It has been a very long time since I worked with such an old version but version 3 was a major upgrade that made the MAC and Windows versions much more compatible. One of the changes was to make the VI names the same on both platforms and another was to make the locations the same (i.e. the name of the llb that the functions were stored in. You should be able to find the equivalent functions in 3.1. Open the app in 3.1 and when prompted to find a VI, browse around until you find it. If you have a list of the VIs that couldn't be found, before opening the old app, create a new VI. Use the palette to find the functions and place them on the diagram. Then, when you open the old VI, those functions with the same name will get replaced by the new ones. For ones w
hose name changed, you'll have to manually replace those one by one. I also seem to remember a compatibility llb that was available back then. It was a set of VIs that was not part of version 3. I have no clue as to whether it's still available from NI and whether it included everything you might need. The good news is that once you're past this conversion, upgrading becomes a lot easier.
