At long last, I have managed to make some progress on Doors CS for the TI-83+. I discovered what the bug was: all routines worked fine, but as I suspected, there was an underlying problem in what it was doing. It needed to swap the program to higher mem than Doors CS, not lower mem as it needs on the TI-83. I now need to devise a routine to swap it the other way around so that the calculator won't crash if prgmZDCS is in high memory. This should take a relatively short time, and I look forward to a projected release date in the next two weeks. The current beta (beta 3) can be found at the Doors CS Member Page.