[Simh] Mounting simh disk files in Linux

[Timothe Litt]

On 03-Mar-16 11:12, Johnny Billquist wrote:
> What does the physical disk geometry have to do with Files-11?
> At least ODS-1 couldn't care less.
>
>     Johnny
The home block search sequence - for both ODS1 and ODS2 - uses the
geometry to determine where the HOM blocks are located.

Usually block 1 is the primary HOM block.  But the spec requires a
backup HOM block, and the search sequence varies based on the geometry. 
It was an attempt to search in 3 dimensions to avoid probable media
damage scenarios.  Think of each attempt as a rotation, move inward and
up.  But there are special cases.  Read the spec for details.

If a reader insists on finding the second (or subsequent) HOM block, it
can't without the geometry. 

The geometry is also (sometimes) used for file placement, which a reader
shouldn't care about.



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