shmups.system11.org

Shmups Forum
 
* FAQ    * Search
 * Register  * Login 
It is currently Sun Feb 17, 2019 3:13 am View unanswered posts
View active topics



Post new topic Reply to topic  [ 6635 posts ]  Go to page Previous  1 ... 218, 219, 220, 221, 222
Author Message
 Post subject: Re: Questions that do not deserve a thread
PostPosted: Sun Feb 10, 2019 1:51 am 


User avatar

Joined: 20 Jul 2017
Posts: 350
I can't think of a good reason to use s-video cables for that purpose? It is completely non-standard - meaning it will be confusing as no device with an s-video port would work. I don't know that commonly available s-video cables are particularly well-made? Even the well made ones would presumably use the ground pins for coax.. which wouldn't work in this setup that I guess would need ground on the outer ring as all the pins are being used. I can't think of any advantage of using s-video over, say, VGA which at least has pins for RGB and sync already, as well as normally being well shielded, spare pins for stuff like vcc or audio. Alternatively just picking another common connector at random such as mini din 8 would provide a lot more flexibility, and that already has a somewhat standard RGB pinout anyway.

There are the 7 pin "s-video" connectors.. which could conceivably be used, but I am not sure what advantage they afford.


Top
 Offline Profile  
 
 Post subject: Re: Questions that do not deserve a thread
PostPosted: Sun Feb 10, 2019 2:07 am 


User avatar

Joined: 05 Mar 2018
Posts: 470
headlesshobbs wrote:
Awesome! Leo Bodnar has some actual competition now and maybe they'll have the incentive to improve their product line now.

OK question:

I've been wondering for the longest time why s-video cables have not been used to carry RGB signals instead when there's enough pins to support independent color lines, including one for H/V sync. This has been my "Elephant in the room" issue for awhile now.

But there's not though...

Luma + Luma ground
Chroma + Chroma ground

There's your 4 pins


Top
 Offline Profile  
 
 Post subject: Re: Questions that do not deserve a thread
PostPosted: Sun Feb 10, 2019 2:23 am 



Joined: 03 Mar 2005
Posts: 331
RGB needs five lines: red, green, blue, sync, and ground.

It would be possible to use an S-video connector for this IF the outer connector-shield were kept separate as its own line. However, on top of all the cheap cables that don't even connect this to anything at all, there are probably others that connect it internally to the ground pins for luma and chroma.

On top of that, decent S-video cables will run the luma/chroma ground lines as shielding over the luma/chroma active lines. If you put another signal on these, the cables would have AC coupling interference like crazy and would also not be proper 75-ohm impedance.


Top
 Online Profile  
 
 Post subject: Re: Questions that do not deserve a thread
PostPosted: Sun Feb 10, 2019 3:21 am 



Joined: 19 Jul 2017
Posts: 978
headlesshobbs wrote:
Awesome! Leo Bodnar has some actual competition now and maybe they'll have the incentive to improve their product line now.

OK question:

I've been wondering for the longest time why s-video cables have not been used to carry RGB signals instead when there's enough pins to support independent color lines, including one for H/V sync. This has been my "Elephant in the room" issue for awhile now.

It's a good question why the 4-pin DIN connector wasn't used for RGB to begin with; however, I imagine it wasn't used for both YC and RGBS because it would've caused customer confusion with people trying to feed RGB into a device that only supported YC, or YC into an RGB-only device.

Also, wouldn't it be best to have both positive and negative leads for each signal, rather than have a common ground?


Top
 Offline Profile  
 
 Post subject: Re: Questions that do not deserve a thread
PostPosted: Sun Feb 10, 2019 1:48 pm 


User avatar

Joined: 12 Aug 2017
Posts: 352
Location: Europistan
Are any of the Neo Geo multicards electrically sound or all they all plagued by 3V3 vs 5V Level translation issues?


Top
 Offline Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6635 posts ]  Go to page Previous  1 ... 218, 219, 220, 221, 222

All times are UTC


Who is online

Users browsing this forum: Dochartaigh, GeneraLight, Lawfer, SamIAm and 8 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
Space Pilot 3K template by Jakob Persson
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group