Walter
Thu Feb 05 05:28:14 CST 2004
peng wrote:
> I have developd a driver to read CPU cards ,now I want to develop a driver
> to read memory cards .But?
> what is the maindifference between CPU cards and memory cards while
> developing drivers??
> can you offer me any key opinions on developing the driver to read memory
> cards.
The biggest difference is that the PC/SC standard doesn't specify the
top-edge interface (that is, the IOCTLs that an application would use)
for accessing memory cards. Since every memory-card application requires
unique user-mode software anyway, that's not a big handicap. Most
vendors just dream up a sensible (or not) scheme of their own.
The lower edge of your driver (that is, how you talk to your reader)
totally depends on how you design your reader. If you've built a USB
reader, I hope you followed the CCID spec. If so, you can define all the
escape commands you like and use them to access memory cards. I believe,
however, that you would also need to build your own driver (hard!) or
purchase one from a third party vendor (Ahem!), because I don't think
Microsoft's driver provides any way to do escape commands. If it's not
USB (or it's not CCID compliant), dream up a protocol that you can
implement easily in firmware, and then program the driver to use it.
--
Walter Oney, Consulting and Training
Basic and Advanced Driver Programming Seminars
Check out our schedule at
http://www.oneysoft.com