Again this fake quote? I know it’s justa mindless copy-and-paste, but at least put it into context. Marx never wrote that. Here’s page 651 of the Moore translation, and here’s a discussion of the origin of that quote.

They were shipped in z-code, but z-code is basically machine code, and indeed, you can patch any game if you want to fiddle with the binary. The source code is human-readable.