Hi,
Bill Knight schrieb:
I understand the recent M$ issue with the DOS FS is the defense of
their patent for long filename support. For the embedded stuff I
do, long filename support is something that I can live without.
The FAT is more than 21 years old and a patent has a lifetime of max. 21
years. So only some new features can be protected.
Another point: The patent law is a commercial law - if you use patented
things not commercially there are not restrictions by the patent law.
And in a worst case scenario you can use a special task group of a
research institute which is developing only workarounds around existing
patents ;-)
A couple of projects ago, on a different processor, I found and updated
a public domain DOS file system by Philip Erdelsky. We used it with a
CompactFlash card but the lower interface of the package just needs
read & write sector routines. If anyone is interested, let me know.
I'm interested. Can you post/mail a link?
In my last mail i forgot to say that the MMC example code works on the
MSP430F149 (2 k RAM) and is not tested with less RAM (maybe the limit is
1 k RAM). With the code i've written in a company it's no problem to
read/write the registers and to read/write n (=1..512) bytes from/to
address m (=1, 2, 3, ...) although the low level read/write can only be
done in aligned 512 byte big blocks ;-)
It's not easy to write code which works with (nearly) every card because
the cards are far away from the MMC specification; code which does only
what the specification says does not work. And some parameters are
experimental values because some times are not limited in the specification.
Regards
Rolf F.
