6 replies to this topic

[predator363]

I see card adapters everywhere. micro SD to SD, Micro SD to MSPD. my main interest is SD or MSPD to CF converters. Why do we not see the opposite? I can go on line right now and order the parts i would need to make a device that could take 4 standard SD cards and read them as one super fast, massive SD card. How much of this is hardware and how much software? i would be very interested in any projects ongoing about this too. If you can for instance have a MSPD to CF adapter. other than size and shape what is to keep the reverse from happening? Also if you can have an adapter that can convert two micro SD cards in to one large MSPD could you do the same with 2xCF=1xMSPD? and so on and so fourth? Could i say build a tray capable of holding 50 CF cards and have a computer recognize it as a large ESata drive? Or even a SD/SDHC card reader that still read each card individually but was capable of holding something like 10-100 of them. I would absolutely love to build devices like this. Call me weird but i have a passion for wanting to do as much/many things as possible with small portable media. I may have not done a very good job with this post, so please ask questions as well i will elaborate.

[gregwarner]

SD to CF adapter:
Amazon.com: SD-CF II: SD to CF Type II Adapter (Supports SDHC MMC): Electronics

As for multi-SD card arrays, here's a forum thread talking about why that's unnecessary: (In short, because unlike hard drives with seek times, Flash memory is already many magnitudes faster due to instantaneous seek times. If you're looking strictly for storage size, it's because of the cost-factor. Hard drives are much cheaper for building a mass storage array.)
Why no SD Card RAID? - Tech Support Forums - TechIMO.com

[predator363]

Hey thank you very much for the attention to the thread. You kind of seem to have not read/understand what i said. I have my own personal reasons for the SD or CF array, also i stated pretty clearly that i already knew where to get things like SD to CF adapters. Again im extremly thankful for the attention im just wanting to focus more on the things you dont see.....not the things that are openly available in every corner of the web.

[gregwarner]

If you're wanting to build a flash storage array, you could get several CF to SATA adapters like in the link below and just use a software RAID 0. I'm sure there are tons of resources available on the web showing how to build a software RAID.

CF - SATA HDD Adapter from Addonics

As for MSPD, it's kind of a proprietary format for Sony devices, which is why you don't see a lot of support for them in any application other than Sony's products. The licensing fees paid to Sony by 3rd party developers would negate the usefulness of the format.

[predator363]

ooooohh thank you thank you thank you! I hadn't quite thought of the licensing thing! Do you believe building such devices are complicated? and would you consider it to be more of a hardware task or software? I have at task right now the need to build two separate devices. one being a tray which can hold upwards of 50 flash devices of all the same type. the second being a device that would take CF or SD or even just multiple MSPD's and make the device they are plugged in to read it as a single MSPD. i would absolutely love to do something like zif>MSPD but i dont know that its possible.

[gregwarner]

As far as getting several devices to read as one, it could be hardware or software. First, you're going to need to physically connect all these devices together (hardware). Secondly, you're gonna have to get them all talking to each other (software).

It would be simplest to use Flash to SATA adapters and treat them as one big RAID drive on a computer. However, if you want to use them in an electronic device, such as a camera, as far as I know, there's no way to get multiple CF or SD cards to natively work together in a cluster configuration-- their interface protocols simply do not have the capability for this. So if you want to be able to use multiple cards as a single card, you're going to have to build yourself a header in the shape of the card to connect the card reader slot in the device via a dongle to your cluster circuitry. Next, you're going to have to emulate the CF or SD protocol to the device it's plugged into, so the device thinks it's talking to a memory card when in fact it is talking to your emulator.

I've never done anything like this before, but I would assume you could perform the emulation with an Arduino or other similar embedded microprocessor or microcontroller. The microprocessor would read and write the CF or SD instructions from and to the device, and on the other side, it would actually store the data in whatever configuration you decide. You can write directly to the filesystems on the physical cards, filling them up one by one, or you could write each block to each card in sequence, for a striping effect. I don't know that you're going to get any speed boost by doing this because remember you are limited by the bottleneck of the single card interface going into the device. You may also end up having to invent your own filesystem to store the data on the cards in any retrievable manner.

Also, keep in mind the size constraints on the various flash memory protocols. CF cards made before CF+ Rev 5 in 2010 would be limited to 128 GB, I believe, and the SD protocol was limited to 2 GB of addressable storage, SDHC up to 32 GB, and SDXC up to 2 TB. You won't be able to emulate any higher capacities to a device that only supports a certain protocol, so plugging more than 32 GB of cards into a device that can only support SDHC would be pointless.

Seems you're going an awful long way to try to cram quite a bit of storage into a device. May I ask what kind of a device you plan on running off of this thing?

EDIT:

predator363 said:

Do you believe building such devices are complicated?

In a word, yes.

[predator363]

well its not necessarily for a single device. what i would like to build is a kind of universal translator for flash cards. The inspiration for the multiplier thing is from this Amazon.com: PhotoFast CR-5400 MicroSD to MS Pro Duo Adapter Dual Slot: Electronics i was given one of these a few years back and as cheaply made as it is it works wonders. when MSPD's were 80 for a 2GB i was able to have two 2GB SDHC for half the price and shove em in there. i have a LOT of MSPD devices and absolutely hate the format. I don't see any reason for such a slow format to be so expensive. So using affordable media as a substitute for expensive media can be a big factor here.