How to rebuild sector 0 on MMC ?

Bart · Joined: 12 Jul 2005 Posts: 49

Hello.

I have deleted me first 512 bytes on my 8 Mb multimediacard by testing it in SPI at the first sector.

Problem is know that I wan't to apply the FAT16 on it so I can read and write on it with the PIC in FAT16 (code available on the forum)

As the pic fat16 code starts on the boot sector, with is sector 0, and as this one is zero-t, the code fails on it.

I know that by fdisk-ing it, the MBR can be rebuild. But : as I am running in XP and as my mmc reader is an integrated USB type, I can't use fdisk on it.

Even by writing zero's on the sector 0, XP still recognise it as a working (formated) 8 Mb drive.

I tryed already some fdisk alternatiefs but all needs raw DOS (or alternatief again : PC-DOS, boot from floppy or boot from CD) And as dos don't support USB ....

SO : has somebody a solution for me ? Maybe I need to write some more sectors with zero's but I don't want to distroye my mmc.

Thanks.
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Bart · Joined: 12 Jul 2005 Posts: 49

Have obtained some more info :

File Created : C:\Program Files\Media Innovations Group\ImageRecall 3\Logs\Errors02112005.TXT
02/11/05, 23:32:44 VALID BOOT SECTOR on K:\
02/11/05, 23:32:44 JumpBoot = 235,60,144, (ë<)
02/11/05, 23:32:44 OEM Name = 77,83,68,79,83,53,46,48, (MSDOS5.0)
02/11/05, 23:32:44 BytesPerSector = 512
02/11/05, 23:32:44 SectorsPerCluster = 1
02/11/05, 23:32:44 ReservedSectors = 6
02/11/05, 23:32:44 NumberOfFATs = 2
02/11/05, 23:32:44 RootEntryCount = 512
02/11/05, 23:32:44 TotalSectors = 15584
02/11/05, 23:32:44 Media = 248
02/11/05, 23:32:44 FAT Size = 61
02/11/05, 23:32:44 SectorsPerTrack = 1
02/11/05, 23:32:44 NumberHeads = 1
02/11/05, 23:32:44 HiddenSectors = 32
02/11/05, 23:32:44 TotalSectors_FAT32 = 0
02/11/05, 23:32:44 FatSize_FAT32 = 388562944
02/11/05, 23:32:44 ExtendedFlags = 53966
02/11/05, 23:32:44 FileSystemVer = 20208
02/11/05, 23:32:44 RootCluster = 1095639119
02/11/05, 23:32:44 BackupBootCluster = 8224
02/11/05, 23:32:44 Reserved = 32,32,70,65,84,49,54,32,32,32,51,201, ( FAT16 3É)
02/11/05, 23:32:44 DriveNumber = 142
02/11/05, 23:32:44 Reserved2 = 209, (Ñ)
02/11/05, 23:32:44 BootSignature = 188, (¼)
02/11/05, 23:32:44 VolumeID = 240,123,142,217, (ð{ŽÙ)
02/11/05, 23:32:44 VolumeLabel = 184,0,32,142,192,252,189,0,124,56,78, (¸ ŽÀü½ |8N)
02/11/05, 23:32:44 FileSystemType = 36,125,36,139,193,153,232,60, ($}$‹Á™è<)

Do you think I can copy the BackupBootCluster back to sector 0 ? Or is it not that simple.
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asmallri · Joined: 12 Aug 2004 Posts: 1634 Location: Perth, Australia

Have you tried putting it a camera or some other device and using the devices format card mechanism?
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