Been looking back at the Fujitsu FM-Towns driver lately, and been successful to some extent in getting it to do something useful. Now it passes the RAM test successfully, and managed to stop it from returning to an empty code area. Now it fails on checking the CD-ROM drive. Oh, and there's basic video output also now, so you can actually see just what it's testing. Still a very long way to go on this one, but progress is progress.