SD card in an MMC slot (not the other way around)

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Kyosho
Portablizer
Posts: 338
Joined: Fri Jan 06, 2006 9:38 pm

SD card in an MMC slot (not the other way around)

Post by Kyosho »

Okay, so we all know MMC cards fit and work in most SD-reading devices and whatnot. But SD cards do not in MMC devices. The problem is that the SD card is a little bit too thick to fit, and also the contacts are not directly on the surface of the card, but slightly indented. Also, I've heard the SD cards have an extra contact on them that're used for data encryption. Which I think has to do with the "lock" switch on the SD cards. I could be wrong.

Now, as some of you know, I bought an N-Gage QD. I don't have an MMC card, and really have no use for one outside of the N-Gage itself. Plus they're expensive, and I can't seem to find any with a large capacity. I do have an SD card that may or may not be getting traded away though. Assuming I can get the SD card in the slot (with some difficulty I'm sure..maybe even some dremeling), do you think the N-Gage could read it properly?

I realize that most of you here probably have no idea. Because honestly it's kind of stupid. But this is really the only place I know of with people that would even attempt something like it. Because modifying is involved.
tom61
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Joined: Fri Mar 25, 2005 6:51 pm

Post by tom61 »

Never heard of SD cards not being able to fit in MMC slots, that's odd. It might be that Nokia wanted to make sure you use only there cards.

The tab is basically the same as a write-protect tab of a floppy (if you remember those), as in that it's a purely physical device to click a switch in the writing device itself. For 1GB and lower SD cards this is the only 'DRM' scheme I know of (2GB and greater cards have more advanced DRM). SD and MMC have the same number of pins, even though SD can use more lines to read/write faster

Most 1GB and lower SD cards will work in MMC devices. However, some 1GB and lower cards (I think Kingston is the brand) and nearly all 2GB+ SD cards lack MMC compatability and won't work.

It should be noted that there is an external adapter for the orginal N-GAGE to bring out the internal card slot. It might work with your QD to let you use physically larger cards.
bevo
Posts: 44
Joined: Sun Sep 24, 2006 5:17 am

Post by bevo »

SD cards will not work even if you manage to wire it up. The NGage software can only read MMC.
tom61
Senior Member
Posts: 1517
Joined: Fri Mar 25, 2005 6:51 pm

Post by tom61 »

bevo wrote:SD cards will not work even if you manage to wire it up. The NGage software can only read MMC.
Most =<1GB SD cards have a MMC compatablity mode, so, to the NGage it will be seen as a MMC.
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