Date   : Fri, 14 Sep 2007 14:45:33 +0100
From   : julesrichardsonuk@... (Jules Richardson)
Subject: Working out disk sizes...

[probably an obvious answer - I'm not next to a BBC with which to check]

Armed with a BBC that's both DFS and ADFS-capable, what's the most painless 
way of working out the geometry of an unknown floppy:

   1) Filesystem type, side 0 (DFS, ADFS, unknown)
   2) Track count, side 0 (40 or 80)
   3) Filesystem type, side 1 (DFS, ADFS, unknown)
   4) Track count, side 1 (40 or 80)

... just trying to bring up a catalogue using the appropriate ROM (DFS or 
ADFS) seems like a good start, however I'm not sure if it's obvious from the 
catalogue data whether a disk (DFS or ADFS) was formatted 40 or 80 track?

Furthermore, doesn't ADFS have the option of spanning both disk surfaces - is 
it obvious from the side 0 catalogue of such a disk that the second surface is 
an extension of the first?

(JOOI, what was the definitive ADFS reference for the 8-bit machines? Whilst 
DFS seems to have been covered in specific books from both Acorn and others, I 
don't think I've ever come across any equivalent for ADFS)

cheers

Jules