DOS Merge -- "access denied"

[Brian D. Horn]

In article <1990Aug28.180409.22536 at athena.mit.edu> dyer at arktouros.mit.edu (Steve Dyer) writes:
>One apparent consequence of this is that it is not possible
>to run more than one copy of the application on the same PS/2
>at a time.  That is, if I start up two copies of DOS Merge
...
>Exactly what the problem is is isn't very clear, but
>it seems to be at the interstices between DOS/network
>drives/UNIX protections and DOS Merge's emulation of
>same.  The developer of the Clipper application reports
>that he can run multiple copies on a network provided
>that the EXE is set to be 'read-only'.  Well, setting
>this attribute under both UNIX and DOS has no effect here.

	Forgive me if I am a bit fuzzy, but as I recall DOS tries to
do a DOS file lock on "writable" images.  With Unix providing the file
system access to the EXE the concept of a "writable" image becomes a little
vague and hence almost ANY write access will do.  The DOS lock (I believe)
becomes a Unix enforced lock and hence the second DOS session trying
to access the EXE is denied access.  There SHOULD be a way of marking
the EXE as read-only (but I cannot recall exactly how) as suggested by
the Clipper developer which would defeat the locking and let you run
more than one copy.  Perhaps Dana Myers can answer this question better.
(I went looking for him, but "no joy".)