[Simh] Disk info request

[dundas at caltech.edu]

Timothe,

> In the process of debugging the ODS2 utility, it became clear that the
> disk geometry really does matter.
> And it's not available in simulator images -- or even for physical
> devices -- at runtime.

I've done quite a bit of hacking with ods2, at least enough to get it to
do what I want.  What do you want it do to?

Disk geometry isn't needed to read files on an ODS-2 volume IFF the first
home block is intact.  Indeed, if the first home block is damaged and you
need to find another, you need to initialize a disk, you want to read an
ODS-5 volume, or some other operations, you may need the geometry.  If the
home block is good, it points to everything else needed to read a
non-corrupted image.  If you can get that far, the SCB in the BITMAP.SYS
file does contain the geometry (at least the parameters VMS initialized
the volume with).

John