1 Topic by 002

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Topic: Can't get any interlaced resolutions to work.

Hi,

I've been using CRT Emudriver for many years on various systems now but this one has me stumped. First of all I will describe my setup.

  • I have a PC running Windows 10 in Test Mode.

  • It has a discrete low profile AMD Radeon R9 M360 that has two DisplayPort outputs only (card looks like this: https://i.imgur.com/t5bcGuu.jpg)

  • I am using a DisplayPort x VGA adapter which connects to an input on my Extron RGB 203

  • The Extron RGB 203 runs out to my Olympus OEV203 via 4 x BNC RGBS

So what I'm trying to do is get 480i and 576i resolutions working on my monitor.
I can install the modelines without any issue and they report to me fine in arcade_osd.exe, however, when I try to switch to them I have a blank screen with 'NO SYNC' on my monitor - and the Extron doesn't even report the vertical and horizontal scan rates like it does if I use a progressive scan resolution. It just says 'NO SIGNAL'.

The modelines I'm trying are:

720 x 576 @ 50.000000 aux
720 x 480 @ 60.000000 aux


but I've also tried these (in vain):

720 x 576 @ 25.000000 aux
720 x 480 @ 29.000000 aux

I'm thinking that the issue might be with the DisplayPort to VGA adapter. It's one I got from Jaycar here in Australia. I'd provide the link to what it looks like but am limited to one link per post it seems.

Happy to provide any further info on request. Thanks!

2 Reply by 002

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Re: Can't get any interlaced resolutions to work.

I might have just found the answer to my question in a forum thread on reddit.

https://old.reddit.com/r/crtgaming/comm … splayport/

3 Reply by 002

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Re: Can't get any interlaced resolutions to work.

For anyone stumbling on this thread. The issue was indeed the DP to VGA adapter.

I got a new card on eBay (Low profile AMD Radeon R5 240) and it works flawlessly with interlaced resolutions as it has a DVI port which supports a passive VGA > DVI adapter.

The final piece of the puzzle was that my interlaced resolutions were SUPER jittery and that was solved by disabling DDSP using the dip switches on the Extron RG203.

4 Reply by Calamity

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Re: Can't get any interlaced resolutions to work.

Only a few DP to VGA adapters actually work for interlace and low dotclocks. Basically the ones based on the Realtek RTD2166 / 2168 chip. Like this one.