Abstract: Method and apparatus are provided for a general purpose photonic computer. A data signal is input through an encoder to encode such signal with an instruction. The encoded signal is transmitted by means of a laser beam to an input buffer where it interferes with a reference beam so as to form an interference pattern therein as a hollogram, IPH. A read beam is directed through the IPH and through a decoder which reads the instruction as having, e.g. an OP Code, data source and destination. The decoded instruction is forwarded on the read beam to ALU spin media which respond to the instruction by flipping spins between >2 energy levels, in one or more sequences of data patterns which are read or measured by one or more sensors. Such sensors can be one or more of RF, microwave or optical sensors, which sensors output radix >2 data signals for, e.g. storage, display or further processing as desired.