metaleggman wrote on 2020-06-11, 03:30:

Hi all, […]
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Hi all,

I recently unearthed my old Packard Bell CRT and hooked it up to my modern gaming rig. It's 24 years old and surprisingly still works great! We got it with our old Packard Bell machine that ran 3.11 (not sure if it was a 486 or pentium or what). I've been able to play it just fine with Windows titles like Diablo, Outlaws, and games on ScummVM without any issues so far. I played Heroes of Might and Magic on it just fine using the gog-included version of dosbox. But then I got the wise idea to try DosBox ECE, and the only way to get it to work in fullscreen with the image actually filling the screen is by using scaling. But...it's a VGA CRT, I would like to think I wouldn't need to scale the original resolution images. When using normal2x scaling (which I presume I was using on the gog version of HoMM) it looked funky in the dos prompt and in game while playing Dark Forces. Everything looked all...poorly scaled.

Is the idea of using a CRT for dosbox and having dosbox output something akin to an actual vga resolution more or less a pipedream, and that I might as well go and dig out my old PCs if I really care that much? Or are there some settings that I can use that should get me even 90%, hell, 75% as good as if I was just hooking up this CRT to my old gear?

The monitor is a white Packard Bell 1511SL (no, not the rare black one sadly)
My rig has a GTX 2060 in it, running Windows 10
I'm using a monoprice HDMI to VGA adapter

The odd thing is if I mess with nvidia custom resolutions, I can get working picture output of, say, 640x480 @60hz to the CRT monitor, but she seems happier at 800x600 or 1024x768 (windows claims this is the native resolution). I'm guessing I'd need to calculate some custom timings at a resolution like 640x480 at a given refresh rate to get her happy with it. In doing some digging on this topic, that's one of the other weird things I've learned about all these DOS games, they apparently run at 70hz sometimes? And while I knew about the whole 320x200 resolution issue, with everything doubled, it's calling into question how in God's name I could get some good looking output from this thing haha. If I overlooked some awesome guides or threads on this subject, please, direct me to them.

Any and all help is appreciated, and to be frank, if I can just get help figuring out what the possibly *best* settings for this would be, even if it's not perfect, I'll be happy with that too. I've jumped into the conf file and played around, but sadly, I'm still coming up without much.

Windows' claim as to the native resolution of the monitor is likely based on its interpretation of your HDMI to VGA converter . CRTs do not have a native resolution .

Most VGA DOS games run at 320x200 (line doubled by the VGA card to 640x400 ) @ 70Hz

To get the best results (closest to an actual older PC with actual VGA card) on a CRT for those games, you would need to be able to define a custom resolution of 640x400 @70Hz in the Nvidia drivers .

Some potential issues :

a) Does your Monoprice HDMI to VGA converter accept 70Hz for any resolution, especially 640x400 ?
b) Does your Monoprice HDMI to VGA converter convert everything to 60Hz ?
c) Does your Monoprice HDMI to VGA converter do forced scaling to another resolution ?
d) Will the Nvidia driver even let you configure a 640x400 70Hz resolution (I doubt that CRT will properly handle an integer multiple of 640x400 , like 1280x800).

In the worst case scenario, you will probably have to settle for 640x480 at 60Hz or 800x600 at 60 Hz, whichever looks best on your setup .

As For the DOSBOX version, you would preferably want a version that does pixel-perfect rendering (possibly an SVN build) and set it to no scaling . I will let someone with more knowledge on that specific matter chime in .

EDIT: Finding an HDMI to VGA converter that supports 70Hz in and out will likely be a challenge . You may want to forsake that aspect and live with 60Hz .

darry wrote on 2020-06-11, 05:50:

Windows' claim as to the native resolution of the monitor is likely based on its interpretation of your HDMI to VGA converter . […]
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metaleggman wrote on 2020-06-11, 03:30:

Hi all, […]
Show full quote

Hi all,

I recently unearthed my old Packard Bell CRT and hooked it up to my modern gaming rig. It's 24 years old and surprisingly still works great! We got it with our old Packard Bell machine that ran 3.11 (not sure if it was a 486 or pentium or what). I've been able to play it just fine with Windows titles like Diablo, Outlaws, and games on ScummVM without any issues so far. I played Heroes of Might and Magic on it just fine using the gog-included version of dosbox. But then I got the wise idea to try DosBox ECE, and the only way to get it to work in fullscreen with the image actually filling the screen is by using scaling. But...it's a VGA CRT, I would like to think I wouldn't need to scale the original resolution images. When using normal2x scaling (which I presume I was using on the gog version of HoMM) it looked funky in the dos prompt and in game while playing Dark Forces. Everything looked all...poorly scaled.

Is the idea of using a CRT for dosbox and having dosbox output something akin to an actual vga resolution more or less a pipedream, and that I might as well go and dig out my old PCs if I really care that much? Or are there some settings that I can use that should get me even 90%, hell, 75% as good as if I was just hooking up this CRT to my old gear?

