Dual monitor setup questions.

[Milsancho]

Hello and first off, thanks to Calamity and assistants for mantaining and creating these awesome tools.

I'm going to install GM on a setup with two monitors, a PC CRT monitor (2 VGA inputs) and a 15khz RGB TV. I have two Radeon cards and I'm reading that I should discard the HD4000 series even if it has two analog output, so my other option is an HD6500 something, which only have one VGA output, as the other is DVI-D, with an HDMI as well.

I'm just looking for recommendations for DACs, as I've read there're some turds there in the market. I don't know if I'd rather use a DVI-D to VGA instead an HDMI to VGA. The only thing if possible, I'd prefer something you can easily buy in Europe.

Cheers.

[Milsancho]

So nobody is using a DAC with good results here? Maybe I should ask in the Monitor/Video Forum but since it's for a dual 31/15khz usage with Emu Driver, I thought more people here would be in the same situation. I'm sure I'll be facing more questions and didn't want to spam the forum with more than one thread either.

Thks.

[SuperMagoAlex]

Hi,
I have a dual monitor setup 15khz (1 horizontal Sony Trinitron 15" and 1 vertical Commodore 1084S), and I'm using a DVI-D to VGA active adapter (Amazon).
It works well and I have pixel perfect on both monitors, but when I start a game I have to turn off the inactive monitor, otherwise a little wave effect appears on the monitor I'm playing on.

[Milsancho]

Hi! Thanks for the input. So which brand and model is your converter? I'm sure if it works at 15khz it'll have no issues at 480p and beyond.

[buttersoft]

Most older generic HDMI-to-VGA dongles used the AG6200 chipset. See pic below. This was designed for much higher bandwidths and, everything else being equal, works perfectly at 15kHz. However, lots of manufacturers have switched to cheaper chips now, especially in unbranded adapters. That's the problem linking to anything generic, as the seller won't know what's inside it and how it works. I bought more than a dozen looking for one to use for the MiSTer with direct video, and they all failed. I then grabbed about twenty older ones when my workplace had an E-waste clearout, and five of them worked with both separate sync and composite sync, and a further one worked with separate sync only.



In this style, do not buy anything new and generic that does not list the AG6200 chip. Do not buy Tendak. Brand-name ones like ugreen or Comsol or Belkin are a better bet, but still pretty random.

This one below lists the right chipset. I bought a different Vention one that also listed the AG6200 chip, and it works. There are no guarantees this one will, but it's worth a shot.
https://ventiontech.com/products/hdmi-to-vga-converter-black?variant=43107908518054

EDIT: Hmmm, it occurs to me to mention that higher dotclocks from super resolutions, or, say, from Radeon R7/R9 500 series cards with higher dotclock minimums, might mean a few more adapters work? Someone would need to test that to confirm.

[Milsancho]

Thanks for the incredibly insightful reply, buttersoft! That's all I wanted to know. It's a shame that even DACs have become legacy devices and current options are low-grade substitutes.

The issue with these, as I understand, is just for 15khz use? I'll be safe if the lowest mode I'll need is 480p60 (or 240p120)?

At any rate, I should avoid something like this ("Oldboytech" in the US, I believe):

https://www.amazon.de/-/en/gp/product/B08CW57STX

[buttersoft]

The issue with these, as I understand, is just for 15khz use? I'll be safe if the lowest mode I'll need is 480p60 (or 240p120)?

The makers of these cheaper converters never aimed a product at 15kHz video conversion, no. Further, that one you linked to doesn't even list 480p in its supported resolutions. And when it comes to other dongles/converters i really have no idea. I can only tell you what i've been through and what i found out from it - hence the post above

There are going to be more expensive converters out there, old studio or broadcast gear even, i just don't know what to recommend, there.

[Milsancho]

So I'm reading quite a bit and I think I'd rather buy another card. The HD 4000 is not recommended for Windows 7 and the HD 6000 has this VGA port with cable:



which apparently is not good.

So a couple of questions, if you bear with me:

- When it's a VGA port like that, does it mean that it's using an internal DAC?

- Does the Display Port also have low dotclock incompatibility when converted to analog?


Though this is somewhat long ago, I've read Calamity that low dotclock incompatibility happens with digital outputs (implying all of them). Must I assume this is not really the case nowadays? I'd be interested in displaying natively 256x240 and the likes, so I'd like to make sure given that what I was dicussing with buttersoft was just '15khz' compatibility.


