Many years ago, when I programmed in BASIC and Paradox, I had access to tools that would generate execution diagrams from existing source code. I am now looking for something like this with Java, but I'm in need of something very simple-- I'd like to be able to diagram some sample code on the Internet to compare to the structure of my own.
It's a guess, but BASIC and Paradox - and don't take this in a demeaning way - sound old and my guess is that UML wasn't around when you used these languages and the diagramming tools you mention. 'Reverse engineering of code' is in most cases a functionality you'll find in CASE software (Computer Aided Software Engineering). Such software is in 99.99% of the cases capable of handling UML but also other standards like the more recent BPML etc.
I can't promise you'll find exactly the diagrams you're looking for but possibly one of the models in UML (or other standards in the tool you try out) will come close enough for you to work with.