Going from 70Hz to 60Hz always creates timing problems in some 70Hz specific DOS games, keep that in mind.

StriderTR wrote on 2023-05-14, 06:34:

First off, Hello! […]
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First off, Hello!

Long time browser, first time poster, and an old classic geek!

After browsing this thread, and others, in search of a reasonably priced way of capturing DOS resolutions over VGA. I think I've settled on the Extron RGB-DVI 300, but have a quick question I hope a user of that device, or the HDMI version, can tell me.

• It's going to be used to upscale the VGA DOS output from a Win95 powered retro mini PC (linked below) so I can then feed that into an inexpensive HDMI/USB capture device for short video clips and screenshots.

• It will not be feeding my display, so frame lag is not important to me. I will be splitting the VGA signal, one going to the scaler, one directly to my display.

• I went with the DVI version and intend to just use a DVI to HDMI dongle. The DVI versions are more readily available at more reasonable prices, in better condition, and with their OEM power supplies at the moment on eBay.

Specifically, this is the one I bought and waiting to arrive: https://www.ebay.com/itm/353970649033 $40 shipped.

My question is...

If I read all this correctly, it will scale DOS resolutions like 320x240 and 740x400@70 and output my selected resolution at 60Hz? Do you foresee any major issues?

OK, that's 2 questions... 🤣

If so, it will fit me needs perfectly. I'm not going for top notch quality here, just captures to use on a simple blog. If not, I'm not out much, and I can use it for other things.

This is the WIn95 system in question. https://theclassicgeek.blogspot.com/2023/03/m … -with-epia.html

Forgive me if I typo'ed anything, it's 1:30AM and a long day. 😜

Thank you very much in advance!

Sounds like you made the perfect choice. The Extron device outputs a steady 60Hz regardless of input refresh and does so without issue.

agent_x007 wrote on 2023-05-14, 11:08:

Going from 70Hz to 60Hz always creates timing problems in some 70Hz specific DOS games, keep that in mind.

Very true. Hence why I'm splitting the VGA output and only using the scaler for capture. To bring the signal into a range my cheap capture device can handle. 😀

The other side, without the scaler, will go directly to my display.

maxtherabbit wrote on 2023-05-14, 15:10:

Sounds like you made the perfect choice. The Extron device outputs a steady 60Hz regardless of input refresh and does so without issue.

Excellent! I'm glad to hear it.

Now, I just have to wait for it to arrive. 😀

Have that same model, which was very handy when trying to diagnose and solve a weird video card that had a non-standard refresh rate issue (was able to scale it pretty well)

What's also great with these, is you can still buy new replacement parts for it direct from the oem ( in my case, I was able to buy replacement knobs that were missing from mine)

Well, I got my Extron Rgb-dvi 300 RGB to DVI Scaler and it works great, but I ran into another problem.

None of the 3 "cheap" HDMI to USB capture devices work with the signal coming out of the scaler. It simply outputs a black screen.

The Extron Rgb-dvi 300 RGB outputs a single-link DVI signal, I've tried both an SL DVI to HDMI cable and an adapter I have, nothing. I'm assuming the capture devices are my problem since I've directly connected a monitor to the scaler using both adapters and they all work perfectly.

So, stupid question, is this a single-link DVI issue? Or something else? Any ideas welcome!

My basic setup, Win95/DOS PC to Extron, Extron to HDMI/USB capture device via adapter cable. OBS to capture.

I have verified the capture devices work using an active VGA to HDMI adapter, and it captures that signal, and any other HDMI signal, fine as long as it's 800x600 or higher.

EDIT #1: The HDMI pass through also shows no signal, but works fine using anything but the scaler. Very odd...

EDIT #2: Also, changing the output to 720P, 1080P, 1080i, 60Hz, 59.97Hz, "HDMI Data" on or off, have no effect. No setting changes in the Extron make any difference. Even the test pattern is not seen by the capture device.

Thanks in advance for any advice! 😀

Check if capture from Extron works from within Windows using "standard" resolutions (640x480/1024x768 and with different refresh rates [30-75Hz range]).

StriderTR wrote on 2023-05-14, 06:34:

• I went with the DVI version and intend to just use a DVI to HDMI dongle. The DVI versions are more readily available at more reasonable prices, in better condition, and with their OEM power supplies at the moment on eBay.

