How to force bad blocks into CF in order to decrease the capacity
 

Hello,
I have to prepare a Master CF suitable for multiple CF duplication by using a stand alone CF duplicator (IMI M6500). The problem I'm encountering is that despite I'm using the same CF both for Master and for Copies (Kingston CF x133 8GB-2S), the real size of CF changes with the lot #. In example I have found a lot# with 7637MB and another with 7272MB. Since the CF duplicator performs a binary copy, it fails when the Master CF is bigger that the Copy CFs.

I don't like the idea to prepare from scratch a new Master for each new lot#, or to look for the lot# with the smaller size and use it for Masters.

I know that this size differences might be due to bad block management, introduced by the manufacturers in order to increase the yeld of NAND Flash devices.

I was wondering if there is a way to mark some extra blocks as bad (independently from the filesystem) in order to decrease the available size below a size that likelly I won't never find in a new CF of 8GB.

My application actually needs the following 5 partitions:

C: Pri DOS FAT16 2047MB
Extended DOS:
D: logical FAT16 2047MB
E: logical FAT16 1028MB
F: logical FAT16 1028MB
G: logical FAT16 1028MB

There are typically almost 500MB unallocated(depending of lot#) that could contain entirely fake bad blocks without effecting my application.

Thanks in advance for any suggestion
ASCA

you could specify to the "dd" command the amount of data to dump with bs and count option.

The command "dd" works fine for single CF duplication. It is able to recreate all the partitions even if the dumped data are a little less that the full capacity.
But actually I would like to have a "small size" Master CF suitable for my stand alone duplicator that is able to make 8 copies for each duplication process.