BEAMOS, for Beam Addressed Metal Oxide Semiconductor, is a new technology for auxiliary memories based on an electron beam which reads and writes data on a simple unstructured MOS chip. Its performance features include large bit capacity (>

bits/module), rapid access time (<30 microseconds), high data transfer rates, nonvolatile storage and low cost in comparison with memories of comparable performance. The memory component is rugged, all electronic, and relatively insensitive to temperature and vibration, making it especially attractive for military applications. Its fast access time should provide considerable performance improvement in both commercial and military computer systems.