1. A stack oriented microprocessor computer system comprising a main memory (10) for storing programs comprising a plurality of reverse polish (i.e., postfix) stack oriented instruction tokens, a stack memory (33), and an instruction execution unit (14) characterized by an operand stack storage mechanism (20,21,22) for storing tokens received from said main memory and referring to operands, an operator storage mechanism (24) for storing tokens received from said main memory and referring to operators, at least one lookahead storage mechanism (23) for storing either an instruction token referring to an operator received from said main memory or an instruction token referring to an operand following an instruction token referring to an operator received from said main memory, and means (18 and 31) responsive to said storage mechanisms for optimizing storage accesses by dynamically combining a plurality of said operand tokens and said operator tokens for simultaneous execution by said instruction execution unit.