Hi Saleem, > - OS << format("; vsp = vsp + %u\n", 0x204 + (Value << 2)); > + OS << format("; vsp = vsp + %" PRIu64 "\n", 0x204 + (Value << 2)); Aren't there some issues with MSVC around those macros? That is, I didn't think it supported them at all. Cheers. Tim.