a task switching application that lets you swap out one program and switch to another

That's not (and will not be) supported in any way, those programs have to
save back/restore lots of internal dos tables that are not present in dosbox,
so it simply doesn't work. If it *seems* to work (old versions) don't give too
much about that because arbitrary bugs may occur later on.

Thank you for that explanation! It probably also explains why WordPerfect for DOS 6.x locks up DOSbox when it's "launcher" program is started in high memory, but not in low memory; the launcher is used for swapping out the main WP program when various utilities get run instead.

Thanks again for sorting this out. Of course I wish DOSBox would someday support this kind of thing (because DOSEMU won't ever be ported to Windows or OS X), but I understand why it won't.

It should work when booting msdos (probably freedos as well) inside dosbox.

You're right about it working with MS-DOS, but of course the great thing about DOSBox in its default mode that it can read files from the hard disk, which it can't do when running MS-DOS. I haven't tried FreeDOS with this. I know FreeDOS has trouble with WordPerfect 6.2 launcher, but the Shell program seems to work under FreeDOS in DOSEMU.

Thank you again for the information!