What features do you want in a DexDrive replacement device?

[Thutmose]

Re: What features do you want in a DexDrive replacement device?

USB, easy file transfer

Yeah, I'm already planning on making it USB.

KUPID compatibility (lol, jk).

Well, it would be possible to put everything in one case, and it would save the customer money if they are going to buy both Kupid & this DexDrive replacement (DDR as a temp name until I figure out a better one).

Since Kupid 2.0 will likely be using an Atmel AVR MCU, and so will the DDR, it would be cheaper to put everything into one case using one MCU rather than having two separate cases, with two separate MCUs, etc. Building it as a single unit would mean that the overall price would be reduced by $20-30 over buying both separately.

So, maybe I could offer three things:

• Kupid 2.0 - $35
• DDR - $60 (estimated)
• Kupid 2.0 Ultimate with Built-In DDR - $65-75 (estimated)

[orius]

Re: What features do you want in a DexDrive replacement device?

I wonder if it would be feasable or even possible to make a device that can handle saves from both PS1 and PS2 cards.

[Thutmose]

Re: What features do you want in a DexDrive replacement device?

I wonder if it would be feasable or even possible to make a device that can handle saves from both PS1 and PS2 cards.

I don't see why not. I haven't done any research on PS2 memory cards, but they surely work on the same principal and same general SPI protocol as the PS1 cards, just with larger memory and probably different file structure.

I'll see what I can find. Maybe I can add a PS2 card-reader function too.

[Valkysas]

Re: What features do you want in a DexDrive replacement device?

the max drive, which is the main file transfer device used, compresses all the files during conversion. so that may be a bit difficult to work with.

also, the max drive itself is rare as **** now.

[Thutmose]

Re: What features do you want in a DexDrive replacement device?

the max drive, which is the main file transfer device used, compresses all the files during conversion. so that may be a bit difficult to work with.

also, the max drive itself is rare as **** now.

Yeah, I have one... somewhere. :P

I'm pretty sure there are converter programs out there that can convert a MAX file into a raw memory card file or other formats.

Basically it doesn't matter what device was originally used to get the save off of the memory card, if that save can be converted into an uncompressed file, then it would be possible to write the data to a memory card with a custom built device. This applies to both PS1 & PS2 memory cards & saves.

[Valkysas]

Re: What features do you want in a DexDrive replacement device?

yeah, we have one of the converter programs here here in our tools section..

just thought that with the compression, that might make it hard to handle in a hardware-only solution.

[Thutmose]

Re: What features do you want in a DexDrive replacement device?

yeah, we have one of the converter programs here here in our tools section..

just thought that with the compression, that might make it hard to handle in a hardware-only solution.

If it's possible to do in software on a computer, then it's possible to do in hardware/firmware/software in an embedded device.

Either people can use a program to decompress/convert the Max saves before putting it on the DDR, or I could build that functionality in (depnding on whether or not I can find or figure out the compression algorithm used).

[Thutmose]

Re: What features do you want in a DexDrive replacement device?

My work on Kupid 2.0 has taught me a lot about the PlayStation SPI protocol, and some of the code I've written for K2 is applicable to DDR.

My breakthrough last night has made me a lot more optimistic that developing a DDR is feasible. Once I directly observe (using my logic analyzer) the reading & writing of a PS1 memory card, then I would be able to figure out the specific command bytes that need to be sent, and what their functions are.

After I get the design of K2 finalized, I can start doing some experiments with PS1 memory cards.

[orius]

Re: What features do you want in a DexDrive replacement device?

I don't see why not. I haven't done any research on PS2 memory cards, but they surely work on the same principal and same general SPI protocol as the PS1 cards, just with larger memory and probably different file structure.

I'll see what I can find. Maybe I can add a PS2 card-reader function too.

My thoughts are that the MagicGate stuff on the PS2 cards might make it more difficult or something. I'm just speculating, I don't really have any clue as to how they work. A combined device, if doable, though could possibly have greater demand than a device just supporting the PS1.

[ErikaFuzzbottom]

Re: What features do you want in a DexDrive replacement device?

I'd imagine finding and assembling the parts that the memory cards would actually plug into would be a bit tricky.

[Thutmose]

Re: What features do you want in a DexDrive replacement device?

I'd imagine finding and assembling the parts that the memory cards would actually plug into would be a bit tricky.

From what I've read, the old ISA bus connectors will connect properly to a PS1 memory card (when cut to size). I could probably get a bunch off of ebay or someplace.

But I need to do some more research to figure out exactly what's required. Hopefully it won't be too much of a stumbling block.

My thoughts are that the MagicGate stuff on the PS2 cards might make it more difficult or something. I'm just speculating, I don't really have any clue as to how they work. A combined device, if doable, though could possibly have greater demand than a device just supporting the PS1.

It's possible that PS2 memory cards will be rather difficult to interface with. I've never actually read anything about doing that before, so it may not be possible. Time will tell.

[Zeroth]

Re: What features do you want in a DexDrive replacement device?

Man, I gotta say that what you are doing is amazing. If only you could've done this six to ten years ago. You'd have some serious cash by now if you did.

[Thutmose]

Re: What features do you want in a DexDrive replacement device?

