I want to debug my program I wrote in NASM by using OllyDbg. Without that, OllyDbg does not label the functions by their correct name, and leaves them as unnamed functions. OllyDbg accepts PDB files (the same file type exported by VB6 when it compiles an EXE), which would store the function names, so as to make debugging easier. Does NASM allow the exporting of Visual Basic format PDB files? By the way, PDB means Program Database, if I remember correctly. I'm not sure if it's only a Microsoft thing, or an industry standard format. It contains info to allow debuggers (such as OllyDbg) to keep the names of functions, so that it's easy to see when a particular function is being referenced in the code.