I've been meaning to thank you for this tip! I had a saved eBay search for the RGB-HDMI for quite a while after seeing them mentioned in this thread and was disappointed they were always so expensive, so I never bothered to read up on the device any further as I figured I'd never get one, but maybe if I had I'd have realised there was the DVI model too. Now I have one too, thanks!

StriderTR wrote on 2023-06-14, 04:44:

None of the 3 "cheap" HDMI to USB capture devices work with the signal coming out of the scaler. It simply outputs a black screen.

I had success with mine, which is not just cheap but also very bad quality. It claimed to be USB 3 but isn't and it has a weird USB A-A cable. Also - possibly relevant to you - it seems to freeze, or perhaps does something to make Video4Linux freeze, both with the Extron and with some other cheaper converters I'd tried it with. I haven't done any proper capture yet and was just using the qv4l2 (QT V4L2) utility to view what was coming out of the device, and sometimes to just save the raw data. It seems that when I set the capture device to use higher resolutions it freezes more often. If I recall correctly the video stops updating, and then if I quit and restart qv4l2 it can no longer open the device or something, and I think "dmesg" shows some USB errors. I end up having to disconnect the USB connection to the device, restart qv4l2, then reconnect, or something like that. Maybe even have to disconnect its HDMI input. I got mine from Amazon a year or two ago and it's apparently made by "TenYua".

agent_x007 wrote on 2023-06-14, 06:25:

Check if capture from Extron works from within Windows using "standard" resolutions (640x480/1024x768 and with different refresh rates [30-75Hz range]).

I've tried all the different output settings available to me, no luck. 1920x1080, 1280x720, 60Hz, 59.97Hz, etc. All supported by all 3 capture devices. They also work at those resolutions with other sources, like a Raspberry Pi, C64 Mini, etc. Just not with the Extron output for some odd reason.

doshea wrote on 2023-06-14, 08:58:

I've been meaning to thank you for this tip! I had a saved eBay search for the RGB-HDMI for quite a while after seeing them mentioned in this thread and was disappointed they were always so expensive, so I never bothered to read up on the device any further as I figured I'd never get one, but maybe if I had I'd have realised there was the DVI model too. Now I have one too, thanks!

Hah, you're welcome! I came upon it when browsing eBay and figured I would try and save a bit and get the DVI model. 😀

doshea wrote on 2023-06-14, 08:58:

I had success with mine, which is not just cheap but also very bad quality. It claimed to be USB 3 but isn't and it has a weird USB A-A cable. Also - possibly relevant to you - it seems to freeze, or perhaps does something to make Video4Linux freeze, both with the Extron and with some other cheaper converters I'd tried it with. I haven't done any proper capture yet and was just using the qv4l2 (QT V4L2) utility to view what was coming out of the device, and sometimes to just save the raw data. It seems that when I set the capture device to use higher resolutions it freezes more often. If I recall correctly the video stops updating, and then if I quit and restart qv4l2 it can no longer open the device or something, and I think "dmesg" shows some USB errors. I end up having to disconnect the USB connection to the device, restart qv4l2, then reconnect, or something like that. Maybe even have to disconnect its HDMI input. I got mine from Amazon a year or two ago and it's apparently made by "TenYua".

The specific 3 that I have on hand are all Amazon specials, and otherwise work good for standard HDMI capture. Heck, they even capture the output from an active VGA to HDMI adapter on my Win95 PC and Z80-MBC2 Homebrew, but like I said, the output resolution is 800x600 or higher.

These are the capture devices I have:

https://www.amazon.com/gp/product/B0895N9KM5/
https://www.amazon.com/gp/product/B08SBTK4QH/
https://www.amazon.com/Mirabox-Passthrough-Ni … /dp/B08QJ84JNP/

This is the VGA to HDMI adapter I sometimes use that I reference above: https://www.amazon.com/gp/product/B08GZ159FJ/ (It does not work with "DOS resolutions" at all, hence the search for something better)

Maybe I need to see if I can capture under Ubuntu on my mini test bench PC, a little Zotac Zbox Nano CL320 I use for my logic analyzers, USB oscilloscope, Arduino programming, PCB design, etc. Just to eliminate any possible issues using OBS. I just haven't thought to do so since as soon as I try and capture from any other source I have, other than the Extron, it works perfectly.

