PhilsComputerLab wrote:

720 x 400 is what all my LCDs show in the menu. […]
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720 x 400 is what all my LCDs show in the menu.

A real shame that aspect ratio controls don't work for you 🙁

Is there maybe a firmware update? Do contact DELL and see what they say.

I guess at 640 x 480 and higher it will work? My AOC screens also have this behaviour.

Hi Phil.

Huge fan of your YouTube show, by the way. It's what got me back into reliving my PC past. I just wish your show wasn't so damn expensive to watch. 😄

Regarding the monitor, I've checked the firmware, and it's the newest version - "05". I just don't understand how dr_st could get it to work on his monitor but I can't?
Thanks for clearing the 720x400 nonsense up, though. At least I know that's not the culprit.
I have also just tried Duke 3D Atomic Edition in various resolutions, and VESA modes are scaled to the correct aspect ratio on the U2410. Anything below that is a problem, though. And since most DOS games up to the mid-nineties were 320x200 or other low-res permutations this really bugs the hell out of me.

Imperious wrote:

I have a Dell U2412, when setting either 4:3 or 5:4 (native 16:10) it forces that aspect ratio no matter what resolution is put into it.
I haven't used the Display port but VGA and DVI works well.

Good to know. Now I wish I hadn't followed the U2410 recommendation from earlier in the thread. It'll be a while before I'll be able to afford another monitor.

od1n wrote:

Oh, and when I'm checking the "Info" tab in the U2410s menu while attached to my DOS system, it says that it's receiving a 720x400 signal (both when displaying the DOS prompt or a 320x200 game like Doom). It makes no earthly sense. Unless my graphics cards have gone completely rogue and are choosing to upscale their outputs, the info tab has to be lying.

Actually, I am not sure it lies. In fact it may be the culprit.

Following your report, I decided to check for myself. I do not have a real DOS machine at the moment, so I used the BIOS and my Windows Millennium setup CD as the reference. Here are my findings and conclusions thus far:

• Video cards do upscale their DOS outputs. Each video card does it differently.
• My primary desktop has a GTX660. This one upscales DOS/BIOS to a full 1920x1200 (probably just detects the maximum resolution of the monitor, at least via DVI). With this video card, Aspect, 1:1 and Fill look exactly the same, because the monitor receives its full 1920x1200 resolution.
• I tried with a Thinkpad X220 and its DisplayPort output. This one apparently upscales DOS to 640x480 (monitor shows it as "480p"). With this laptop, behavior is exactly as you would expect. "Fill" stretches to the full screen, "Aspect" stretches top and bottom, leaving black bars on the sides, and "1:1" displays the screen in a small centered window.

This is somewhat consistent with your findings. 320x200 is a 8:5 (16:10) resolution. 720x400 is even 9:5 which is almost exactly 16:9.

However, where it is not consistent, is that you say that the settings have no effect. I would expect that if you try 1:1, you would see a small centered window of 720x400. But you don't, so maybe something else is going on. Perhaps VGA behaves differently.

Edit: Did some more tests with the U2410.

• Connecting the Thinkpad X220 via VGA still outputs 640x480. The monitor detects it correctly, and aspect/1:1 work as expected.
• Connecting the desktop with the GTX660 via VGA would be an interesting test, but the card has no VGA output, and I seem to have misplaced my DVI->VGA adapter. 🙁

Also did a few more tests with another laptop (Thinkpad T60 with ATI) connected to a different monitor (DELL 2209WA, 1680x1050, which only has "Fill" and "4:3" options).

• In BIOS: VGA outputs 640x480, DVI outputs 1680x1050.
• In Windows (tested DVI only): The GPU has a scaling feature. When enabled, DVI always outputs 1680x1050, after the GPU has scaled it according to settings (which can be either 1:1, aspect or stretch). When scaling is disabled, the DVI outputs whatever selected, but only a handful of resolutions (it can do 640x480, 1024x768, and 1280x1024, and of course 1680x1050, but not others). This can be a configuration limitation rather than actual limitation of the GPU, but I am not certain.
• Given the fact that DVI shows 1680x1050 in the BIOS, I imagine that GPU scaling is enabled in the pre-boot environment by default.

