Hello,

I think you are right in your conclusions, you have reached
flash memory limitation.

Since SD card is removable media it should be "optimized for removal"
so Palm OS VFAT driver shouldn't provide any lazy write cache.
I see the following filesystem areas to be updated then you are
writing to the card: FAT and DirEntry (FileSize and Last Modification
Date/Time).

First of all - use memory buffer. You can reduce number of writes and
increase your card lifetime by writing in 64K blocks. This would save
your card according to my calculation for 8 years.

Avoiding updating File Size and FAT is relatively easy. Just create
BIG file, add some signature to the each record (change it each time
you restarting logging, you would be able to determinate end of
current logging session) and write file without changing its size.

However this wouldn't solve Modification date/time problem if Palm OS
updates it after each write.


Friday, February 13, 2004, 10:00:28 AM, you wrote:

DFd>    My question is, what am I missing?  I don't open
PDFd> and close the file except when I complete a logging
PDFd> session, so I am only doing 1 write during each
PDFd> pass through the card, right?  Or is the FAT updated
PDFd> each time the file grows by 300 bytes, even though
PDFd> I don't close or flush it?  I really can't afford to
PDFd> buy a new 256mb card every two weeks.  Any help
PDFd> would be appreciated.

Best regards,
Dmytro Pohromskyy                          mailto:[EMAIL PROTECTED]

---
Softick PPP - Win32 PPP server for Palm OS USB connection.
http://www.softick.com


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