once. It is much like a CD-R drive that burns the data into the CD. Some companies use special machinery to write Proms for special purposes. 2.Erasable Programmable ROM (EPROM). This is just like PROM, except that you can erase the ROM by shining a special ultra-violet light into a sensor atop the ROM chip for a certain amount of time. Doing this wipes the data out, allowing it to be rewritten.3. Electrically Erasable Programmable ROM (EEPROM). Also called flash BIOS. This ROM can be rewritten through the use of a special software program. Flash BIOS operates this way, allowing users to upgrade their BIOS.ROM is slower than RAM, which is why some try to shadow it to increase speed.The term Static Memory or SRAM is a type of RAM and is one of the fastest, this is because it does not use the capacitive method. It uses instead different cells which represents a single bit and the value is held by a more complex set of transistors that are configured as a bistable that is commonly called a flip-flop. This type of memory will maintain itself until it is either altered by a new value or the power is switched off.The Static Memory also holds information as long as power flows through the circuit it does not need to be constantly refreshed though.The term Dynamic RAM or DRAM is a type of RAM it is not as fast as SRAM but it is smaller in size. It is mainly used for the computers main memory, but it is also volatile. It stores the data through a capacitor that holds the transistor in its switched state but the capacitor loses power quickly and has to be recharged on a regular basis which is roughly every two milliseconds. The term Memory Addressing means that it is able to store instructions in the memory at a location so it is then able to retrieve it again. It is a unique location and the contents may be part of an application program or system program, or may be data. This is important, as the machine must be able to distinguish one-program...
