Sharing Dos/Windows drives from a Linux system

[Steve Cohen]

How can I do this?
I have a samba server running on RedHat Linux.  The server is actually a
dual boot machine, and has Windows drives which I have mounted under
Linux, so that /mnt/dosC is the C: drive when booted under DOS.  Also,
this machine has a Zip drive connected to it and known as /mnt/zip.

>From a Windows 98 machine connected to this machine, connecting through
Samba, I can see these shares.  I can read any file in them.  I cannot,
however, write to these shares, even though they are specified as
writable.

Is this even possible and if so how?

I have tried using fstype=FAT, or fstype=samba or fstype=NTFS to no
avail.

Here are the share portions of my smb.conf (note: MesaVerde is the host
name).

[mvD]
    path = /mnt/dosD
    comment = Drive D on MesaVerde's Dos partition
    writeable = yes
    guest ok = yes

[zip]
   path = /mnt/zip
   comment = MesaVerde's zip drive
   writeable = yes
   guest ok = yes

What must I do to be able to write to these drives over samba?