Build Your Own Arcade Controls Forum

Software Support => GroovyMAME => Topic started by: Foxhole on August 22, 2019, 03:02:32 pm

Title: A note about composite sync and post hd5000 cards.
Post by: Foxhole on August 22, 2019, 03:02:32 pm
I just wanted to share an issue i had with trying to get composite sync working, which i did manage to fix.
The operating system is windows 7 pro, the gpu is hd 7850, connected using a vga to scart cable i made.
On the crtemudriver page it says that for pre-HD5000 cards you need to set the polarity to positive and for post HD5000 cards nothing is needed.
My card is an HD7850. Turning on composite sync resulted in a black wobbly picture.
Long story short, you have to set the polarity in the monitor.ini to positive, by changing the 0, 0 to 1, 1,
And only then turn on emulate edid.
I did not find this info, so i thought it would be helpful to let you know.
FYI, if you turn on composite mode you may need to remove the vsync line from your vga/scart cable.
Title: Re: A note about composite sync and post hd5000 cards.
Post by: Calamity on August 23, 2019, 04:45:04 am
Thanks for posting this.

Actually, once you install modelines after enabling EDID emulation, composite sync will work correctly without needing to force positive polarities. But yes, if you only enable EDID emulation it won't sync automatically, I should add this information to the guide.
Title: Re: A note about composite sync and post hd5000 cards.
Post by: Foxhole on August 24, 2019, 01:20:42 am
Quote from: Calamity on August 23, 2019, 04:45:04 am
Thanks for posting this.

Actually, once you install modelines after enabling EDID emulation, composite sync will work correctly without needing to force positive polarities. But yes, if you only enable EDID emulation it won't sync automatically, I should add this information to the guide.
Yes, i forgot to mention that. The modelines can be either way, it's the monitor.ini file that is important to have in positive polarity before enabling edid emulation. After edid emulation is turned on, the polarity of the modelines or the monitor.ini becomes irrelevant.
Title: Re: A note about composite sync and post hd5000 cards.
Post by: Paradroid on October 13, 2019, 08:05:09 pm
Hi guys,

I have successfully used composite sync in the past but over the weekend I struggled to get it going using an HD 5450 with an RGB-modded Sanyo 25 inch TV.

I tested the same TV with another computer that has a HD 4350 installed and all good there: picture synced fine. Anyway, the mystery of why the HD 5450 wouldn't work brought me here...

In summary, is this what we're saying to do?
Cheers!
Title: Re: A note about composite sync and post hd5000 cards.
Post by: Foxhole on October 14, 2019, 08:30:08 pm
Quote from: Paradroid on October 13, 2019, 08:05:09 pm
Hi guys,

I have successfully used composite sync in the past but over the weekend I struggled to get it going using an HD 5450 with an RGB-modded Sanyo 25 inch TV.

I tested the same TV with another computer that has a HD 4350 installed and all good there: picture synced fine. Anyway, the mystery of why the HD 5450 wouldn't work brought me here...

In summary, is this what we're saying to do?
  • Set polarities to positive in the monitor.ini file (or is this unnecessary?)
  • Install the EDID emulation.
  • Enable composite sync.
  • Generate and install modelines.
Cheers!

Yes, the monitor.ini was the important part, it should be set to positive and then enable edid emulation.
Title: Re: A note about composite sync and post hd5000 cards.
Post by: Paradroid on October 14, 2019, 08:35:25 pm
Quote from: Foxhole on October 14, 2019, 08:30:08 pm
Yes, the monitor.ini was the important part, it should be set to positive and then enable edid emulation.

Cheers Foxhole! I'll give that a go once I've got it all setup again on the workbench.
Title: Re: A note about composite sync and post hd5000 cards.
Post by: Paradroid on October 24, 2019, 05:07:07 pm
Quote from: Calamity on August 23, 2019, 04:45:04 am
Actually, once you install modelines after enabling EDID emulation, composite sync will work correctly without needing to force positive polarities.

I finally found the time to have a good play around with this last night and I cannot get my TV to sync to the output of this HD 5450 not matter what I try.

Do you think it's possible that some cards simply don't support composite sync?

My experience in the past with composite sync has been far easier. Issues seem particular to this card.

I'm at the point where I'm looking at wiring up a sync combiner... which is a shame since the composite sync revolution has mostly done away with this need.
Title: Re: A note about composite sync and post hd5000 cards.
Post by: Zebra on October 26, 2019, 05:59:17 pm
I had no issues getting composite sync when I used a 5450. Have you been able to confirm it's working via RGBHV?

Either way, I recommend getting an Extron RGB interface for use with GM. It solves nearly all sync related issues and has a display showing you the res and refresh rate so you can confirm everything is working correctly. They can be found on ebay for $10 - $15.