By Ziyi Shao
Most computers contain a small amount of ROM that stores critical data that allows the computers to boot itself. ROM is computer memory on which data has been prerecorded and can only be read. There are five basic ROM types. Each type has unique characteristics, but they all have two things in common; data in these chips is nonvolatile and is either unchangeable or requires a special treatment to change. ROM was first invented in 1890. The earliest versions were made by directly writing binary data on a silicon plate using a type of stencil. This was a very primitive method and consequentially created many problems.
An upgrade from ROM was developed in 1959 called PROM (programmable read only memory). These memory chips are manufactured as a blank memory chip. PROMs are memory chips made of thousands of fuses that can be "burnt" using a "ROM programmer", which is applied at a high voltage. The fuses represented 0 and the parts left alone represented 1. There are many problems with PROMs. They could only be programmed once, are more fragile than ROMs.
EPROM is short for Erasable Programmable Read Only Memory; it solved the biggest problem with PROM which was the inability to reprogram. These memory chips have a glass panel that lets ultra-violent rays through. The binary data is erased when the memory chip receives ultra-violent rays with a certain wavelength that causes all of the memory bits return to 1.
The next version is called EEPROM which is short for Electrically Erasable Read Only Memory. It is like EPROMs but can be erased by a simple electrical current. They do not have to be erased and it is possible to only change a specific portion of it, or rewrite it directly. Flash memory is a variant of EEPROM. Unlike the classic EEPROMS that use 2 to 3 transmitters for each bit to be memorized, the Flash Memory uses only one transistor meaning it is a lot faster.
In conclusion, ROM was a huge advance in technology because it allows computer to start up as well as many other things. The development of ROM was dramatic and went from silicon plates with binary data carvings to flash memory. Now, we can do so many things with the latest versions of ROM and it is still improving.
