PathSim is a simulator for the simple data path discussed in chapter 4 of

Computer Organization and Design, 5th ed.
David A. Patterson and John L. Hennessy
Morgan Kaufmann Publishers, 2013

The simulator is written in Java 8 (javafx) and runs through an executable jar file (PathSim.jar). The simulator presents a graphical depiction of the architecture shown in chapter 4 and allows its users to enter MIPS assembly code and step-wise execute through the assembled machine code while viewing the values placed on the data lines with each instruction

PathSim is no longer available from this website BUT can be obtained by contacting the author

Dalton R. Hunkins, Professor Retired
Computer Science Department
St. Bonaventure University