It was suggested I come here after I asked this question on r/3dshacks. I'm trying to get my head around how the 3DS streams data to both screens. My end goal is to try and consolize my original 3DS with a TFP410 chip. It's just a fun experiment overall though, the 3DS I'm using is an old beat-up one I bought so don't worry about me damaging it.
To be clear I'm not trying to capture anything, just merely display the output of one or both screens on, for example, a TV. I'll post what I posted to Reddit, hopefully you can get the gist of what I'm asking://START
I'm trying to figure out the connection points to basically break out my 3DS's screen into a chip that will allow me to connect to an HDMI or DVI display. I spent a while looking around and on 3dbrew.org I found this helpful page: https://www.3dbrew.org/wiki/Video_Capture (click through to get a high-res image). My question is however, how does this work for two screens? Obviously the two 3DS screens are not just different resolutions but different ratios. I can understand that both screens are most likely using the same 24-bit RGB bus, but here there's only one set of HSYNC, VSYNC and CLK pins. Does the 3DS act like it just has one screen, and output both screens, one on top of the other? In that case, does that mean suddenly the HSYNC pulses get more frequent when it starts drawing the bottom screen? And how do the screens know how to display only the data that applies to them? Or is there another pin or some other signal that determines which screen it's currently outputting to?
What's more, I found this image of the ribbon cable for a capture card that employs other test points not mentioned on 3dbrew: http://3dscapture.com/install/08.jpg. Probably some of these will be to control the 3D functionality, but we have like, 9-12 extra points in total. Anyone have any idea what they're for?
By the way, here's an annotated version I made of the above image showing the extra test points: https://imgur.com/a/LTmmgwD
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Thanks for reading, honestly this is the first time I'm learning about raw video signals and DVI, but hopefully I can make a project out of this.