On Thu, 2008-01-24 at 14:12 +0000, Peter Clifton wrote:
> Hi,

> I've been looking at the pin-out documents, and don't see many (if any)
> uncommitted lines, then again.. I'm not really following Chris Jones'
> documents that well.
> 
> Ethernet is a real desire, so I'd not like to re-use any data-lines
> which would stop the CF socket working. USB would be nice to have, but
> if any other features could be sacrificed in exchange for more IO, that
> would be something I'd consider.

Moving away from the Samtec pinout and looking deeper at the schematic,
I see that the samosa bus might be useful for my application.

I'd started to think that the D0-31, A0-24 lines on the Samtec were
pretty much uncommitted, but I now note they are the same data-lines
used by the CF socket.

Can anyone who's constructed motherboards or accessories for the
Balloon comment as to how extra functionality such as Ethernet
controllers are added, and what IO pins are used? I realise can't share
in my application (I need control over the line), but can the address
and data lines of the CF socket be shared with other addressed and
chip-selected devices?

In the future, I'd really like to have on-board Ethernet, so if most
Ethernet controller chips require a good complement of address + data
lines, perhaps I'll be stuck using the number of signals on the samosa,
even if I can fore go support for the compact flash socket.

Are there any schematics or design documents for motherboards I could
look at?


Best wishes,
-- 
Peter Clifton

Electrical Engineering Division,
Engineering Department,
University of Cambridge,
9, JJ Thomson Avenue,
Cambridge
CB3 0FA

Tel: +44 (0)7729 980173 - (No signal in the lab!)