Open up a shell and type 'setconfig dosmount "
". Once you've done that soft reboot and you should have access to your fat partitions through amigaos.
If that doesnt work you'll need to install fat95, but if memory serves me correctly it's unnecessary with a lot of hardware on amithlon. It's been a while since I set things up from scratch and did most of this sort of initial setup tweaking a while ago, so it's a little hazy 
Anyway, let me know how using setconfig goes. It's can be a little crash happy when mounting the drives/partitions this way, but only needs to be done once per session and drives will appear with all susbequent soft reboots, so its not too much of an issue.
