VGA Output VS Direct Video for Analog Video

Discussion about displays and related hardware including MiSTer filters and video settings.
retrorepair
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VGA Output VS Direct Video for Analog Video

Unread post by retrorepair »

I have a couple of questions about this.

First of all, is the difference between 18bit and 24bit all that noticable? I can't imagine it is, though for the sake of accuracy, 24bit sounds appealing.

I also notice there is now a Digital I/O board that frees up GPIO1. Does this mean the "analog" I/O board will eventually not be supported?
akeley
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Re: VGA Output VS Direct Video for Analog Video

Unread post by akeley »

I'm interested in the pros and cons myself, since I only display on CRTs. I'm just putting my system together and decided to skip the I/O since DV is cheaper. Is it on par with I/O, when it comes to 1:1 video output from all the platforms? Which ones are not supported atm?
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Sigismond0
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Re: VGA Output VS Direct Video for Analog Video

Unread post by Sigismond0 »

Unfortunately, it looks like that's not readily documented. The wiki states the following:
Direct Video is compatible with most current cores and will be supported in all future cores coming to MiSTer.
https://github.com/MiSTer-devel/Main_Mi ... rect-Video

The link just below that to analog video support by core does not specify which ones do/do not support it.

When it was first released, there was talk about how board freeing up another GPIO allows a second slot for RAM or some other accessory, but there's nothing on the immediate horizon that will require it. There may come a day when something like an N64 core or Saturn core requires a second GPIO to run, but I haven't seen any discussions about deprecating the standard IO board.

As for color depth, that's going to be one of those things that's just going to vary from person to person. There's no doubt that full color depth is objectively better, but how much any given person will notice or care will vary wildly.
mathieulh
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Re: VGA Output VS Direct Video for Analog Video

Unread post by mathieulh »

The Analog output on the IO board has some hardware issue which causes lower gain (and thus a dimmer picture), it is not that noticeable (other than on a direct compare) on a SD CRT, but it is very noticeable on a PC CRT or HD CRT.

I opened an issue about this here: https://github.com/MiSTer-devel/Hardwar ... /issues/11

Because of it I would rather advise to use Direct Video which does not suffer from the issue.
Bahn Yuki
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Re: VGA Output VS Direct Video for Analog Video

Unread post by Bahn Yuki »

mathieulh wrote: Thu Jun 04, 2020 5:04 pm The Analog output on the IO board has some hardware issue which causes lower gain (and thus a dimmer picture), it is not that noticeable (other than on a direct compare) on a SD CRT, but it is very noticeable on a PC CRT or HD CRT.

I opened an issue about this here: https://github.com/MiSTer-devel/Hardwar ... /issues/11

Because of it I would rather advise to use Direct Video which does not suffer from the issue.
I've found to be the case as well. I've made a video showcasing this : https://youtu.be/vIwj50l1ZjA
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