With these old games sometimes the source is just lost. I used to work with a guy who wrote Brian the Lion(the Amiga game) and he always says he wishes he still had the source code for it. We've also looked briefly at the source code of Driver, and the only one in company archives was not the final version. There were 2 revisions after that one but no one has a copy of those. And then we pulled a bunch of old CDs with assets and code burnt back in 1990s and about 50% were unreadable already, god knows what exactly was on them.