The current source can access any data from any location, there's no real structure or relations between objects and classes.
Mostly you'll probably want to work from the main loop, wich I think is found in HDRoutines, so you can see when the different modules are put to use.
But you still can't see what's realy going on from there, so to get the full picture you'll probably have to do a lot of digging.
Also rob is short for robot, this actualy threw me off when I was messing with the code Theres an array with all the robots, and a robot object contains a very large amount of poorly structured data for the robot, helps to take a look at that (This part actualy has some rpopper comments explaining which is what, so it clears up a few things, and raises more questions ;P )
And if you come across an attempt to implement a linked list of robots in there, turns out it's legacy and is never used. (Spendt some time staring at that too)
Other than that good luck, with the lacking structure I recommend using searches to track the vars you need to follow and such...
And ofcourse if you feel like you have WAY too much spare time, then restructuring (Or rather, structuring) DB2 completely would make it a lot easier to work with
Oh and one thing about VB6, it's syntax is pretty straight forward in most cases, but it has some ugly syntax aswell IMO.
No brackets, you end an if with EndIf, you end a for with EndFor, and for some unexplainable reason they felt like breaking their own standard and chose to end a while with WEnd...
Also if you get tired of getting a popup when leaving a line with an error in it then you can actualy disable this, can't remember the name of the feature you need to disable, it's one of those precompiling things.
Also when making changes while your code is running remember that you risk not having initialized vars correctly and that errors you got during your first loop could affect the following ones.
So if your code behaves oddly I definately recommend rebuilding. The whole dynamic interpretter or whatever they call it is a cool feature, but it can also be very unreliable in some cases.
So IMO you got your hands full, VB6 isn't too hard to pick up, but the syntax isn't exactly easy on the eyes, and DB2 has no real structure or dokumentation, so you have a sort of programmers archeology task ahead of you
And thanks for actualy bothering with DB2 I thought everyone had given up by now...