This java applet simulates the Pep/7 machine as described in chapter 4. It is fully interactive and allows you to enter values into memory using the Edit Memory button. To change the values of any register, just enter the values into its box and hit enter the program will interpret your input for whatever the current display base is. Single step through the code by using the fetch->decode->execute button. At anytime you may hit the reset button which will reset the machine and all its registers. The current value in memory will be retained so you can run the same program multiple times.