It has been shown that reversible information storage in crystals can be achieved using the inhibition of cathodoluminescence by defects produced by electron irradiation. Since an electron beam of constant energy is used to access the store and to execute the binary operations of write, erase, and read, the addressing problems are minimized. The writing and erasing times are on the order of a few microseconds, and the reading time can be a few hundred nanoseconds.