>   After getting the zip disk successfully formatted a/ux 2.0 free, I've
> used mkfs 1.4 on it and zapped the thing into a a/ux user slice partition.
> This is where my luck runs out.  Using the numbers I found posted here a
> few weeks(?) ago, as well as some other edu-guesses as to the geometry of
> the zip disk, I continue to get "Bad Superblock" when I try to mount
> /dev/sd1a.  Here is an example of the numbers,

Are you sure that it's /dev/sd1a?  Use disklabel and make sure that it's
not something like e,f,g, or h.  I believe that Usr partitions tend to be
lower than 'a', but I could be wrong about a disk with only a single Usr
partition.

> 
> sector size: 512
> sectors/track: 40
> tracks/Cylender: 512
> num. Cylenders: 2046
> FS Size:196430

These look ok, I believe...

I hope this helps.

Later.

-- 
Colin Wood                                      ender@is.rice.edu
Consultant                                        Rice University
Information Technology Services                       Houston, TX