The (sad) conclusion from all this is that "Aspect" setting on a monitor is not good enough if you care about DOS, because video cards cannot be trusted to output the correct expected aspect ratios. Ironically, a more limited setting which forces 4:3 / 5:4 / whatever, would be better in this case. I would go as far as to say that for DOS, most of it is really 4:3, you should just find a monitor that has a 4:3 setting.

I am sorry that I misled you to buy a monitor, which, good as it may be, is not suited for your particular task. 😢

One course of action that can get you out of this pickle, is locating a person who would trade you their U2412M for the U2410. Since U2410 is technically a better monitor, with more inputs and features, you may just find someone interested in such a trade. Or you can just sell the U2410 and get a U2412M. Since the U2410 cost much more than the U2412M when they were both new, it may be that you will be able to break even with this.

I have the U2410 as well. The large number of inputs makes it invaluable for running many machines each on a different input.

Playing my voodoo5 through the VGA connection is fine in Windows 98: "aspect" fits the screen vertically with black bars at the sides , "fill" stretches to fill the screen entirely, "1:1" gives a centred display.

But in DOS mode, although "1:1" still gives the small centred display [looks like 720x400?], both "fill" and "aspect" fill the screen horizontally, the only difference is the vertical stretch which is applied in "fill" but not "aspect" ["aspect" does not fill the screen vertically].

When you use DVI, it uses what's called EDID, the GPU will negotiate a resolution with the monitor. Nvidia does this well. Other cards just output 1280 x 1024 or do other odd things.

You can override this with an EDID emulator, StarTech sells one, and "lock in" 1024 x 768 for example. This is great for capturing...

dr_st wrote:

Actually, I am not sure it lies. In fact it may be the culprit. […]
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od1n wrote:

Oh, and when I'm checking the "Info" tab in the U2410s menu while attached to my DOS system, it says that it's receiving a 720x400 signal (both when displaying the DOS prompt or a 320x200 game like Doom). It makes no earthly sense. Unless my graphics cards have gone completely rogue and are choosing to upscale their outputs, the info tab has to be lying.

Actually, I am not sure it lies. In fact it may be the culprit.

Following your report, I decided to check for myself. I do not have a real DOS machine at the moment, so I used the BIOS and my Windows Millennium setup CD as the reference. Here are my findings and conclusions thus far:

• Video cards do upscale their DOS outputs. Each video card does it differently.
• My primary desktop has a GTX660. This one upscales DOS/BIOS to a full 1920x1200 (probably just detects the maximum resolution of the monitor, at least via DVI). With this video card, Aspect, 1:1 and Fill look exactly the same, because the monitor receives its full 1920x1200 resolution.
• I tried with a Thinkpad X220 and its DisplayPort output. This one apparently upscales DOS to 640x480 (monitor shows it as "480p"). With this laptop, behavior is exactly as you would expect. "Fill" stretches to the full screen, "Aspect" stretches top and bottom, leaving black bars on the sides, and "1:1" displays the screen in a small centered window.

Interesting. I have a handful more cards lying around. I will try them out today and see what they output.

This is somewhat consistent with your findings. 320x200 is a 8:5 (16:10) resolution. 720x400 is even 9:5 which is almost exactly 16:9.

However, where it is not consistent, is that you say that the settings have no effect. I would expect that if you try 1:1, you would see a small centered window of 720x400. But you don't, so maybe something else is going on. Perhaps VGA behaves differently.

Oh, sure. Something does happen. It does indeed scale the image down 1:1 with square pixels like expected. I just meant that I wasn't able to the get the "Aspect" setting working no matter how many times I cycled through them. Sorry for not being clear.

Edit: Did some more tests with the U2410.

<snip>
I think modern cards on modern machines are a bad comparison since, just like your findings prove, most of them can't actually output any lower than 640x480 and any lower or offbeat resolutions of the past are simply scaled to the nearest mode that the cards can resolve.
The reason for my purchase of the U2410 was to get a monitor that actually could properly resolve resolutions from a real DOS machine with common late 90's hardware. And apparently it can't.

