Yes. You have to get it separately, though. You can do this either by attaining the patch and applying it to the regular version, or you can get the pre-patched version.
And to elaborate a little on Bunsen's answer: Yes, a Zip100 disk will work in a Zip 250 drive, except that it will operate more slowly than a Zip250 disk would in the same drive. There may be a few unforeseen reliability problems, too, but I don't really have much experience in that regard (I always use Zip100 disks in a Zip100 drive).
Also, this only works on SCSI Zip drives, as far as I know.
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