how to programme rom chip?

how to programme rom chip?

Computer designers use EPROM and EEPROM devices for their prototypes. They use a special programmer to put their code into the devices. For low volume equipment, they might install and ship these reprogrammable devices into the enclosed space. They can also install PROGRAM ONCE devices for their product. Very high volume equipment will bring back a "Mask programmed" device, wish is manufactured next to the code into it.



Nearly every gasoline station in America have a Veeder-Root Tank gauge for managing gasoline inventory and reservoir leak detection. These devices use PROGRAM ONCE devices. Since the program is updated from time to time, they program these devices as a part of the pack of their manufacturing process. (Veeder-Root gauge and counters are found world-wide).
A true ROM is only programmable at time of making. Proms, eproms, and eeproms are a different story, but the answer depends on the nature of the device and where on earth it is installed.