Starting Windows XP SP2 in 3150 (after 1970) - F8 / Enable VGA mode did the trick
Answering my own post - http://forum.parallels.com/thread8669.html did the trick: Pressing F8 during Windows start up, then selecting Enable VGA mode allowed to start up Windows XP, then I could install the new Parallels Tools, and now it seems 3150 is up and running - great!
Last edited: Feb 12, 2007