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Karel Jansens's Avatar
Posts: 3,220 | Thanked: 326 times | Joined on Oct 2005 @ "Almost there!" (Monte Christo, Count of)
#11
Originally Posted by fanoush View Post
yes with default kernel, no with custom one and mounting by hand. But it will not work with SD card as it is thicker then MMC and won't fit. Works with 4GB MMCplus card though. could work with SD one in theory if you could made the card thinner somehow
Gentlemen, whip your Dremels out. (Hey! who messed up all the smileys!?)
 
Posts: 14 | Thanked: 0 times | Joined on Jun 2007
#12
what is a 4GB MMCplus card is it the same size as a RS-MMC, if so why am i messing with a 2gb card then
 
Posts: 58 | Thanked: 2 times | Joined on Jun 2007
#13
Originally Posted by Nrmf View Post
what is a 4GB MMCplus card is it the same size as a RS-MMC, if so why am i messing with a 2gb card then
RS-MMC and MMCmobile are both roughly half the size of MMC and MMCplus. The extra metal parts you see are just mechanical adapters.
 
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#14
Although I can't seem to find a microSD to RS-MMC adapter readily available, after lots of searching, I've learned the following things:

1. All SD cards (including microSD and miniSD) are required to be backwards compatible to the original MMC protocol.

2. The dimensions (Width x Height x Thickness) of an RS-MMC/MMCMobile card are 24mm x 18mm x 1.4mm.

3. The dimensions of a microSD card are 11mm x 15mm x 1mm.

4. Noting #1-3 above, it is feasible that a microSD to RS-MMC adapter device could be made. MiniSD is too long and thick to be used. (20mm x 21.5mm x 1.4mm)

5. Any card above 2gb would require kernel modifications to accommodate the increase in size. Similar modifications have been performed on other embedded platforms that were limited to using MMC mode with SD cards (OpenWRT-compatible devices for example).

Anyhow, heres hoping my findings can be the start of getting a 4+gb flash card for the 770.
 
Posts: 2,152 | Thanked: 1,490 times | Joined on Jan 2006 @ Czech Republic
#15
Originally Posted by elph View Post
1. All SD cards (including microSD and miniSD) are required to be backwards compatible to the original MMC protocol.
No. SD cards do not support MMC mode. Both MMC and SD has common ancestor which is SPI. And Wikipedia says "All memory cards must support all three modes, except for microSD where SPI is optional." http://en.wikipedia.org/wiki/Secure_Digital_card

But anyway this does not matter since SD mode has 1 bit mode too so it can in theory run in MMC slot in N770 (6 wires) in SD mode so SPI mode support is not needed.

N770 kernel has even optional support for 4 bit mode (if bootloader tells it that the device can do it) so maybe there are newer N770 devices in the wild which do support 4 bit mode i.e. have all pins in the connector which are needed for faster 4bit SD (and MMC) mode. My N770 (november 2005) has only 6 metal pads in the slot so it definitely can't do 4 bit mode.

Can anyone with really new N770 device say if you have more metal pads in the slot (8 or 9)? It may be that such device did not ship at all, there are other things in kernel targeted for devices that never shipped so this wouldn't be surprising.
 
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#16
6 pads on my new one from woot deal.
 
Posts: 58 | Thanked: 2 times | Joined on Jun 2007
#17
fanoush-

I count 8 pins in mine (from the woot sale) There are two pairs that are very close to one another and the rest are evenly spaced- i'll try and draw a little diagram.

From the end of the unit to the middle this is their layout (screen facing down)

|_|_|_||_||_| headphones USB pwr

Hope this helps.
 
Posts: 2,152 | Thanked: 1,490 times | Joined on Jan 2006 @ Czech Republic
#18
Thanks robbh66, are you sure there are metal plates in all 8 or 9 positions? Can you post /proc/component_version (hw-build)? Also photo would be nice :-) And then (if you really have more pins) speed test with some fast mmcmobile card (kingston 2GB) would be interesting
Code:
time dd if=/dev/mmcblk0 of=/dev/null bs=8192 count=10240
both with default kernel and with mmcplus enhanced one.
 
Posts: 17 | Thanked: 0 times | Joined on Jul 2007
#19
a micro SD adaptor would be so cool since my 8525 and my Slvr L7 both use them and I got like 3 laying around, imaging if there was an adaptor to plug in two micro sd cards into a rs mmc adaptor. that way you could have one card for just booting and one to hold movies or music

Dreaming is nice
 
Posts: 6 | Thanked: 0 times | Joined on Jul 2007 @ Arizona
#20
I'm a newbie 770'er.
Looks like ELPH was about right.

RS-MMC and MMC Mobile are compatible. MMC Mobile appears to be faster.
Any 770 user should check this out.......

http://www.newegg.com/Product/Produc...82E16820134119

Check user reviews.

Mine's coming Friday! ;-)

Newbie question.......
What's the easiest way to access the finger keyboard?
 
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