Date   : Sat, 15 Sep 2007 15:25:56 +0100
From   : splodge@... (Richard Gellman)
Subject: Working out disk sizes...

David Harper wrote:
> It is, of course, quite possible for a disk to be formatted in ADFS on one 
> side and DFS on the other. The "front" could be ADFS "small" or "medium" and 
> Drive :2 could be formatted DFS (though you cannot do it the other way 
> round). I don't know whether anyone has ever been eccentric enough to do 
> this, but it is quite possible and "legal".
>   
Eccentric Sir?

I'll have you know all the lampshades are on my submarine!

Meanwhile, I used to do this when I first started converting all my DFS 
disks to ADFS. Format drive :2 to DFS, then use *COPY to copy the files 
from :0 to :2. Then format :0 as ADFS small or medium (40 or 80 track), 
then use CopyFiles (off the Welcome disk) to transfer everything back 
from :2 to :0.

The advantage of this method is there's no disk swaps (except to load 
CopyFiles). It does however require that the disk is in pristine 
condition.... the neurotic ADFS formatter on the Welcome disk doesn't 
understand the concept of "been around for a while"  and instead of 
mapping out bad sectors like modern formatters (yes, ADFS can do this by 
removing them from the free space map, it just means you can't compact 
it. This is what HardError on the Welcome disk does) it aborts the 
format completely before it gets to the stage of writing the catalogue 
and free space map.

Anyway, as a result of all this foolery, I now have a number of disks 
that are 80track ADFS on drive 0, and 80 track DFS on drive 2... usually 
with much the same contents in both.

-- Richard