On a side note. both of the HDMI capture devices I have with pass-through also have those weird USB A to A cables. One claims to be USB 3.0 and 4K, but I've never tried it at anything over 1080P and it's always hooked up on USB 3 on my daughters PC. The other two don't make such claims, even though the other pass-through device has a blue port and cable, but it's definitely USB 2.0 and only works up to 1080P.

I've also noticed some issues with these cheap capture tools, at least with OBS. OBS wont see the stream if you start OSB before plugging in the capture device. They do sometimes freeze, but that's pretty rare in my case. Either way, I've got into the habit of disconnecting the device, reconnecting it, and restarting OBS anytime I change the source. I have ran into instances where it won't capture a new source without going through that process. So, during all my "testing" trying to figure out why none of these things can see the output from the Extron, I did that over and over again, just to try and eliminate it as a possible cause.

While I have little hope trying to capture on Linux will work, I plan on giving it a try, may even try different Windows software, just to cover all my bases. If I can't get it working, I guess I'm stuck looking at yet more options. 😀

StriderTR wrote on 2023-06-14, 14:01:

agent_x007 wrote on 2023-06-14, 06:25:

Check if capture from Extron works from within Windows using "standard" resolutions (640x480/1024x768 and with different refresh rates [30-75Hz range]).

I've tried all the different output settings available to me, no luck. 1920x1080, 1280x720, 60Hz, 59.97Hz, etc. All supported by all 3 capture devices. They also work at those resolutions with other sources, like a Raspberry Pi, C64 Mini, etc. Just not with the Extron output for some odd reason.

Bad writing on my part, I meant input resolution, not output one.
In short : Does it work when retro PC outputs 800x600/1024x768/1280x720 into your scaler.

So : 1280x720 => Scaler => XYZ* => Capture
1024x768 => Scaler => XYZ* => Capture
800x600 => Scaler =>XYZ* => Capture
(*XYZ = whatever setting scaler can does)

agent_x007 wrote on 2023-06-14, 15:48:

Bad writing on my part, I meant input resolution, not output one. In short : Does it work when retro PC outputs 800x600/1024x768 […]
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Bad writing on my part, I meant input resolution, not output one.
In short : Does it work when retro PC outputs 800x600/1024x768/1280x720 into your scaler.

So : 1280x720 => Scaler => XYZ* => Capture
1024x768 => Scaler => XYZ* => Capture
800x600 => Scaler =>XYZ* => Capture
(*XYZ = whatever setting scaler can does)

Sadly, no, I get the same result.

The default Win95 desktop resolution I'm using on that system is 800x600 (60Hz), but I have tried 1024x768 and it made no difference.

To be honest, even if it did work, it would not work for my needs since I want to upscale 640x480 or lower so it can be captured using modern tools. This Extron scaler seems to have no problems doing just that, it seems to scale "DOS resolutions" like 320x200 and 720x400 just fine, outputting a solid 1280x720 or 1920x1080 image at 60Hz. I only run into a problem when I go to capture that output using these cheap HDMI capture devices.

I'm currently looking at dedicated DVI capture options in case I can't get this to work. 😀

You could try getting Avemedia 4k GC573 (supports high refresh on low resolutions), since DVI is basicly HDMI.
But not sure if you can get it in your budget 😒

Well, I just tried it on my Ubuntu machine, OBS ( V4L2), and I got the same result.

agent_x007 wrote on 2023-06-14, 16:14:

You could try getting Avemedia 4k GC573 (supports high refresh on low resolutions), since DVI is basicly HDMI.
But not sure if you can get it in your budget 😒

Yeah, I'm at a loss as to why this isn't working. Something about the signal from that Extron these things don't seem to like. I don't think it can be the fact I'm using DVI to HDMI adapters? Like you said, it's basically the same.

Still, there are straight DVI capture options out there on the used market I'm looking into, some around $50 or so. I mean, I hate to blow $50 to find out it's some other issue, but that's really the only other option I have at the moment.

