My Dreamcast internal HDMI mod

Here is my Dreamcast Internal HDMI mod.
I decided to go with a RGB Scart to hdmi adapter, I know VGA is better resolution, and I initially had a VGA to HDMI adapter installed, but I didn't enjoy how it didn't want to display some of my games. So for better compatability I changed to scart.
This is the one I used from Aliexpress.

This is the circuit I used, plus I added 220uF capacitors on the RGB lines.


I wired to the bottom of the board and routed the wires along the back and up the side.
My power wires are a bit long in this pic as I was still prototyping it.



Hers is the back with the HDMI connector cutout, and a resolution select button above the AV port.




Here it is connected and running Bangai-o. Good times.





This was an fairly easy modification, only took an hour or so, and am pleased with the result.

 

Nice mod. I'm guessing there isn't any bad lag using that adapter?

 

I haven't noticed any lag.

 

Just added a video of some Hydro Thunder with this adapter

 

My question will be does it scale to 720 or 1080p?

 

BEAUTIFUL WORK!

 

These Chinese scalers are all the same, have around 2.5-3 frames of lag. Cannot interpret 240p properly, and will display the DC in the incorrect aspect ratio.

If you want an internal mod, just hold off a little bit longer, DCHDMI is in fabrication right now.

 

Hehe
Good news indeed !

 

@Somechump: Is the HDMI chip near the HDMI output a "MacroSilicon MS9282" by chance?

 

It has multiple output resolution you can select, 1080P being the highest, but I found anything over 720P starts to make the image look darker and introduces a small amount of stutter.

 

I was curious about this comment and your statement of it not displaying 240p properly, so I ran the 240p test suite and everything looked good, including the aspect ratio.
How exactly does it not display properly?

 

Does it pass the drop shadow test? If the shadow is displayed as horizontal lines, then it means that it deinterlaces 240p which is wrong. The shadow should be solid and only shown every other frame.

 

I see. Thank you for the info.
Well I can't comment on the effectiveness of the scart to hdmi adapter, as my TV shows horizontal lines during the drop shadow test with both the AV output and the hdmi.

 

Then the SCART to HDMI scaler doesn’t properly support 240p, meaning that it sees it as 480i and adds deinterlacing, which causes these stripes.

 

There is no evidence that it is the adapter, as I said my tv has the same result when I use the av cable.

Anyway. I am happy with the result.

 

But it is the adapter.

The TV doesn't see 240p, it sees whatever the adapter is outputting (such as 1080p). The damage is already done. This happens over composite video direct to the TV because the scaler in your TV suffers from the same issue as the converter, just like many modern HDTVs and cheap converters.

A properly scaled image with a proper upscaler is always better than these cheap things. I have one of those converters and quite honestly, it is junk. The aspect ratio is stretched to 16:9 when it should be 4:3 with black pillars on the sides. Setting the TV to 4:3 helps but it still doesn't feel right to me.

This has been common knowledge for a few years thanks to rigorous testing by people in the community with the proper tools.

I highly recommend waiting for the HDMI mod as it will not suffer from any of this.

 

Yes there is. Had the SCART adapter worked properly with 240p, the drop shadow would look correct on your tv, as the tv would be getting a 720p image through HDMI. A modern tv would never deinterlace a 720p signal.

That you get the same issue on your tv using an av cable just tells us that the tv doesn't properly support 240p either.

Edit: MonkeyBoyJoey was faster