If anyone\'s interested, I got it working. Did a format to get back to factory config, installed Exult, LibSDL etc, this time I found the .exult.cfg (finally remembering that the leading \".\" means \"hidden\" DOH!), gritted my teeth, ran vi (experiencing the vague state of panic that usually ensues when using vi) and simply replaced all instances of \"homeroot\" with \"homezaurus\" and she now runs like a beaut.
May I just say how awesome it is to have Ultima on a Zaurus. I was a great fan of Ultima Underworld 1 and 2 on the PC (2 is, in my opinion, one of the most immersive and epic games of all time), always wanted to play the top-down adventures but never managed it since running games in DOS had become difficult by that time. Now I finally get to play the best of them all. On the bog!
Thanks and congratulations to the Exult team.