Even though he is no longer with us, I'll address what we think might be the question:
1) Using Ruby 0.48? Seriously? Why in the world would you ever, even if you supposedly have the source code. I don't even know what state Ruby was in at that version, or if it was really even usable, let alone stable.
2) You can really get the "source code" from a DLL. .NET managed assemblies are an exception to that, but the best you can hope for normally is some pointers with the return type, and argument types. There are a few debuggers/decompilers out there, none of which work in the way that you are hoping for. A few are WinDSM, IDA, and Olly Debug. By the very nature of your question, I can probably say that these programs will be nothing more than a confusing mess with which won't help you. They are definitely for advanced users, and are even hard to use for them.