A non-volatile dynamic memory cell in which the non-volatile element has two different areas for electron injection, such that direct overwriting of previously stored non-volatile data is permitted without an intervening erase cycle. The non-volatile storage element is a floating gate electrode (16) which has dual contro gates (24, 26) disposed thereon. Each control gate (24, 261 includes a layer (20A, 20B) of dual electron injector structure (DEIS) material and a polysilicon layer. When writing a "0" from the volatile storage capacitor (20,14A, 26) to the floating gate (16), one of the control gates (24, 26) removes charge from the floating gate (16). To write a "1", the other control gate injects charge into the floating gate (16). The above charge transfer does not take place if the previously stored logic gate and the logic state to be written in are identical.