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Software Support => GroovyMAME => Topic started by: cornhairboy on September 15, 2017, 07:26:32 am

Title: Second crt has picture jumping with crt emu driver via vga to scart lead
Post by: cornhairboy on September 15, 2017, 07:26:32 am
Hi all

Need some help. Ok I'm running a ultimate scart adapter that works amazing with crt 1. My second crt is using a vga to scart cable (which I had working many years ago via sci tech display doctor settings) but using calamity amazing vga driver I either get no picture or it jumps everywhere.

Please please any support would be great!!!!


Thanks
Title: Re: Second crt has picture jumping with crt emu driver via vga to scart lead
Post by: cornhairboy on September 15, 2017, 07:36:18 am
Just an update,

If I try to EDID emulation I get no picture at all. (I presume the ranges are too high) my tv is an Toshiba 36zp18. Thanks
Title: Re: Second crt has picture jumping with crt emu driver via vga to scart lead
Post by: cornhairboy on September 15, 2017, 01:41:43 pm
Just an update,

If I try to EDID emulation I get no picture at all. (I presume the ranges are too high) my tv is an Toshiba 36zp18. Thanks

OK so I've managed to slow the vertical scrolling by forcing the modelines towards 50hz but the lowest I can get is 52hz. Now, this tv is a 100hz scan rate, can I get it running at that instead?
Title: Re: Second crt has picture jumping with crt emu driver via vga to scart lead
Post by: Recapnation on September 15, 2017, 03:51:39 pm
Sounds like a sync. signals issue. Check if you can use the UMSA from "CRT 1" on the Toshiba TV set to confirm. Normally, a 100-Hz set will display ~60-Hz modes, but it's not the best set for that purpose due to the process involved.
Title: Re: Second crt has picture jumping with crt emu driver via vga to scart lead
Post by: cornhairboy on September 15, 2017, 04:10:43 pm
Sounds like a sync. signals issue. Check if you can use the UMSA from "CRT 1" on the Toshiba TV set to confirm. Normally, a 100-Hz set will display ~60-Hz modes, but it's not the best set for that purpose due to the process involved.

Yep, the ultimate scart adapter works fine on the Toshiba. Tried this a couple of days ago, how can I get round this problem. I really don't want to have to buy a second Ultimate scart adapter,  I really hoped my specialist vga cable would work again....

Any suggestions next
Title: Re: Second crt has picture jumping with crt emu driver via vga to scart lead
Post by: Recapnation on September 15, 2017, 04:18:28 pm
You'll need to fix the cable, then?

Title: Re: Second crt has picture jumping with crt emu driver via vga to scart lead
Post by: cornhairboy on September 15, 2017, 04:23:38 pm
The cable is fine, it cost me £60 8 years ago. It doesn't make sense
Title: Re: Second crt has picture jumping with crt emu driver via vga to scart lead
Post by: cornhairboy on September 15, 2017, 05:41:44 pm
Picture now stable at pal 50hz settings but have a black bar across the middle...... Hmm it definitely prefers 50hz
Title: Re: Second crt has picture jumping with crt emu driver via vga to scart lead
Post by: cornhairboy on September 15, 2017, 05:56:25 pm
Picture now stable at pal 50hz settings but have a black bar across the middle...... Hmm it definitely prefers 50hz

Even stranger is when I try a different interlaced resolution the black bar moves. It almost as if the v sync can't lock.

I think I'm going to give up now, get a vga to component converter and run via component,

Doesn't matter too much I still have my main crt on my machine
Title: Re: Second crt has picture jumping with crt emu driver via vga to scart lead
Post by: Calamity on September 15, 2017, 05:58:26 pm
The cable is fine, it cost fme £60 8 years ago. It doesn't make sense

You're missing vertical sync.

Your cable doesn't combine hsync and vsync into composite sync (c-sync)

Either:

- Get another cable.
- "Mod" your cable.
- Install CCC and try to enable c-sync using it (good luck)
Title: Re: Second crt has picture jumping with crt emu driver via vga to scart lead
Post by: cornhairboy on September 16, 2017, 02:58:01 am
The cable is fine, it cost fme £60 8 years ago. It doesn't make sense

You're missing vertical sync.

Your cable doesn't combine hsync and vsync into composite sync (c-sync)

Either:

- Get another cable.
- "Mod" your cable.
- Install CCC and try to enable c-sync using it (good luck)

OK that makes sense I remember some setting in sci tech display doctor that did this.

OK so next question which is the best cable to get and where from

How easy is it to mod and is there any tutorials?

Thanks again
Title: Re: Second crt has picture jumping with crt emu driver via vga to scart lead
Post by: cornhairboy on September 16, 2017, 04:09:45 am
Ok so here is the scart I have taken pictures of....

Does it look like the v and h sync have been put together?

Thanks
Title: Re: Second crt has picture jumping with crt emu driver via vga to scart lead
Post by: Calamity on September 16, 2017, 04:55:32 am
Does it look like the v and h sync have been put together?

No. I'd say the yellow cable is h-sync. You should see two cables going to pin 20, check this: http://www.geocities.ws/podernixie/htpc/cables-en.html (http://www.geocities.ws/podernixie/htpc/cables-en.html)

That's the most simple schematic. Other schematics use a few other components to provide a better quality c-sync.
Title: Re: Second crt has picture jumping with crt emu driver via vga to scart lead
Post by: cornhairboy on September 16, 2017, 05:09:16 pm
Thanks calamity,

I've decided to bite the bullet and purchase a ready made scart with vsync all completed from retr80s on eBay.

I will get you the results as soon as I receive it!