I have only owned my Newton for a couple of months now, so the results of any experimentation beyond printing a document to my LW300 & SW1500 will be interesting. I do have a din-8 to db-9 cord, however it no longer works (I tried hooking up my ImageWriter II to the HP PC using the C-Itoh 8510 driver, but it would not print out a document). I have been trying to look for a replacement, but so far no success (I have gone to the Source, Best Buy, Staples, etc.). I will take a look at the link you provided.
According to Apple, Newton Works is 100% compatible with the Windows operating system. I have yet to confirm that, however.