Memory Card Problems

[sillyputtyluvscameras]

:confused: I don't understand formatting... I though you only had to format your memory card once. My 256MB memory card keeps deleting the pictures and coming up at memory card error on my cannon camera. my other two smaller memory cards work fine? Am I doing something wrong? Could someone plesae explaing formatting to me?:confused:

[Rhys]

:confused: I don't understand formatting... I though you only had to format your memory card once. My 256MB memory card keeps deleting the pictures and coming up at memory card error on my cannon camera. my other two smaller memory cards work fine? Am I doing something wrong? Could someone plesae explaing formatting to me?:confused:

It sounds like a FAT error. A scandisk should fix it.

[sillyputtyluvscameras]

Okay, I'll read up on that. What's a FAT problem? Do you understand formatting?

[Rhys]

Okay, I'll read up on that. What's a FAT problem? Do you understand formatting?

FAT = File Allocation Table. When this gets screwed up all sorts of strange things happen. It's usually fixed via ScanDisk or Norton Disk Doctor. I'd recommend ScanDisk as it's part of Windows O/S. Norton used to be a good package but that was 10+ years ago. Since then it's been run down gradually by Symantic into barely functioning bloatware.

[AlexMonro]

A format of the memory card in the camera is probably the best way to fix problems. It should write an empty FAT in one write cycle to each sector of the card, so minimising wear.

I use format to clear cards after uploading the pictures to minimise write cycles, although this is unlikely to be significant for all but the hardest shooting professionals taking hundreds of shots a day.

Do make sure you've uploaded all your pictures to a computer first though!:)

To give a brief answer to your original question, formatting is marking out empty data structures so that the camera knows how and where to write pictures on the card. The most commonly used way of storing files on memory cards is the FAT filesystem, based on the filesystem used by DOS and Windows95. This has 2 main data areas, the directory, which holds the filename, date & time, filesize, and other information, and the FAT, which is a list of the actual sectors of the card used to store the file (picture).

Unlike disks, flash memory has a limited life in terms of the number of times it can be written to, typically 100,000 - a million cycles. deleting a file needs at least 2 writes, the directory & the FAT, whereas a format deletes all files in just one write.

[Rhys]

No. A ScanDisk will also mark and block bad sectors too. Formatting won't do that.

[AlexMonro]

Well, the ScanDisk notion of bad sectors is really rather outdated and belongs back in the days of MFM/RLL disk drives. Modern ATA or SATA disks don't actually handle reads and writes directly with the addresses passed on the interface - those are effectively the logical addresses, which are remapped by the on board drive controller, which also handles remapping bad sectors - transparently as far as any system software is concerned.

Flash memory cards - at least the more modern types, SD & MS, probably not SmartCard, not sure about CF - have a similar form of onboard controller, which also attempts to equalise the write cycles on the physical sectors by remapping. So you should only see "bad sectors" if the spare remappable sectors have all been used, by which time the card is pretty nearly dead.

So the best thing to do to maximise the operating life of a flash card is to minimise the number of writes, since the card has to make a physical write to correspond to each logical write command, even if it doesn't go where the camera (or computer) system thinks it is. Any software that assumes it knows what's going on at the physical level inside the card is asking for trouble.

[sillyputtyluvscameras]

Thanks for the help, this is starting to make sense...I've ordered a bunch of book from my library so I can read up on this more. Does anyone know of any useful websites for me? Thanks again, :)

[AlexMonro]

You might start by looking here:

http://computer.howstuffworks.com/flash-memory.htm
http://en.wikipedia.org/wiki/Flash_memory

[wenmang]

FAT = File Allocation Table. When this gets screwed up all sorts of strange things happen. It's usually fixed via ScanDisk or Norton Disk Doctor. I'd recommend ScanDisk as it's part of Windows O/S. Norton used to be a good package but that was 10+ years ago. Since then it's been run down gradually by Symantic into barely functioning bloatware.

How can I find scandisk utility? where is it located in winXP?

[Rhys]

How can I find scandisk utility? where is it located in winXP?

It should be in an Accessories submenu

or go run "scandisk"

[wenmang]

It should be in an Accessories submenu

or go run "scandisk"

no, it is not there. I also did search file named scandisk on C: drive, nothing either. It is not part of system tool in winXP, and not sure it is called different name or not. Also search for scndisk, yield nothing.

[Rhys]

On win 98, it's called Scandisk. For XP, try this:

Detecting and repairing disk errorsYou can use the Error-checking tool to check for file system errors and bad sectors on your hard disk.

Open My Computer, and then select the local disk you want to check.
On the File menu, click Properties.
On the Tools tab, under Error-checking, click Check Now.
Under Check disk options, select the Scan for and attempt recovery of bad sectors check box.
Notes

To open My Computer, double-click the My Computer icon on the desktop.
All files must be closed for this process to run. If the volume is currently in use, a message box will appear prompting you to indicate whether or not you want to reschedule the disk checking for the next time you restart your system. Then, the next time you restart your system, disk checking will run. Your volume will not be available to perform other tasks while this process is running.
If your volume is formatted as NTFS, Windows automatically logs all file transactions, replaces bad clusters, and stores copies of key information for all files on the NTFS volume.

[Furby]

Hi folks,

I recently purchased a Sony Cybershot DSC-T100. I inserted the battery after recharging and tried to take a photo. The message 'memory card formatting error' appeared in the viewfinder. I closed and opened the lens cover and got the same message. After closing and opening it again the camera returned to normal but all my holiday snaps had gone.

The card wont open in my PC. My PC says it isn't formatted. I've also tried to run Sony's memory card recovery tool but it keeps aborting after about 20 minutes.

Is this just one of those things or have I done something wrong?
Will the photos still be on the card?
If they are is it possible to recover them?

It would be great if one of you guys could help as I'd love to get my pics back. I've kinda written them off at the moment though.