> I have been trying to figure out if write-protecting CF or PCMCIA flash
> memory when mated to a CF/PCMCIA-to-IDE converter is possible and I have
> found some interesting stuff, but I am not technically proficient enough
> to decode it... So perhaps someone out there on the list could help me
> with this?
> This is from http://copper.he.net/~whiteedc/pdf/ATA10.pdf and it
> describes the function of the "write protect" pin (33) for PCMCIA ATA
> flash:
Saddly, there is no way to truly hardware write-protect a generic compact
flash or PCMCIA flash card.
The WP/-IOIS16 pin you referred to on PCMCIA flash cards is an Output. In
memory mode, this pin indicates the status of a physical write-protect
switch to the system. Since most (all?) flash cards don't actually have a
write-protect switch, this signal almost always indicates "writeable". When
in I/O or IDE mode, this pin indicates a 16 bit I/O transfer is occuring, as
opposed to an 8 bit transfer. In no case can this pin be used to
write-protect a flash card from the system side...any write protect ability
must be built into the flash-card itself.
Compact flash cards, which are basically PCMCIA flash cards in a smaller
footprint, have the same functionality for the WP/-IOCS16 pin, and are also
not hardware write-protectable by the system.
If anyone knows of a CF or PCMCIA flash card with a physical write-protect
switch, please let the rest of us know.
Charles Steinkuehler
http://lrp.steinkuehler.net
http://c0wz.steinkuehler.net (lrp.c0wz.com mirror)
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