Hi! I'm the author of the incomplete BASIC version. I began writing it as a tribute when I was just starting college. No source code or disassembly was available to me at the time, of course; I just created it from observation of the original game, much as authors of arcade ports did in those days. I also made a room layout and linking editor to aid in creating the original levels which I planned to release along with the game so that others could make their own Adventures from the original building blocks.
I always intended to eventually convert some or all of it to assembly language, but college studies and other projects soon took priority. Looks like Phaeron has made short work of it now. Well done!
The Quintopus comes to mind...it was an SIO expander box that connected to one or two computers and provided an array of SIO ports for connecting multiple devices simultaneously, including "dead-end" devices such as modems and cassette recorders. Switches enabled one or the other computer to access the chain. Both could be enabled, but this only worked as long as the computers didn't try to access the same device at the same time.