DC SD Card Adaptor

DC Emu forum thread to register interest.
Original Spanish article.

 

Any help in finding lots of dc versus link cables would help much, and if they are cheap it will reduce the cable price a lot. Pm me if you have a lot of these or know where to get they cheap....

This is all based on jjd01m's work a lib has already been made to use it easily with homebrew and will be released soon.

 

I'd be happy with just getting my hands on the PCB so I could do an internal mod. I could solder directly to the serial port pins on the DC motherboard.

 

There's no pcb needed. All you need is the actual slot receptical, a resistor and two capacitors (just for help with grounding).

 

nice find where do i get one from

 

cool thing, beats my BBA-NAS idea. (less space, but far less expensive)

 

Dodgy Google translation of jj1odm's Japanese web page. Everything you need to know about doing wonderful things with a DC Serial port.

jj1odm's original, untranslated web page.

 

ELF LOADER RELEASED !

http://f17.aaa.livedoor.jp/~takotako/dcserial_ft232bm.php#dcsdload

FamilyGuy

 

WOOOT! How can I buy this shit dude??
Edit: Good to see ya around FG. I need to talk to you about some mods

 

mmmm this probally means that if you get the SD loader to run on a devkit, you can REALLY EASY rip GD-R's!

 

where can you buy this thing anyway?is it going to be sold in limited amounts by 1st come 1st serve or what?

 

Id like to buy one of these cables too :nod:

Im also interested in adding an SD slot internally inside my Dreamcast as Quzar said:-

I looked at jj1odm's schematic but noticed there is also a diode (1N4148?) with a small arrow, but im not sure what thats connected to?

Also, the pre-made SD cable appears to be a combination of a versus cable and a USB SDHC card reader like this one from eBay:-
http://cgi.ebay.co.uk/SDHC-SD-USB-2-0-Memory-Card-Reader-for-2GB-4GB-8GB-16GB_W0QQitemZ260377314284

Now what im wondering is if all the neccessary components are already inside that card reader and its just a matter of 'connecting the dots', or are extra components still needed aswell?

Also, does the jj1odm's original circuit already support SDHC, or is that only possible when using a modified USB SDHC card reader like the one I linked to above?

I hope no one minds me asking, and thanks in advance :icon_bigg

<EDIT> Is it definitely just a resistor, 2 x capacitors, and a diode? I only ask as looking at jj1odm's site I notice the picture below the schematic shows a chip being used?

 

The pre-made cable is really a hybrid between a versus-cable and a usb sdcard reader.

To make it yourself, you'd have to remove the USB part of the USB sd reader, this mean the usb connector and chips. Then it'd be pretty straightforward, I guess the diode is connected the same way as in jj1odm schematic as it should be generic. You might have to add the caps to the USB dongle.

JJ1ODM made an internal mod that's pretty cool IMO to his DC. My own cable is really ugly and consist of a breadboard with a sd-slot and 9-pin serial cable hanging out + Opened DC with other end of serial cable hanging out ... But it works really well!!!

The diode is connected just like in the diagram, follow the traces and you'll get where to connect it. Note that a lined triangle mean GROUND.

SDHC support is solely software-side ; so the cable could in theory handle it with not problem as long as a lib or driver for sdhc (FAT32) is made. AFAIK 4gig SDHC cards DO work with this cable as long as they are formatted to FAT16.

FG

 

Thanks for the help :nod:

I think I may have misunderstood the schematic :redface: I now think its a symbol for an LED(?) not a diode. Its not quite like any symbol I have seen for an LED before so thought it was a diode (You have to admit they are pretty similar symbols!)

So I guess if am not interested in adding an LED I should be able to leave out the resistor and the LED? In which case that circuit is incredibly simple :icon_bigg

Still curious why the photo below the schematic shows a chip being used though...

hmmm....Thinking about this some more, couldnt we do this in reverse? eg connect up the Dreamcast serial port to the USB SD card readers SD port, then we would have a simple Dreamcast<->USB connection?! Perhaps wishful thinking...

 

LED = Light-Emitting Diode

 

:lol: Yeah thanks, its just I knew the symbol was for a 'diode' but didnt understand what the small single zig-zag arrow was for. I have seen LED symbols before but usually they have two straight arrows. Perhaps its a Japanese specific LED symbol? (I believe the Japanese Capacitor symbol is different)

 

Yeah you can forget about the led if you want.

about the chip on a photo, read cartefully ( and translate) and you'll find out it was an old design that was really slower because of the chip timing and delay.

Foget about the reverse usb thing, I don't think it's that simple DC serail is 3v that 's why it's so easy to hack a sd-card reader into it, as sd cards are also 3v. USB is 5v and is a bit more complex than sd-card 'cause it's designed to do any thing you want to, usign the right drivers/hardware.

FG

 

We can use 5v directly from the power supply

 

so homebrew could be rewritten to used the new DC "harddisk"? that might spur out interesting linux news too

 

No, since the serial port itself runs at 3v. look for the serial => USB cable schematic online and you'll see a how complex they are just to conver the voltage.

FG