The (sad) conclusion from all this is that "Aspect" setting on a monitor is not good enough if you care about DOS, because video cards cannot be trusted to output the correct expected aspect ratios. Ironically, a more limited setting which forces 4:3 / 5:4 / whatever, would be better in this case. I would go as far as to say that for DOS, most of it is really 4:3, you should just find a monitor that has a 4:3 setting.

Yeah, that's my conclusion too.

I am sorry that I misled you to buy a monitor, which, good as it may be, is not suited for your particular task. 😢

Hey - chin up, man. If I had just a bit of sense, I should have asked you if your tests were carried out on an actual DOS machine before I went out and purchased it. It's still a good monitor* and it fits in nicely with my existing Dell 2407WFP and 2408WFP (which both happen to be even worse at scaling 4:3 content if you can believe that). I'll just have to save up for a U2412M (incredibly, none of the other monitors greenlighted for proper 4:3 low-res scaling in this thread can be sourced within 500 kilometers of where I live).
* The colour accuracy does appeal to me since I do graphics and interaction design for a living.

Either way, I'm really glad you took the time to re-test and respond to my post. At least this might save someone else from picking up this particular monitor for their DOS system.

One course of action that can get you out of this pickle, is locating a person who would trade you their U2412M for the U2410. Since U2410 is technically a better monitor, with more inputs and features, you may just find someone interested in such a trade. Or you can just sell the U2410 and get a U2412M. Since the U2410 cost much more than the U2412M when they were both new, it may be that you will be able to break even with this.

You'd think that would be the case given the original list prices of the two monitors, but here in Denmark it's actually the other way around. U2412Ms cost twice as much used as U2410s. I'm really not sure why. I would surmise that the owners simply can't remember (or don't care about) the original list price and simply price them based on age alone.

od1n wrote:

The reason for my purchase of the U2410 was to get a monitor that actually could properly resolve resolutions from a real DOS machine with common late 90's hardware. And apparently it can't.

It's not that it can't. It's just that we've been going about it the wrong way. Common DOS resolutions are not 4:3. Both 320x200 and 720x400 are widescreen resolutions. But old CRTs were 4:3, and so they distorted these resolutions to have non-square pixels. And because everyone knew that to be the case, they adjusted the characters and pictures to compensate for that. However, LCDs have square pixels. So when you output the raw 320x200 or 720x400 to a monitor that knows how to preserve aspect, it does exactly what it is told to do - preserves the aspect, which causes the content (that was originally created with compensation for non-square pixels in mind) to appear stretched.

Some video cards try to be clever and compensate for that, so they output 640x480, like the X220 I tested with. But then it kind of looks like crap, because (that's my assumption, at least) the default fonts used in DOS mode are not designed for this, and text appears smeared. At least this is how it looked when I tested. In the laptop's BIOS, though, everything is sharp and crisp, probably because they specifically selected the font to look good with the resolution they output.

So yeah, I would emphasize again: for DOS you should just find a monitor that has a forced 4:3 setting.

od1n wrote:

Hey - chin up, man. If I had just a bit of sense, I should have asked you if your tests were carried out on an actual DOS machine before I went out and purchased it.

It probably would not have helped you. 🙁 I would have told you that I had used an actual DOS machine, because I did. It just so happened that I ran my tests on the same Thinkpad X220, which as we know, does output a 4:3 resolution in DOS. You would have had to ask if I specifically used an old machine with actual period-correct hardware, and to that I would have replied "no", simply because I do not have such a machine in the same house where the U2410 is located. 😀

od1n wrote:

Either way, I'm really glad you took the time to re-test and respond to my post. At least this might save someone else from picking up this particular monitor for their DOS system.

Most certainly. Thank you for reporting this. I actually went back and edited my original post with clarifications, and a link to this discussion, so that folks who happen to randomly stumble only on that post, are more careful. 😀

od1n wrote:

You'd think that would be the case given the original list prices of the two monitors, but here in Denmark it's actually the other way around. U2412Ms cost twice as much used as U2410s. I'm really not sure why. I would surmise that the owners simply can't remember (or don't care about) the original list price and simply price them based on age alone.