Edited to add: Nevermind the second question as I think I got the answer. DP itself is not problematic with low dotclocks but you need lots of luck with the converter.


I'll add another question, then: What's a good card (in terms of power) for Dolphin and Demul emulators if you're going to just use 480p with them? And for Type X and PC-based games? Would an HD 5750 suffice? Is it more capable than an HD 6570, video outputs apart?

[buttersoft]

a PC is a digital, so any video card with an analogue video output, is using an internal DAC, perhaps made partly out of discrete components if you go back far enough

Nothing wrong with either of those cards, i don't think, though a 5000-series card might have two analogue outputs, as i believe you noted before. Personally i'd look at something like a 7870 or 7950 for a bit more grunt, maybe, or if you're after lower power usage or low profile, maybe an R7 250.

I have a question for you though - why use crt_emudriver for 480p? Can't you make your system output that already? Can you not just add custom modelines with a tool like ToastyX's CRU and tell the emulators not to scale? I'm almost completely clueless when it comes to 480p on crt_emudriver :/

[Milsancho]

a PC is a digital, so any video card with an analogue video output, is using an internal DAC, perhaps made partly out of discrete components if you go back far enough

The HD 6570 I already have has the VGA port like this, which has so many detractors here:



But maybe it's not related to the internal DAC?

Nothing wrong with either of those cards, i don't think, though a 5000-series card might have two analogue outputs, as i believe you noted before. Personally i'd look at something like a 7870 or 7950 for a bit more grunt, maybe, or if you're after lower power usage or low profile, maybe an R7 250.

Dual analogue output is really a factor in my needs, though I don't really know if a more powerful card like those are better for Type X and PC-based arcade games or if it's no use because these never had powerful GPUs to begin with. Or what's the minimum a modern PC game like Shredder's Revenge generally demands... At least I do know that for Vulkan API compatibility I need HD 7750 or higher, but I don't really know if that API would do anything for me... Oh well.

Anyway, I'll ask here in case anybody has experience with this one:



in regards to dual analogue output.

I have a question for you though - why use crt_emudriver for 480p? Can't you make your system output that already? Can you not just add custom modelines with a tool like ToastyX's CRU and tell the emulators not to scale? I'm almost completely clueless when it comes to 480p on crt_emudriver :/

Well, the idea is having a single computer for everything gaming (considering that I've no interest in modern 3D) with two monitors (+31khz and 15khz CRTs), so I thought that CRT Emudriver is the all-round solution. I've also read that, aside of other emulators, there're not few video modes Mame requires that will benefit from a PC CRT whilst not being standard PC resolutions, like 512p modes.

[Milsancho]

So before buying anything, I'm trying the dual analogue output with an HD 4550 first (so no Edid emulation). I have installed 15khz modes only though, and I'm wondering, if I install 31khz modes (despite having already 15khz versions of some of them), the process is just setting extended desktop for the new display (a 31khz PC CRT). This monitor is not the one used in the installation process and it doesn't seem to be acknowledged by Windows as such.

Will Windows automatically set a compatible video mode for this new monitor "1" during the desktop extension process? Will I be able to use Arcade OSD to set modes in this extended desktop configuration?

Thks.

[Recapnation]

ED. Nevermind; I misread your post.

[Milsancho]

In the case my previous post is a bit convoluted, I'm just having a monitor detection issue. Windows (7) isn't acknowledging properly I have a VGA monitor connected with the HD 4550 and Emudriver.

The monitor works fine as the BIOS is displayed when booting the system, but as mentioned it's not the one used when I did the emudriver installation. I don't think that should matter anyway as both are VGA PC monitors.

When I try to make a desktop switch (in order to use what Windows calls display "1" instead of "2") through Windows' display management app, the VGA monitor is shown as "generic no PnP monitor" (which should not be a problem) and I can't pick a resolution mode for being greyed out (I can for the 15khz monitor, though).

Any idea as of how to force monitor detection in this case? I guess I could try reverting the process explained here: http://geedorah.com/eiusdemmodi/forum/viewtopic.php?pid=1019#p1019
but really, I'm afraid of ending up with no picture whatsoever.

[haynor666]

Did You enabled EDID emulation on both analog outputs ?

[Milsancho]

I think I didn't. I'm using an HD 4550 so that's not really possible?

[haynor666]

Sadly this option is not available for HD4xxx cards. But there are plenty cheap HD5xxx on market so it's worth to replace old one.

[Milsancho]

So if possible, Calamity, could you please let me know your opinion on this, please? Is there a way I can force a VGA monitor detection with a HD 4xxx series once the monitor 2 is running at 15khz? A couple of posts back there more details if needed.

