DATA STORAGE DEVICE

In a non-volatile electric memory system a card-like memory unit (10) and a read/write unit (11) are provided as physically separate units. The memory unit (10) is based on a memory material (4) that can be set to at least two distinct physical states by applying an electric field across the memory material. The read/write unit (10) comprises contact means (9) provided in a determined geometrical pattern enabling a definition of memory cells in memory unit (10) in an initial write operation, the memory cells being located in a geometrical pattern corresponding to that of the contact means (9). Establishing a physical contact between the memory unit (10) and the read/write unit (11) closes an electrical circuit over an addressed memory cell such that read, write or erase operations can be effected. The memory material (4) of the memory unit (10) can be a ferroelectric or electret material that can be polarized into two discernible polarization states, or it can be a material with a resistive impedance characteristic such that a memory cell of the material can be set to a specific stable resistance value by the application of an electric field.