"Formatting" flash memory

Andy_P · Posted: Wed May 21, 2008 1:22 am Post subject: "Formatting" flash memory

Nearly had a disaster today...

I was trying out a bit of tweaking and had a computer glitch whilst loading to the Go which corrupted my 720's internal memory.

No problem... I have lots of Explorer backups, including one made 5 minutes before I started playing.

Started reloading and it chugged away for about ten minutes and then crashed the whole PC.
Tried again but now it kept saying "Cannot complete write. I/O device error"
Re-booted PC again, but as soon as I connected the Go, everything slowed to a crawl.

Decided to cut my losses and start again. Left the backup re-installing while I went to get a cup of tea, came back to find "Cannot copy cline.dat" Various messages along the lines of I/O error, corrupt file etc. etc.

Tried again, same thing happened.
Tried again with a PREVIOUS backup. Still no go.

Starting to sweat a bit by now...

Eventually I managed to coax it back to life by copying from today's backup, one folder at a time!

This is the first time I've ever had any problem like this, and I've reloaded backups LOADS of times.

Now... one thing I considered (whilst in panic mode!) was doing a "format" of the internal memory. Windows seemed to think I could, and said it was already formatted to FAT32, but wouldn't actually do it.

So, should I have been able to do it?
Is "formatting" memory as opposed to a drive possible or is it meaningless?

And the biggest question, why might I have been having so many problems today? If I'd been a new owner, I'd have been completely lost!

saikee · Occasional Visitor Joined: Apr 30, 2008 Posts: 21

I wouldn't format the internal disk inside TomTom myself.

This is my booting experience with any operating system. The disk storage has a boot sector immune to the formatting operation. Unless one knows how to connect the boot loader with the restored files one should not mess around the programs inside TomTom. Database maps, MP3, photos etc can be transferred out as they can be put into a SDHC card.

This is based on my experience of booting 150+ Dos, Windows, Linux, Solaris and BSD systems in a PC. The boot loader residing in the boot sector is not part of the filing system. A Fat32 partition, like every partition type used by the MS systems, has the first track permanently reserved as the boot sector.

46jimbo · Regular Visitor Joined: Apr 24, 2005 Posts: 185

Will your unit boot up from an SD card?

Andy_P · Posted: Wed May 21, 2008 2:56 pm Post subject:

It's all fine now (well back to normal!)
As I said, "gently" copying back one folder at a time managed it OK.

So my two questions really are:
1. Why did it start throwing up I/O errors? PC or TT to blame?
2. Does "formatting" actually mean anything on flash memory, or is it exactly the same as simply deleting everything?

Darren · Posted: Wed May 21, 2008 4:03 pm Post subject:

saikee · Occasional Visitor Joined: Apr 30, 2008 Posts: 21

I view a partition having two parts.

The first part is the overhead section with the track reserved as the boot sector. Thereafter there will be the File Allocation Table or FAT which is an indexing system to assemble the files from different cylinders, heads and sectors of the hard disk.

The actual data is stored in the second part. Since a User may delete files from time to time a new file is unlikely to be placed on consecutive sectors or clusters but selected by the controller to optimize the access speed.

In formatting the File Allocation table is erased and rebuild. Although the second part of the data proper is untouched the information is as good as dead because the files cannot be re-assembled again without the original FAT.

Darren · Posted: Thu May 22, 2008 7:35 am Post subject:

Smartdriver · Posted: Thu May 22, 2008 11:48 am Post subject:

Darren · Posted: Thu May 22, 2008 11:51 am Post subject:

Which is what I said Confused

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Darren Griffin

saikee · Occasional Visitor Joined: Apr 30, 2008 Posts: 21

Which isn't what I said. Formatting a partition is not the same as deleting files. Besides one can change the filing system to another type too, say from Fat16 to Fat32.

Smartdriver · Posted: Fri May 23, 2008 11:13 am Post subject:

Darren · Posted: Fri May 23, 2008 11:19 am Post subject:

Yep, probably best, it's giving me a headache Wink

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Darren Griffin

e61 · Occasional Visitor Joined: Aug 10, 2007 Posts: 15

Pocketgps · Posted: Sat May 31, 2008 12:41 pm Post subject:

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