Re: [iPAQ] SD Card protocol specs

On Thursday 27 February 2003 09:12 am, Nils Faerber wrote:
<snip>
> > However, an SD driver would still be preferable because MMC cards tend
> > not to be available in such high capacities as SD.
>
> And additionally think of the new multi-purpose SD cards, like camera
> (OK, not particular useful :) Bluetooth and even WLAN. Those would be
> really interesting and are IMHO SD only wothout a MMC compatibility
> mode.
>
> > p.

And therin lies the rub: it's fairly trivial to get SD and MMC _Memory_ cards
working in a given driver. What seem to be the major stumbling blocks for SD
only development are:

1. Proprietary interface hardware (e.g., Zaurus)

2. Every manufacturer implementing proprietary communication protocols for
their SD/SDIO devices.

This is true even for something simple like getting a SD memory card to work
in 4 bit data mode. Why this has to be a deep dark secret guarded jealously
by every mfr is anybody's guess.

Given that the whole SD mess seems to have originated with the usual
pin-headed nit-wit anal-retentive entertainment industry types I don't see
much hope for getting all those nifty SDIO cards working in an open source
environment.

-- 
  Jeff Sutherland, Accelent Systems, Inc.   <http://www.accelent.com>
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Kodachrome: After nearly 70 years there's still no better way to
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