photodigital memory

A memory consisting of photographic film on which data is written by laser beam or focused light beam in the form of exposed dots (1bits) and unexposed areas of dot size (obits). When the film is developed, it becomes a permanent readonly memory.; 利用激光束或聚焦光束将数据写入照象胶片而形成的存储单元。 凡曝过光的点作为二进制1,未曝光区域的点作为二进制0。在胶片显影后变成永久性只读 存储器。