help building PHP4b4pl1/Win32

As others have, I'm getting the message "bad address" from bison when trying to build PHP4b4pl1 on Win32 (NT4WS SP6a, VC++6 SP3), both in the IDE and from DOS. The solution that's come up on this list is to make sure that c:\tmp exists, which I've done (all my volumes have \tmp). bison.exe reports its --version as "GNU Bison version 1.25". Is there any more lore on how to get around this problem? (Other than getting familiar with things, I don't think I really need to build all of PHP. I'm just interested in making an extension .dll. The way to do that has been asked here before, but with no answer. Any guidance?) Thanks for any help. *** Mike O'Regan moregan@mcs.net (Chicago, IL, USA)