The increasing need for large-scale computations has led to new interest in optical parallel computing. Digital parallel processing can be implemented using optical truth table look-up techniques. With optical-logic-based pattern recognition, a content-addressable memory can be constructed. The use of the EXCLUSIVE OR and NAND logic operations to achieve content addressability is discussed. This memory system can be used to perform digital truth table look-up processing. Operations such as addition and multiplication of 4-, 8-, 12-, and 16-bit words in parallel arrays are then directly possible. The number of reference patterns that must be stored is dramatically reduced by the use of the (binary-coded) residue number system and logical reduction tech-niques. An example 16-bit multiple-word-parallel (of order 1000) fixed-point multiplier is discussed.