cgd@cs.cmu.edu (Chris G. Demetriou) writes:
>> A couple of things: the Jaz doesn't mode sense, so the geometry
>> can't be `found' automatically.  A `fake' geometry works fine.

>I'm not entirely sure I believe that.  1.2.1 reported the same errors
>for me with a Jaz on a BusLogic 542B, but -current 'did the right
>thing' including figuring out a geometry.  (the geometry it figured
>out looked fake, but the sectors per unit value was correct, and i
>could believe that it looks fake in the way that it does to make DOS
>maximally happy...)

The way the Adaptec and BusLogic controllers fake the geometry doesn't
require a MODE SENSE.  It only requires a READ CAPACITY which is a
mandatory command for direct access devices.

The original method was to always report 32 head and 64 sectors per
track and dividing the capacity by 2048 (32 time 64) which gives the
number of cylinders.  The new method reports more the 32 heads, I
think, but the algorithm is still the same.

-- 
Christoph Badura

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