Yahoo Groups archive

Lpc2000

Index last updated: 2026-04-28 23:31 UTC

Message

Re: SD card boot sector location

2005-12-22 by derbaier

--- In lpc2000@yahoogroups.com, "theothervmax" <vmax@g...> wrote:
>
> First of all, thanks for everyone replied.
> 
> One article called "The master boot record (MBR) and what it does"
states: 
> "The master boot record is always located at cylinder 0, head 0, and
sector 1, the first sector on the disk".
> My current problem is that I can't see ANYTHING in the first sector
on my disk (SD card), as well as in the following 248 sectors, nothing
but all zeroes. Yes, I can see the volume boot sector (at rather a
weird location 249), both file allocation tables, root directory and
so on...
> I tried both FAT16 and FAT32 on this card, and the result is just
the same: boot sector number 249. 
> 

As Tom said, FAT is pretty well explained in a lot of places on the
net. The article that I pointed to certainly explained your situation
quite well to my satisfaction when I first found it. 

It does seem strange that you can't see anything on the first physical
block of the card, since the pointer to the block containing the FAT
boot record is located near the end of the first physical block on the
card right around byte 454.

--Dave

Attachments

Move to quarantaine

This moves the raw source file on disk only. The archive index is not changed automatically, so you still need to run a manual refresh afterward.