DVI and sound no IO board

Discussion about displays and related hardware including MiSTer filters and video settings.
nizce
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DVI and sound no IO board

Unread post by nizce »

Hi!

If I where to connect my mister to a monitor with only DVI input, am I able to get sound somehow without the IO board?
I was thinking of getting a HDMI -> DVI converter which also has a 3.5mm headphonejack and toslink.

I thought I should work, but then I looked in the mister.ini file and saw a option called dvi_mode. The comment in the file states that sound is not supported if set to 1.
No other explanation what the dvi_mode actually does, but I can only guess it's _needed_ to get a DVI planel working(which would mean an IO board is required :()?
AngelicLiver
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Re: DVI and sound no IO board

Unread post by AngelicLiver »

If the converter extracts HDMI audio then it should be fine with "dvi_mode = 0". I'm pretty sure the purpose of dvi_mode is to just disable HDMI audio out as DVI does not have audio pins on the connector.

If you're potentially spending $20-30 you're probably just better off just getting an IO board...
Shamus
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Re: DVI and sound no IO board

Unread post by Shamus »

I use a couple resistors and caps to grab the audio signal from pins of GPIO1:

Phone_jack_out.jpg
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nizce
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Re: DVI and sound no IO board

Unread post by nizce »

Thanks!

Seems quite hard to get a IO board in Europe for a reasonable price(almost 70EUR with tax and shipping) right now.
I think I'll go with the converter/extractor or I'll take a chance and order one from an Amazon seller, they're cheap but you never quite know what you get :)
FoxbatStargazer
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Re: DVI and sound no IO board

Unread post by FoxbatStargazer »

*Passive* HDMI->DVI converters need DVI_mode=1. (They won't ever have audio breakout.) Most devices negotiate with the display to figure out that it can't accept audio, but Mister does not and needs that setting toggled.
nizce
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Re: DVI and sound no IO board

Unread post by nizce »

Thanks!
So a converter which includes ex. 3.5mm out should work with dvi_mode 0
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