OK, I've made some progress on my own, but I'm still stuck. I've learned that application data lives under /home/zaurus/Applications/dtm. So if I can get the home partition mounted on my desktop, I should be able to just copy the files out, and then transfer them to my C860.
I've also found this
script, which seems to be an update of the earlier mentioned one with the proper values for ROMs from C700-C860.
This
thread supposedly shows how to create the MTD device to hold the partition image and then mount it, but none of the three partition images work. I get either something like "Can't find superblock" (last night) or segmentation fault (tonight).
All the modules as well as the jffs2 module loaded fine. I'm running FC3, reasonably updated. Kernel 2.6.10, Athlon 2800.
Help, please! Are these in fact jffs2 images, and if so how do I mount them?