I remember the game crashing or hanging in (real) DOS before or during the appearance of a boss, or the boss not appearing at all, or getting stuck at a certain unreachable location. Though you might experience a DOSbox problem (it shouldn't crash of course), the cause is probably a bug in MSBoD.

JAL

Thanks for replying.

The game does indeed freeze up completely when I try to run it using a DOS bootdisk, but I definitely remember that it ran properly back on my old 486 or so.

If Zone 66 (which was very strongly dependent on features in old hardware) can be made to work, perhaps getting this to work would not be impossible either?

Well, I searched the net and found many versions of MSBoD, mostly the unregistered version. One version was registered, which allowed me to play up to level 21, and on one occasion, the boss did not appear (I went to round 22) and on one occasion it did (tried twice), but I vaguely recall that's not unusual behaviour (when hitting the boss off screen, it disappears instantly, so hitting it just before/when it appeats is enough). So it seems at least a version works correctly with DOSbox. I appended a ZIP-file with the working version, hope that helps.

Edit: the enclosed version isn't registered either, but just a very old version that asks you to register without interfering with the game play 😀.

JAL

for Zone 66 you have to set:
xms=false
ems=false