The monitor is a white Packard Bell 1511SL (no, not the rare black one sadly)
My rig has a GTX 2060 in it, running Windows 10
I'm using a monoprice HDMI to VGA adapter

The odd thing is if I mess with nvidia custom resolutions, I can get working picture output of, say, 640x480 @60hz to the CRT monitor, but she seems happier at 800x600 or 1024x768 (windows claims this is the native resolution). I'm guessing I'd need to calculate some custom timings at a resolution like 640x480 at a given refresh rate to get her happy with it. In doing some digging on this topic, that's one of the other weird things I've learned about all these DOS games, they apparently run at 70hz sometimes? And while I knew about the whole 320x200 resolution issue, with everything doubled, it's calling into question how in God's name I could get some good looking output from this thing haha. If I overlooked some awesome guides or threads on this subject, please, direct me to them.

Any and all help is appreciated, and to be frank, if I can just get help figuring out what the possibly *best* settings for this would be, even if it's not perfect, I'll be happy with that too. I've jumped into the conf file and played around, but sadly, I'm still coming up without much.

Windows' claim as to the native resolution of the monitor is likely based on its interpretation of your HDMI to VGA converter . CRTs do not have a native resolution .

Most VGA DOS games run at 320x200 (line doubled by the VGA card to 640x400 ) @ 70Hz

To get the best results (closest to an actual older PC with actual VGA card) on a CRT for those games, you would need to be able to define a custom resolution of 640x400 @70Hz in the Nvidia drivers .

Some potential issues :

a) Does your Monoprice HDMI to VGA converter accept 70Hz for any resolution, especially 640x400 ?
b) Does your Monoprice HDMI to VGA converter convert everything to 60Hz ?
c) Does your Monoprice HDMI to VGA converter do forced scaling to another resolution ?
d) Will the Nvidia driver even let you configure a 640x400 70Hz resolution (I doubt that CRT will properly handle an integer multiple of 640x400 , like 1280x800).

In the worst case scenario, you will probably have to settle for 640x480 at 60Hz or 800x600 at 60 Hz, whichever looks best on your setup .

As For the DOSBOX version, you would preferably want a version that does pixel-perfect rendering (possibly an SVN build) and set it to no scaling . I will let someone with more knowledge on that specific matter chime in .

EDIT: Finding an HDMI to VGA converter that supports 70Hz in and out will likely be a challenge . You may want to forsake that aspect and live with 60Hz .

Sorry for the late reply. Thanks for the handy info and questions to consider. Good news! It seems to work just fine now! I use a custom resolution of 640x400 @70Hz through nvidia control panel, and used the following:

1fullscreen          = false
2fullborderless      = false
3fulldouble          = false
4fullresolution      = 640x400
5windowresolution    = original
6output              = ddraw
7
8
9frameskip = 0
10aspect    = false
11scaler    = none

Everything looks great now, and since switching to ddraw, there's no more weird screentearing either. There's probably some issue I'm not noticing, and I can't tell what the monitor thinks its displaying (my newer Sony monitor, if I get it fixed, had an OSD, this just has buttons that light up). And yeah, I think the most this monitor can really push is 1152x864@60hz. Hopefully if I ever get the Sony monitor fixed, I could get something nice going for retro Windows games with voodoo graphics, like 1280 x 800 @80hz or something haha.

Thanks for the help! I hope if anyone else has similar issues, this might help them.

Note that DOSBox nearly always runs its emulated graphics hardware at 70Hz (except when something manually configures the crtc registers), so you get framerate jitter if the actual display is running at a different rate. In some cases you also get bad slowdowns/stuttering if the display rate is lower and the graphics driver doesn't obey DOSBox's request to disable vsync.

jmarsh wrote on 2020-06-21, 09:57:

Note that DOSBox nearly always runs its emulated graphics hardware at 70Hz (except when something manually configures the crtc registers), so you get framerate jitter if the actual display is running at a different rate. In some cases you also get bad slowdowns/stuttering if the display rate is lower and the graphics driver doesn't obey DOSBox's request to disable vsync.

Good to know! This might be why the game runs perfectly using directdraw, but is all weird and tears when I tried using opengl (can't quite remember how surface worked).

darry wrote on 2020-06-11, 05:50:

Windows' claim as to the native resolution of the monitor is likely based on its interpretation of your HDMI to VGA converter . CRTs do not have a native resolution .

[OffTopic] Isn't there some upper limit which is caused by the number of red/green/blue zones on the CRT mask? At least in non-monochrome CRTs?

junglemontana wrote on 2020-07-17, 07:33:

darry wrote on 2020-06-11, 05:50:

Windows' claim as to the native resolution of the monitor is likely based on its interpretation of your HDMI to VGA converter . CRTs do not have a native resolution .

[OffTopic] Isn't there some upper limit which is caused by the number of red/green/blue zones on the CRT mask? At least in non-monochrome CRTs?

a) If you increase the resolution far enough, you will get to a point where the image is fuzzy/soft, due to the CRT's dot pitch . https://computer.howstuffworks.com/monitor8.htm

b) Another limit on resolution is due to the maximum horizontal and vertical scanning rates that a CRT can handle .

Depending on which is hit first, a) imposes a practical limit on input resolution and b) an absolute one . Neither of those is a "native resolution", just a maximum one .

Yeah, that's what I thought... How about monochrome displays? Were they ever manufactured with uniform (non-pixelated) phosphor screen?

edit: Probably yes, for example in old analog oscilloscopes. But how about computer monitors?