The educational range of visual simulations of the Little Man Computer architecture paradigm

The Little Man Computer (LMC) paradigm was developed at MIT during the 1960s where it was taught to all undergraduate computer science students. LMC consists of a cartoon character inside of a walled room containing mailboxes, a calculator, a counter with an external reset switch, and input/output baskets. Although this analogy between the internal operations of a hypothetical computer and a real computer is not perfect, LMC has proved itself enduring, intuitive, powerful, and an extensible teaching paradigm. In this paper we present a range of visual LMC simulators from K-12 to post-graduate educational levels. In particular we highlight four simulators in detail: (1) a K-12 interactive CD-ROM LMC tutorial; (2) an undergraduate web-based LMC Shock-Wave animated simulator; (3) an undergraduate web-based LMC Java simulator; and (4) an extensible undergraduate/graduate LMC/Postroom computer. Together these simulators provide a powerful selection of tools for illustrating the concepts of computer systems architecture.