Date   : Sun, 22 Jan 2006 02:32:46 +0000
From   : "Ian Wolstenholme" <BBCMailingList@...>
Subject: Re: eBay What is this?

Success...well, to a point.

I used the Xebec manual to write a little initialise & format routine
and used the write map & write dir routines from Superform.  It worked
and gave me a disc appearing to be the correct 20MB size, although 
any attempt to access disc sectors beyond about the 5MB mark gives a disc
error.  So the controller is forgetting that I have reset the drive
parameters and reverting to the standard ones, or it could be that the
initialise routine didn't work in the first place.

I haven't worked out how the Xebec board deals with bad sectors and
defect lists.  With the Adaptec one you can point to a defect list in the
parameter block sent by the format command but I can't see any reference
to this with the Xebec one.  Fortunately the Seagate drive I am using is
a physically perfect disc.

I have the older firmware in the Xebec board, number 104788.  According
to the manual, the "enhanced option" number 104793 stores the params
on the drive like the Adaptec controller, so that would be ideal if anyone
has a ROM image of it!

Best wishes,


Ian

----- Original Message -----
From: Jules Richardson
To:   bbc-micro@...
Sent: Sat, 21 Jan 2006 22:54:54 +0000
Subject: Re: [BBC-Micro] eBay What is this?

Ian Wolstenholme wrote:
> I was after the bridge board more than anything, there's a real shortage
> of them round here

Yep, they're not *that* common - most of them ended up in either add-ons for 
home micros (and of course they were hugely expensive), or mid-range Unix 
workstations (which often came equipped with SCSI controllers, but used ST506 
drives to keep costs down)

 > and I was slightly intrigued by the possibility of the drive contents.

Sure - so am I! :-)

> It's the first bridge board I've seen on E-Bay apart from
> ones which will obviously be inside officially packaged BBC Winchesters 
> like Cumana or Technomatic ones.

Yep, not the sort of thing that people would sell separately I suppose. I 
think all of my loose ones were Torch ex-workshop spares; everywhere else I've 
only ever seen them with drives in an enclosure...

> A scan of the Xebec manual would be handy, or just the details of the
> initialise command (12, &C) parameters should get me going.

See Jon's post; seems like it's around on bitsavers already! :)  My manual's 
for revision E firmware (should be stamped on top of your board's EPROM) so 
it's got a supplement in the back of the manual that covers the changes 
between rev. D and E. Yell if that's what firmware you have and you think it 
may be useful.

Actually, my manual's for a S1410, not an S1410A - I'm not sure what the 
difference between the two is...

> I am not sure how I would get any data off the drive.  If anyone can point
> me to a programme or routine which will do it then I will see if I can get it
> copied onto some other media.

I'm sure it must be possible on the beeb somehow - once the drive geometry is 
set up the board should appear like a SCSI disk and a normal read command can 
be used to read raw sector data from the drive. *Hopefully* the SCSI code in 
the ADFS ROM is separate from the filing system code, so that there's a way to 
do a raw read from a device that doesn't have ADFS on it...

I've got some hardware thrown together to talk to one of these cards from a PC 
parallel port, but I haven't had time to write any software to drive it yet - 
hopefully soon!

cheers

Jules