Man, I gotta say that what you are doing is amazing. If only you could've done this six to ten years ago. You'd have some serious cash by now if you did.

Thanks.

10 years ago I was 11. If I were able to do all this then, I probably would have been able to get into a good college, and had the money to afford it; at the very least. But, you know, the public school I went to back then didn't offer embedded electronics design classes (not like electronics are all that important in this day and age). Instead, I had to take drama, as there were no other elective courses offered. Yeah. Time and tax dollars well spent.

Now that I have a job (two shortly) I can afford to give myself the education that I and millions of other students in the US got cheated out of.

Vocational education is now a dirty word. Heaven forbid we teach students skills that are actually practical and might help them secure jobs or undertake entrepreneurial ventures in the future. More worksheets and literary analysis for all.

But at least I learned to project when on stage. >_>

/sarcasm /rant

[Thutmose]

Re: What features do you want in a DexDrive replacement device?

My thoughts are that the MagicGate stuff on the PS2 cards might make it more difficult or something.

I've done a bit more research. MagicGate encryption may pose a significant problem - but, it has been cracked/circumvented before (though, by people far more technically skilled, knowledgeable, experienced, better funded, and equipped than myself).

So, I know it is technically possible to create a device that can act like a DexDrive for PS2 memory cards, but I don't know if it is possible for me to do in any less than a decade of research and learning.

There doesn't seem to be any material available that goes into detail about this. Which is understandable since anyone who has ever been able to crack/circumvent MaicGate has done so for commercial gain and wouldn't want the secret to be leaked. But if anybody can actually find something and point me to it, that would be great - searching and reading through thousands of Google search results takes way too much time for me to see everything.

But, I know that PS2 memory cards still operate using the same pin assignments as the PS1, and thus would be using the same basic SPI protocol (probably with different command & data bytes), and that at least gives me somethign to go off of. Again, I haven't been able to find much info on PS2 cards. No doubt because of the problems with MagicGate encryption/protection.

Once I manage to get the PS1 memory card stuff working, presuming that I am able to, I'll start working on PS2 memory cards. I'll need to buy a cheap PS2 off of ebay so I can tear it apart and use my logic analyzer on different traces & chips to see if I can figure out how it works (maybe buy a couple 'cause I'm sure I'll brick at least one or two :P).

This may also give me an opportunity to read up on encryption cracking, reverse engineering, and perhaps GPGPU supercomputing for encryption analysis & cracking (my comp is capable of over 3 teraflops using CUDA). More books to buy! ^_^

So.... lots of research and work to do for the PS2 memory card component. If I can do it, well, it certainly would be an accomplishment. But I doubt very much that it will be feasible for me to do in any reasonable period of time.

The PS1 DDR, though, shouldn't pose too much of a problem as best as I can tell right now. There isn't any encryption or special copy-protection, and the memory format is fairly straight-forward. It's largely just a matter of reverse engineering the communications protocol by observing read/write cycles with a card plugged into a DexDrive (I have one DD, but I'll have to tear it apart to analyze it... it would be nice if I had at least one more in case something goes wrong), emulating the host behavior in software based on my observations, and designing the final circuit. Maybe a few other steps here and there. But relatively simple. Ideally.

[Thutmose]

Re: What features do you want in a DexDrive replacement device?

I've read a bit more about PS2 memory cards, and MagicGate in particular. As far as I've been able to tell, MagicGate has only potentially been cracked by Datel Design & Development Ltd who created a special chip (called "GateCrasher") which allowed the company to produce unauthorized PS2 memory cards in larger capacities than what official Sony memory cards supported.

While not truly cracking the the encryption, the GateCrasher chip worked by faking a correct response to the MagicGate challenge-handshake authentication protocol, making the host PS2 think that the unofficial memory card supported MagicGate when it really didn't. This allowed the card to be used by the system without actually encrypting/decrypting the data transferred to/from the card. Basically it bypassed the MagicGate protection.

So it is possible to circumvent MagicGate, though certainly it's not easy. But, from what I've read, the host device decides whether or not to use MG. If the host doesn't initiate the MG challenge-handshake authentication protocol, then the host can access the memory card freely. Encrypted data is still encrypted, though.

But, in theory, if I can create a host device that can read all the data directly off the memory card, without initiating the MG functionality of the card, then entirely duplicate the card's data onto another one, then MG shouldn't pose any kind of problem. Unless the encryption key is based on a built-in device/hardware serial number. In which case, although it would be possible to duplicate the flash memory portion of the card, the data could not be decrypted as it would have been originally encrypted using a different hardware serial number. I don't imagine that's the case. It will require experimentation to find out, though.

Still lots more research and testing to do. I don't think that it will pan out - MagicGate makes dealing with PS2 memory cards too difficult. If it were easy, then there would be a simple DexDrive-like device for PS2 already on the market (there have been other devices, but they required special software to be loaded onto the system. More recently there has been the http://www.memor32.com/ device which looks pretty cool).

I have more books on the way, too. Naturally.

This is a picture of one of my official Sony memory cards with the two chips labeled: http://rpgmakerxp.us/assets/memory_card_circuit_med.jpg

I'll just be focusing on the PS1 DDR after Kupid 2.0. And maybe do a few experiments with PS2 cards after that, but I don't expect the PS2 functionality to ever really work.