Are Micro cards with adaptors compatible with all mini slots?

This is something I need to research. In one case I noted someone saying that the device in question would not accept a micro card with adaptor into the mini slot!

Maybe there are more details which will scupper my idea.

One factor is whether you can physically remove the card from the adaptor after inserting it! (I have one of these, and don't fancy trying to remove it now I've inserted it).

The smaller the card inserted in the adaptor, the greater may be the risk of breaking it or the harder to grip it unless you have very small fingers.

Hmmm, another good point

OK, having gained some experience with micro cards in mini adaptors, I would now say "avoid micro cards like the plague if you can"

Yes, they are really small, and getting them into a mini adaptor may be easy, but getting them out again...arrgghhh, can be flipping tricky, and I just broke a mini adaptor by holding it on the edges to avoid squeezing it onto the micro card, and when the micro card came out the flipping adaptor snapped

So I would say, if you can get a standard size card, because they are nice to handle.
If you NEED a mini card, get a mini card.
If you NEED a micro card, well be careful !

As with all theories, they are tested, and prove good, or in this case, bad bad bad.

Well actually, if you are careful, and don't go breaking them, the MicroSD solution is still a good idea, as you can use the card in a micro device, or a mini device or a standard size device.
I think it's just not such a good idea to pick a solution which will involve repeated pulling out of the MicroSD card from the mini adaptor. From a standard size adaptor it should be a lot easier. Just avoid squeezing the sides together as you'll probably make it difficult to pull out the card, and don't squeeze the edges either as the adaptor is likely to break when you pull out the card. Try and hold the end of the adaptor just to stop it moving in the direction you're pulling on the card.

This theory isn't exactly busted, it works, a MicroSD card does work in a mini/standard size slot, but it may not be the friendliest solution if you have big fingers or are a bit clumsy

Wikipedia has a good page:

Comparison of memory cards
http://en.wikipedia.org/wiki/Comparison_of_memory_cards

Note that SD cards (not SDHC) only go up to 2GB. Some old cameras will only support the older SD standard, and will not work with the newer SDHC cards (I know from experience )

Unfortunately the compatibility chart is a bit vague on micro/mini compatibility.

But this page:

microSD Card
http://www.sdcard.org/developers/tech/microsd/

and this one:

microSDHC
http://www.sdcard.org/developers/tech/microsdhc/

say:

Hmmmm, interesting.

Note the pinning of each card:

SD/SDHC = 9 pins
miniSD/miniSDHC = 11 pins
microSD/microSDHC = 8 pins

Secure Digital Card, Pin Out
http://www.interfacebus.com/Secure_Digital_Card_Pinout.html

MiniSD Card description and Pin Out
http://www.interfacebus.com/MiniSD_Card_Description.html

microSD Card Description and Pin Out
http://www.interfacebus.com/MicroSD_Card_Pinout.html

    SD    MiniSD MicroSD
PIN Name  Name   Name
1   Data3 Data3  Data2
2   Cmd   Cmd    Data3
3   Gnd   Gnd    Cmd
4   VSS   VSS    VSS
5   Clk   Clk    Clk
6   Gnd   Gnd    Gnd
7   Data0 Data0  Data0
8   Data1 Data1  Data1
9   Data2 Data2
10        NC
11        NC

They all have:

Gnd, VSS, Clk, Cmd
Data0,1,2,3

Some have Gnd duplicated, and some have spare pins.
This shows how a simple adaptor which just connects the pins of the card to the right pins on the adaptor should allow all cards to work in all slots.

This guy has bought both adaptor types, and is happy:

http://www.camerahacker.com/Digital/MicroMiniSD_Adapter.shtml

but note how small and fragile the smaller card/adaptor is.

Even more interesting, he's taken them apart in this article:

http://www.camerahacker.com/Digital/Inside_miniSD_Adapter.shtml