Hi, not sure if this topic has already been addressed elsewhere (sorry but I haven't checked) but I have a source code that complies and runs fine on my 32-bit linux platform, however, I now need to get it working on a new 64-bit OS. The code is quite long and has around 20 subroutines so rather than posting fragments of the code here (not yet anyway) I was just hoping to get some general advice on converting source code from 32-bit to 64-bit: things like any additional header files that may be required and declaration of variable types. Hope someone can offer some advice and point me in the right direction. Cheers.