Effectively, yes. It sounds like it was basically a rewrite. The book of journals for the game development that lots of other folks have led to talked about the process of finding a programmer to do the work in a fair bit of detail. Like everyone else has said, the journals are well worth reading. Best money I've spent on an e-book this year for sure.

In those days it would have been almost certainly rewritten. Although it would maintain a lot of similarities.