Sure, I will have more capture devices than any one person should ever need, but since I do a lot of retro tinkering anyway, at least they'll get used. 😜

EDIT: I'm seriously looking at this DVI capture device from Startech: https://www.startech.com/en-us/audio-video-pr … ts/usb32dvcapro

It looks like it will work, and I can get one much cheaper used. Thoughts and opinions welcome!

Well, the deed is done. Wish me luck! I'll post how it works out.

I ordered one off eBay: https://www.ebay.com/itm/404164032853

$52.49 shipped.

"Used - In mint, unused condition. Pictured cables included." Reputable seller. For a $160+ item I think it's a fair deal. 😀

FYI Update:

My eBay StarTech DVI capture device arrived, and so far, it seems to work great with the Extron scaler! I made the gifs below from sample captures I did to test it out. I have since adjusted brightness/contrast settings since the captured feed is coming off an powered splitter and I couldn't be happier. For what I want to do, it's perfect. The DVI pass-through also works as it should.

$50 well spent in my humble opinion!

VGA output > splitter cable > powered splitter > monitor
VGA output > splitter cable > Extron > Capture > OBS

Did someone tried HDmatters SVA2HDS (https://www.aliexpress.com/item/1005005214187411.html) with VGA and DOS games?
Cant find any review of this device, except some comments from Amiga users and YT video captured from Sega MD (https://www.youtube.com/watch?v=jjRwQaafpq8).

Dusko wrote on 2023-03-28, 03:34:

darry wrote on 2020-06-18, 02:46:

After lots of comparisons between manuals (specs and OSD layout) and physical layout, I am about 99% convinced that the Startec […]
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After lots of comparisons between manuals (specs and OSD layout) and physical layout, I am about 99% convinced that the Startech VGA2HDMI Pro (first version) is a rebranded CYP SY-P293 . If that is the case, the SY-P293 should have undocumented 720x400@70Hz input support (because the VGA2HDMI Pro does) and documented 1024x768@70Hz output support .

So, in the interest of science, I am seriously considering buying one . Should I ?

I already have a
- Gefen VGA to DVI Scaler PLUS (dead)
- OSSC rev. 1.6
- Extron RGB-DVI 300
- Crestron HD-SCALER-VGA-E
- CYP CP-254
- CYP CP-253 (in the mail)

Or do I need to seek help ?

It's been a while since you posted this! I hope you are doing fine.
I wanted to ask you, out of all those scalers, which one worked the best?

Hi,

I'm doing well, thank you .
I've been busy with other things.

For my use case OSSC + a monitor with 4:3 support is as good as it gets . Extron RGB-DVI 300 is great too, if one can deal with no 60Hz 70Hz output and scaling that isn't as sharp as a line multiplier (such as OSSC).

When OSSC Pro comes out (it is currently "on pause", AFAIU), I might consider it and/or other potential options, such as these https://www.retrotink.com/ .

EDIT: Corrected typos

I also got a VGA to HDMI adapter, that works even on 720x400 and 320x200, and also a HDMI capture stick. Also the old VGA-HDMI adapter I had (that broke, the problem was yellow tint on image and blue channel was absent) didn't supported 720x400 and 320x200 video modes. Now with the new VGA-HDMI adapter I can capture old DOS games and see the PC BIOS.

RetroPC_King wrote on 2023-09-08, 04:53:

I also got a VGA to HDMI adapter, that works even on 720x400 and 320x200, and also a HDMI capture stick. Also the old VGA-HDMI adapter I had (that broke, the problem was yellow tint on image and blue channel was absent) didn't supported 720x400 and 320x200 video modes. Now with the new VGA-HDMI adapter I can capture old DOS games and see the PC BIOS.

Does it convert 70Hz to 60Hz or pass it through as is ?

Can you share a link ( or at least some keywords that one can use to find it) to where you got it from ?

Yeah, I'd be curious as well, for the new adapter looks suspiciously very much like the piece of sh... cheap Chinese adapter I got off eBay a few months ago and promptly threw away in disgust...

RetroPC_King wrote on 2023-09-08, 04:53:

I also got a VGA to HDMI adapter, that works even on 720x400 and 320x200, and also a HDMI capture stick.

I hope you are more lucky than me with that capture stick, two broke on me because they overheat very much.