replacement of the memory chip but modern versions were developed to facilitate re-writing. Many of the early disadvantages of ROM were addressed with the advent of types of rewritable Reader Only Memory chips.
One such alternative is the Programmable Read Only Memory created in 1956 to permit the modification of the components to suit the designer, via electronic pulses. Others include the Erasable Programmable Read Only Memory and Electrically Erasable Programmable Read-only Memory invented in 1971 and 1983 respectively. Added features was the ability to return EPROM to its original state if needed, giving a clean slate for programming on each occasion and the advantage of programming the EEPROM chip without changing its structure or returning it to the manufacturer.
Later in the 1980s to 90’s flash memory which is a type of EEPROM offered an additional benefit of accommodating multiple rewriting without compromising the chip. With the use of these new types of ROM, the popularity and usage of mask ROM in its original state began to decline.
The rationale for Read only memory is based on the fact that all computers need some form of storage program that records and keeps all the details of changes and how it executes tasks. It was the form chosen to perform this task in almost every storage program computer. Before its advent in order to have programs run they had to be connected by hand to the machine.
ROM stores firmware for the main processor of most modern personal computers. It has become something of a standard as it relates to embedded systems. It has extended itself to use with not just personal computers but appliances, electronics and industrial robots. In 2008 most products with a processor were using Flash which adds the benefit of being able to connect to a pc for any firmware updates. Mask ROMs are therefore not typically used because of their inflexibility. This has undoubtedly given way to more adaptable forms being used and developed.