🚀 go-pugleaf

>I just received RISCOS3.1 two days ago. After installing it I started up my
>computer and everything seemed allright. However when clicking on my IDE filer
>icon I got the strange error: Error from IDEFS Filer : Disk not Understood
>- Has it been formatted? I tried to set one IDE drive in !Configure but that
>resulted in another icon and a bad drive error when clicking on it. It seems
>that the two modules IDEFS and IDEFSFiler are loaded from my interface but
>this also results in having two configure options for IDEDiscs. Can someone
>please explain what is happening? I have a A410/1 with an IDEA harddisk 
>interface from Ian Copestake Software and SF & PS. The harddisk is a 120mb
>drive from western digital. Please mail me any comment or thoughts, or if
>you think others will benefit also post!


I think you may be falling foul of the same problem that I did with NexusFS
partition formats.  The version of FileCore in RiscOS 3 does rather more
serious checking of disc format parameters than it used to.  In particular,
it checks that the LinkBits field (what I call IDlen 'cos I'm awkward) is
big enough to cope with the map size.  It does this with a simple
calculation of the number of bits in a map zone times the number of zones in
the map (just ignore the jargon for now).  I (and probably Ian Copestake
Software) took into account the fact that the first zone is rather smaller
than the others.  This means that at certain crucial sizes, which depend on
exactly how you have formatted your disc, I round the size of LinkBits one
way when FileCore rounds it the other, whereupon FileCore produces this
error message.  If you mail me a hex dump of your boot block (disc address
&c00 to &e00), I will try to confirm this; unfortunately since I an *very*
busy at the moment I cannot guarantee to have the time to do this for
several weeks, so you may be better of asking Ian Copestake Software.


The only thing that I can suggest is that you put your RiscOS 2 ROMs back
in, backup everything on your hard disc and then reformat it as if it were
slightly smaller.  Yes, I know this sounds silly, but the real fix needs to
be done to the IDE format program, and I really do not recommend that to
anyone who is not intimately aware of the innards of the disc formats! 
There is just far too much to break.

---
Rhodri James                   *  Disclaimer:  These opinions are shareware,
SJ Research Ltd, Cambridge     *    and may only be used if you send off
Rhodri.James%gb.INTERSPAN.sj   *    $100 registration fee in used fivers.
            @mhs-relay.ac.uk   *    SJ Research is not registered with me.
   or                          *
rmj10@phx.cam.ac.uk            *             Wombats are go!