>Our largest application is currently being supported using VFP 6. However, I've traced a significant amount of the current source code back to the mid to late 1980's.
>
>My question is, considering how old some of the coding, what are the backwords compatibility issues that I am going to have to deal with when I upgrade to version 7?
>
>Is there a central site that lists all of these issues in a consolidated manner?

Mid to late '80s - man, you're talking FoxBASE+ (or even dBASE?) :-)

If you've got your code running in VFP6, upgrading to 7 should pose few problems. In the Help file you can access What's New (type "HELP WHAT'S NEW in the Command Window) and there's a section called "Behaviour Changes Since the Previous Version" which outlines what your issues may be.

Update: http://msdn.microsoft.com/library/?url=/library/en-us/fox7help/html/newWhats_New_in_Visual_FoxPro60.asp?frame=true