aliexpress, are you ok? and if this is actually a thing, who tf has digital vga!?

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I think this works the other way around 🙂 HDMI can additionally carry an analog signal.

@fribbledom nope, it's advertised vga->hdmi. also hdmi doesn't do any analog either afaik. the only thing that worked painlessly was dvi->hdmi because dvi supports analog and digital. well, strictly.. DVI-D is HDMI, just without some of the between-frame signalling HDMI permits while vblank happens in the video signal


Interesting, I have been using passive HDMI->VGA cables on various systems (>10 years ago).

So much misinformation out there, which also breaks with another thing I've been taught years ago: DVI and HDMI carry the exact same signal and feature the same 29 pins, just in a different form-factor. Apparently not true?

I'm confused now 😆

@fribbledom yep, that's not true. dvi has lots more pins ( and hdmi also has features like an audio return channel or ethernet over hdmi (

the pinouts are really nice on wikipedia :3 also i never knew just how many dvi variants there were!


Interesting, apparently the 29-pin HDMI would have been HDMI Type B, which never made it to the market.

Another oddity: Wikipedia claims DVI can't carry audio signals, but my old 27" DVI monitor here does exactly that as we speak 🤔


Oh my:

"Although DVI was not designed for audio, some graphics card manufacturers created a way to bypass the restrictions, so they can carry over video and audio signals. We’ll run through the exact steps needed to carry over DVI audio in the next section."

@fribbledom @ln I like this quote a few paragraphs in: "The first two versions (DVI-I and DVI-A) use analog signals, which most modern GPUS are not compatible with"

Considering that DVI stands for Digital Visual Interface, I have to wonder what analog signals are doing there in the first place. 🤔

@ln I wonder if you could use the SERDES as a DAC like a Delta Sigma modulator.

@uint8_t @ln Hm, though that already uses a DAC chip instead of using a SERDES to make low-frequency analog signals... It won't work on a usual device, you'd need an FPGA for that, but then it should be possible to make a HDMI / VGA combo port by using the HDMI signals as analog signals. If you have 5 GS/s at 1 bit, you could get like I think 100 MHz at 6 bits?

@x44203 yeah it should work in theory with a low pass filter

@x44203 hmm, maybe? there's lots of really cheap ways to produce vga output.

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