[Simh] Mounting simh disk files in Linux

[Johnny Billquist]

On 2016-03-03 17:21, Timothe Litt wrote:
> 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.

I should check, but I'm pretty sure the home block copies for ODS-1 is 
at 256, 512, 1024... Logical block number. So not based on geometry at all.

But let me check later tonight, to be sure...

	Johnny