What you're suggesting won't be possible with a standard cable because it doesn't carry the +5V pin. You could modify a link cable on both sides so it carries +5V power from one side to the other. Or you could use a standard link cable and provide power to the ArduinoBoy from somwhere else, liek a battery, say.

My idea is that I can use both, a standard cable link and a modded +5V one, so I can use it with a MIDI device with only GB, as well as with a computer just to MIDI-sync. Is that possible?
My arduinoboy is not ready yet, had so much work from college.

i dunno, i feel like having it powered off the dmg port increases the chances of your dmg crashing during a live set or recording. Plus ive had some weird noise issues with midi and the dmg audio that goes away when i unplug the aboy from the dmg.

Oh got ya. Yes that would work as well but what would be the advantage? Just build one that only has the male connector end of the cable and make the whole arduinoboy snap onto the side of the dmg. That'd be sweet.

I think he's talking about taking the link port connector from another dmg and puting it into standalone arduinoboy so you can unplug the cord.
That kind of arduinoboy should have it's own batteries imo.

So you're talking about soldering a few wires directly from the arduino onto the dmg pcb through the link port rather than using a link cable? Yes that would work.

This could very well work, but be sure you use a link cable that connects all the wires.
I believe the normal standard black link cable has some connections missing (like the +5 pin)

OK, I am still working on my Arduinoboy, but I think this should work fine. Sorry if this was posted before or something like that, or if this isn't even possible.
Basically, you just take off the external connection port from a DMG and sold shit like this, so you just put a link cable into the device and you're good to go.
You're still destroying a DMG, but I used one that wasn't workin' at all.