pythonRSC 1.2.0

An emulator for the RSC architecture written in Python.

pythonRSC ( Relatively Simple Computer in Python )

pythonRSC is an emulator for the RSC architecture written in Python.

With this program, you can generate bytecode from microcode files for Logisim or just emulate microcode files out right. Additionally, you can debug your program and see its every step or even generate a control flow graph of your emulated program.

Installing pythonRSC

To download the package, you can simply use pip.

pip install pythonRSC

Emulating your microcode using pythonRSC

After downloading the package, you should have access to a command called 'pythonRSC'. To use this command, you will need a microcode file to emulate. There are some test files provided.

pythonRSC run microcode.txt

This will parse the given microcode and output the state at the end of emulation.

Generating bytecode using pythonRSC

If you desire to use the in-built assembler to parse the microcode into logisim bytecode, there is a command for that. You will need to provide a microcode input file and it requires an output file to function.

pythonRSC assemble microcode.txt -o output.txt

Emulating and debugging your microcode (timelessly) using pythonRSC

If you want to debug your program, pythonRSC provides an easy-to-use debugger similar to GDB Debugger, but it is timeless! Timeless means you can go forwards and backwards in execution, so this will prevent you having to restart the emulator chasing an issue. To start the emulator with the debugger, use the following command.

pythonRSC debug microcode.txt

After executing, you will be met with a blinking >> awaiting your next command. The list of commands accepted by the debugger are listed below.

stepi [stepsize] This will 'step' forward once if stepsize is not provided, otherwise it will step as many times as provided in stepsize.

backi [stepsize] This will 'step' backwards once if stepsize is not provided, otherwise it will step as many times as provided in stepsize.

bp [addr|label] ... This will set a breakpoint at the given address(es) in hex or decimal or at given label(s). Breakpoints are enabled on initialization.

enable [addr|label] ... This will turn on a breakpoint if it was disabled, it can take a variadic amount of breakpoints to be enabled.

disable [addr|label] ... This will turn off a breakpoint, it can take a variadic amount of breakpoints to be disabled.

disas [start] [end] This will take a range of addresses and disassemble the instructions. Hexadecimal or decimal.

disas This variation of the disassemble command will try to identify if you are inside a label and disassemble that label for you.

print [type] [reg] This will print a register in your desired format (type). The types are /d (decimal) /t (binary) /x (hexadecimal).

run Resumes emulation unless a breakpoint is hit or HALT is met.

info This will print the current state of the emulator, in other words print all registers.

help This will just list the possible commands.

Generating a control flow graph for your microcode

If you wish to generate a control flow graph from your microcode, you simply pass a flag to the CLI.

pythonRSC run microcode.txt -cfg pdf or pythonRSC debug microcode.txt -cfg png

Graphviz is required to be downloaded and on your PATH for this to work properly.

The control flow graph will appear at the end of execution. The graph is rendered using Graphviz and the library pythonCFG.

An example graph: