You may want to try Microsoft VirtualPC or VMWare, both have full-featured trial versions. On one occasion I had disk utility that refused to work on the host Win2000 machine but did not have any problems running under Win98/DOS inside VirtualPC on the same machine. Of course, that depends on the level of tricks the software is doing. If it is BIOS-only, you have a good chance but if it attempts to program FDC controller directly -- just forget it.
If you get it working under any virtual machine then it should technically be possible to modify DOSBox to do it as well. It may be that it is just using some BIOS function that is not implemented or incorrect in the current version.

Gielber utilities says that they access the disk directly, bypassing DOS - since the utility must use it's own method of reading the proprietary diskette format. Under normal DOS or Windows XP those diskettes appears to be empty. So I would, I think, need to utilitize something that permitted that type of hardware access.

Runtime 200 = Borland lame speed test. There are some patch for fixing that issue, and you could exec that utility in your DOS boot.

Also, you could use WinImage to make a raw image of your disc, and feed that to DOSBox (use imgmount).

Hint: Runtime error 200 is triggered by a division by zero or too fast computer. A computer under 200 mhz will run that software easily, but VMWare or VirtualPC will fail (too much speed).

Update: I have a program to fix Runtime Error 200 (TPPatch). Search in google and give it a try.

Also, you could boot in DOS and use Moslo to slow your computer under 200 Mhz and get rid of the error.

Sounds like you'll need to dual-boot to Win9x or DOS then, as no modern OS is going to give programs that level of control over the floppy drive. The image idea may work, but you'll probably need to boot DOS or Win9x to make the image.

I guess the BIOS is not the problem, the format of the disk is the problem. DOSBox expects that Windows will read the files in the disk, but won't read the disk sectors directly (I'm assuming that your disk haves have 2 sides, 80 tracks each side and 9 or 18 sectors each track... so the disk is NOT FAT formatted).

So I think that if you make a raw image (i.e.: read all sectors and store them in a file) it would be readed by DOSBox.