How to direct select an image

[AdmDecker]

SD Card HXC Rev. C

Hi, I'm working on an alternative way to select images without the need of pressing the up / down keys.
Well I figured the pins for selecting up and down at interface J2 having the same behaviour than pressing directly the keys.
I tested to pulse up and down by using an arduino uno.
Obviously it takes takes too much time for switching to the desired image, because a key press needs a high to low duration of about 170ms and needs a delay of about 170ms to pulse again.
Another way would be to communicate directly to the emulator via the floppy cable.
Does anyone know the method and the specific protocol for this communication? (I assume it's a serial RX/TX communication over 2 unused wires of the floopy cable)

Thanks.

[AdmDecker]

Okay, I browsed the forum and found some interesting topics to this.
Now, I think I understand the principle of how the communication works.

Is there a way to let an arduino select an image by communication over the floppy cable?
Does anyone has some experiences on this?

Thanks