Random-Access Stored-Program Machines, an Approach to Programming Languages

A new class of machine models as a framework for the rational discussion of programming languages is introduced. In particular, a basis is provided for endowing programming languages with semantics. The notion of Random-Access Stored-Program Machine (RASP) is intended to capture some of the most salient features of the central processing unit of a modern digital computer. An instruction of such a machine is understood as a mapping from states (of the machine) into states. Some classification of instructions is introduced. It is pointed out in several theorems that programs of finitely determined instructions are properly more powerful if address modification is permitted than when it is forbidden, thereby shedding some light on the role of address modification in digital computers. The relation between problem-oriented languages (POL) and machine languages (ML) is briefly considered.