[Milsancho]

I'm still trying, mind. I'm sure I'm missing something elementary as I refuse to believe dual video output is not possible on an HD 4550 with Emudriver, or just to extend the desktop with it. I've found that Video mode maker's video card tab has display1 picked ("enabled") on the Device menu, while display2 is "disabled". Could this be related to my issue of not being able to pick a resolution mode on Windows for the second (VGA) monitor (and therefore, succesfully extend the desktop), as described before? Windows says my 15khz display in use is display2, not 1.


In the case I change my card and reinstall Emudriver, I should use AMD Cleaning utility right after uninstalling it first, right? What should I do when Windows asks me to run Windows Update after it founds itself with no video card driver installed considering it's an offline setup?

[buttersoft]

Well, i'm not able to answer all of the technical questions there, is only because it's been too many years since i tried to do anything like this. It's important to remember that this is an edge case in what is already a very niche hobby, so the chances of someone just knowing the answer might be small.

I use a program called display changer 2 to force-change certain monitor configs. Just resolutions in my case, but it might be able to force modes on different monitors. You probably need to be able to set things up first in some way tho, to capture the config you want.

I would simply re-install Windows then install crt_emudriver, that's the cleanest way. And as a rule, it's always better to get your drivers/monitors set up to deliver the video modes you want first, then configure your emulators and controls and frontend after that. Saves doing everything over. First time through everyone makes a lot of mistakes, though

Windows update can't do anything if you're not online? Either way i wouldn't let it run. You could use something like winaerotweaker to disable updates, and hopefully that wouldn't have any knock-on effects.

[Calamity]

Hi Milsancho,

First of all, please relax.

You've decided to go against all advices and use an HD 4000 generation card for modern Windows (post-XP) so expect troubles.

Monitor detection was a plague for these gpus so back then I decided to patch the drivers in order to FORCE monitor detection in all analog outputs. This is why you'll see a "generic no PnP monitor" even if the output is disconnected. This allows you to go into Windows display manager and extend the desktop whether or not there's a physical monitor connected.

Then you will face a random situation as Windows tries to restore the last known working configuration and may send your desktop to the unwanted monitor until things finally settle. If you just accidentally boot the pc with a different monitor layout (e.g. having unplugged one of the screens) things will turn random again.

Having suffered this myself, I wrote the "algorithm" that you can find in Eiusdemmodi's guide, that works for the most typical configuration (single monitor).

Believe it or not, all this trouble caused by forced detection was less bad than having to physically add resistors to trigger detection.

To make things more interesting, you want to use 15 and 31 kHz monitors at the same time. You can do it, but on this older hardware you can't install different custom modes per output, so all of them will be mixed and available for both outputs.

In your situation, I'd be using a newer card like the ones you posted above. Then use the VGA for 15 kHz with EDID emulation, and a suitable HDMI->VGA adapter for 31 kHz, since you don't need low dotclocks for this (HDMI by design has a lowest dotclock of 25 MHz).

PD: I've used cards with ribbon cable for VGA all the time, no issues here.

[Milsancho]

Thanks for the answers, guys.

Glad to read the ribbon cable cards are fine. Some people here warn about possible noise with these.

I'll use a newer card and forget, then. I picked the 4550 just to check how the dual analog output works as it was around, while I decided what better card and what DAC to use. The problem now is, while I haven't made a lot of non Windows configuration as buttersoft mentions, I've wasted quite a bit of time disabling Windows services, installing drivers and fine-tuning the OS, so I'd rather try not reinstalling Windows 7.

Would you please bare with me a little more and let me know the second best way to uninstall and reinstall a Emudriver? I've seen AMD cleanup utility suggested, but then, should I check for anything before reinstalling? My question about Windows Update and offline installation meant that, once the OS finds no video card installed, if it'll need an update to get them anywhere before being able to proceed with Emudriver or something.

[Calamity]

Just use the emudriver setup program for uninstalling the driver.

[Milsancho]

Cool, thks. Just to make sure, you mean to run Setup.exe in the CRT Emudriver folder as if I were to install it, right? That applies even for an old version like beta 8 (don't ask) as well?

In a more interesting and on-topic matter, for this particular case where both, the VGA and the 15khz monitors will stay in use, should I have both connected during the installation process, the former with the HDMI-to-VGA converter, the latter through the analog output or is it better to follow the Eiusdemmodi tutorial as is to later do the dual display thing?