D7) Will the protection systems in DR DOS work against viruses?

Partially.  Neither the password file/directory protection available
from DR DOS version 5 onwards, nor the secure disk partitions
introduced in DR DOS 6 are intended to combat viruses, but they do to
some extent.  If you have DR DOS, it is very wise to password-protect
your files (to stop accidental damage too), but don't depend on it as
the only means of defense.

The use of the password command (e.g. PASSWORD/W:MINE *.EXE *.COM)
will stop more viruses than the plain DOS attribute facility, but that
isn't saying much!  The combination of the password system plus a disk
compression system may be more secure (because to bypass the password
system they must access the disk directly, but under SuperStore or
Stacker the physical disk is meaningless to the virus). There may be
some viruses which, rather than invisibly infecting files on
compressed disks in fact very visibly corrupt the disk.

The "secure disk partitions" system introduced with DR DOS 6 may be of
some help against a few viruses that look for DOS partitions on a
disk.  The main use is in stopping people fiddling with (and
infecting) your hard disk while you are away.

Furthermore, DR DOS is not very compatible with MS/PC-DOS, especially
down to the low-level tricks that some viruses are using.  For
instance, some internal memory structures are "read-only" in the sense
that they are constantly updated (for DOS compatibility) but not
really used by DR DOS, so that even if a sophisticated virus modifies
them, this does not have any effect.

In general, using a less compatible system diminishes the number of
viruses that can infect it.  For instance, the introduction of hard
disks made the Brain virus almost disappear; the introduction of 80286
and DOS 4.x+ made the Yale and Ping Pong viruses extinct, and so on.


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