Sim3 simulates a computer [Simpletron 3] executing a program written in SML, Simpletron Machine Language. An overview of the virtual computer is presented including details of the SML language, sample programs, and instructions on how to operate the "computer".
SML is an assembly language that provides for the reading, writing, and manipulation of integer data with the five operations: addition, subtraction, multiplication, division, and exponentiation. The user can enter a program, then watch the computer assemble and execute each statement.
During execution certain fatal errors are detected: attempt to divide by zero, accumulator overflow, invalid operation codes. These errors will produce an error message.
Logic errors will produce erroneous results. Careless user errors will cause the program to crash. The user must be careful to select and press the correct buttons. A buzzer will notify the user that data input is required so turn on the sound!
Both program and data reside in memory; it's the responsibility of the programmer to prevent overlap. Simpletron 3 has a RAM of 100 addresses from 00 to 99 and stores integer data in the range -9999 to +9999. The memory can be displayed at any time.