Just FYI.
Tried out the DOS versions of Fred Chlanda's Unshp/Mkshp/Hdshp programs in DosBox today and got this error message.
"Load error: no DPMI"
Then noticed on his homepage this program called CWSDPMI:
http://hosted.wargamer.com/ChlandaWorkshop/misc/cws.zip
Downloaded and run it in dosbox before starting unshp.exe and it worked!