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Full Version: C1000 Can Write To Sd Card... Why?
OESF Portables Forum > Everything Else > Archived Forums > Distros, Development, and Model Specific Forums > Model Specific Forums > Sharp Zaurus > C1000/3x00 Hardware
A few minutes ago I was formatting some SD cards with my Akita (running pdaXrom 1.1.0beta3).

I was on a root console, no X running. Formatted a Dane-Elec 1GB SD card just fine. I took it out from the Zaurus, put it in the card reader of my desktop computer, and as soon as I tried to write on it, the computer complained that the card was write-protected. huh.gif

I unmounted it, took it out and checked the switch. It really was in the "Lock" position blink.gif But I just formatted it with the Zaurus mere seconds before, and it didn't complain then... dry.gif

So I decided to give it a try. I made sure the card was write-protected, put it in the Zaurus and ran this:
#touch /mnt/card/test

No errors came out.

I took the card again to my computer, without touching the switch, and sure enough, there was the "test" file. When I try to delete it with the computer, it complains again (as it should) that the card is write-protected.

Does the Zaurus just ignore the write-protection switch on SD cards? It's dangerous!
Write protect switch on SD cards need to be checked by driver - it is not mechanical like it was in 3.5" floppies. So maybe Sharp did not implemented it.
pdaXrom uses/used MMC drivers... MMC cards do not have write protect switches...

I see... So basically Zaurii have a MMC slot, only it's thick enough to fit SD cards.
Still, there should be a warning about that somewhere in the documentation... maybe it is, but I can't read japanese tongue.gif

Thanks for your replies, everyone.
The japanese doco would only apply to the Sharprom. You're running pdaXrom, which is an altogether different beastie. smile.gif

It /is/ an SD slot, however in order to support it in software you need to pay a ransom*cough*licensing fees (sorry) to extortionists*cough*patent holders (sorry again) which tends to put a bit of a damper on the free software spirit.

...good thing SD cards have to support the older (and more open) MMC interface, so we have MMC drivers. smile.gif

Does anyone *actually* rely on that write protect tab anyway? I wouldn't, and that's even if it didn't look like it would break off if I breathed on it too hard...
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