System 8.5.1 and PC Disks = file corruption?

[David Bainbridge]

This is a problem with a commerical program I am responsible for. The
progam is cross-platform so the same data file will open under the
windows or mac version.

Is there any known problems with system 8.5.1 and programs saving files
onto a PC formatted floppy disk? When you open one of the data files on
the pc formmatted floppy disk that was last saved on the windows side,
then choose "Save" from the file menu, overwriting the original(this is
not a safe save), the file will become corrupt(a few extra lines of
garbage or lines missing). If you do a "Save As..." and save it as a
new file on the pc formatted floppy disk then the file is NOT corrupt.
If you copy this same file onto a mac formatted floppy disk/hard disk
and do a "Save" the file will not corrupt.

If I setup the "file exchange" control panel so that it interprets the
windows/dos file extension to the equivalent mac file type, then tI
can't even open the file. The file will crash with a -116 error.

I am not sure if this happens in 8.5, 8.1 or 8.0 yet but this definetly
was not a problem in any of the system 7 versions. If anyone has any
idea please let me know...

David Bainbridge
d...@netins.net

[Michael]

David Bainbridge <d...@netins.net> wrote:
>>
Is there any known problems with system 8.5.1 and programs saving files
onto a PC formatted floppy disk? When you open one of the data files on
the pc formmatted floppy disk that was last saved on the windows side,
then choose "Save" from the file menu, overwriting the original(this is
not a safe save), the file will become corrupt(a few extra lines of
garbage or lines missing). If you do a "Save As..." and save it as a new
file on the pc formatted floppy disk then the file is NOT corrupt. If you
copy this same file onto a mac formatted floppy disk/hard disk and do a
"Save" the file will not corrupt.
<<

I had a similar problem with files getting corrupted when re-saving them
to PC formatted floppy disks. It started with Mac OS 8.1 (the corruption
did not happen with the same code in earlier versions of the OS). I
"fixed" it by calling PBFlushVol immediately after writing the file to the
disk. Give this a try and see if it helps.

- Mike