This is off Iomega's Web page with some minor formating.  Their table
is
sorta screwed...


Ian 


                   105      150        230      ZIP 100
------------------------------------------------------------------------
-------
Num cylinders    2,584    3,680      5,591        2,406

Num of alternate     2        2          2            2
cylinders

Total Physical   2,586    3,682      5,593        2,408
sectors

Number of            2        2          2            2
heads

Sectors per         40       40         40           40
track

Rotational       3,600    3,600      3,600        3,600
speed

Total Blocks   206,720  294,400    447,280      192,480