Hi Mario,

Sorry my last post was in reply to the wrong thread and is here -
http://uk.groups.yahoo.com/group/tatung_einstein/message/256

The XTal DOS version on the .DSK image from Chris' site which you
probably used to boot MESS from the first time is DOS 1.31 I can't
remember if this was the last version but you may find that this could
be your problem too.

MOS (machine operating system) is in the bios folder in MESS.
DOS (either XtalDOS or CP/M) is loaded from the disk you boot from.

They both need to be compatible with the .COM file you are trying to
run. All XBASIC programs (.XBS files) will work with the version of
XBASIC on the disk that boots if you follow the instructions on Chris'
site but some .COM files might not.

Regards,
Geoff