> MBR =3D Master Boot Record. This should be at the physical sector 0

Thanks for confirming that Tamas. I've spent some of today on it but
no joy

I'm still trying to figure where the problem is

(a) the PIC - on the same voltage (3.3V) as the card and seems to
drive CLK and DO alright. Fairly sure I can rule the PIC out

(b) the card - well, sector 0 can be read, and no error is returned
when requesting sector 0x2000. But maybe the internal controller
isn't requesting 0x2000. Perhaps for some reason it's ignoring the
address I send it and somehow auto-incrementing, fetching sector 1,
which will be empty

A project I completed recently with a similar card has no problems
at all. The only difference being that it isn't partitioned (unfortunately
I don't have access to that card until the Christmas break so I can
compare). I can read its directory and retrieve any sector/file at a
good speed and with no errors

Think I'll have to go back to the SD Association's pdfs and see if
there's some nuance I've missed

The ultimate aim is to investigate 4-bit transfers, so not being able
to get it working with simple SPI is a bit of a choker

Joe
--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.