Wow. Well, better save up for the U3011, then. It has 1:1, 4:3, 16:9, and Aspect modes. Try to convince a potential seller to give it up for less than the U2412M, simply because it's older. 😜

dr_st wrote:

od1n wrote:

The reason for my purchase of the U2410 was to get a monitor that actually could properly resolve resolutions from a real DOS machine with common late 90's hardware. And apparently it can't.

It's not that it can't. It's just that we've been going about it the wrong way. Common DOS resolutions are not 4:3. Both 320x200 and 720x400 are widescreen resolutions. But old CRTs were 4:3, and so they distorted these resolutions to have non-square pixels. And because everyone knew that to be the case, they adjusted the characters and pictures to compensate for that. However, LCDs have square pixels. So when you output the raw 320x200 or 720x400 to a monitor that knows how to preserve aspect, it does exactly what it is told to do - preserves the aspect, which causes the content (that was originally created with compensation for non-square pixels in mind) to appear stretched.

Yep. It makes perfect sense once you start to consider what "preserve aspect" actually means. I just took it for granted that the implementation would be smarter and properly compensate for those resolutions that were never meant to be displayed verbatim (i.e. square pixels) back when they were commonplace - like 320x200. I mean, no one in their right mind would scale a resolution like 720x576 for square pixels either. Some resolutions just come with inherent history. But the "aspect" feature on those DELLs certainly do exactly what it says on the tin.

So yeah, I would emphasize again: for DOS you should just find a monitor that has a forced 4:3 setting.

Yeah. Lesson learned. That's the only way forward.

od1n wrote:

Either way, I'm really glad you took the time to re-test and respond to my post. At least this might save someone else from picking up this particular monitor for their DOS system.

Most certainly. Thank you for reporting this. I actually went back and edited my original post with clarifications, and a link to this discussion, so that folks who happen to randomly stumble only on that post, are more careful. 😀

I noticed. Thanks for that. 😀

od1n wrote:

You'd think that would be the case given the original list prices of the two monitors, but here in Denmark it's actually the other way around. U2412Ms cost twice as much used as U2410s. I'm really not sure why. I would surmise that the owners simply can't remember (or don't care about) the original list price and simply price them based on age alone.

Wow. Well, better save up for the U3011, then. It has 1:1, 4:3, 16:9, and Aspect modes. Try to convince a potential seller to give it up for less than the U2412M, simply because it's older. 😜

Hah! Yeah - and further extrapolating on that logic, I should be able to pick up 20" Sony BVMs for a song. 😀

There are three aspects to be aware of with LCD:
1. VGA input.
2. Force 4:3 aspect ratio in scaler.
3. Non-locked refresh rate for 70Hz modes.

Less and less monitors come with VGA input.
Most IPS are locked to 60Hz or come without a VGA input.
Many new value monitors still come with a VGA input but lack a quality scaler to force 4:3.

I have the ASUS VN279Q for that, it has a VA panel which has excellent color reproduction and a 3000:1 contrast ration.

Benq and Samsung are brands I would lean towards.

I've got a Philips with a dedicated 4:3 button, and I know of a Benq one. My Samsung screens have an OSD option.

A great way to test is a simple boot floppt or CD with PCPlayerBench on it. It supports all sorts of resolutions.

Another way to test a VGA screen (LCD/CRT) on a modern PC with Dosbox:

Disable the GPU scaler:

Create a custom resolution: 640x400 70Hz (DMT timing):

Dosbox config:
output=opengl
fullresolution=original
aspect=false
scaler=none

My favorite game to test 70Hz text mode is Supaplex, I can clearly see if 70Hz stutters or not.

These are also the settings when I use my CRT with dosbox on a modern machine.
It switches between 640x480@60Hz and 640x400@70Hz automatically as the game requires.
It also works over DVI and DisplayPort, useful if you have a 144kHz IPS panel.

EDIT: Changed some parameters and verified the settings.

PhilsComputerLab wrote:

Benq and Samsung are brands I would lean towards.

I've got a Philips with a dedicated 4:3 button, and I know of a Benq one. My Samsung screens have an OSD option.

A great way to test is a simple boot floppt or CD with PCPlayerBench on it. It supports all sorts of resolutions.

I've been curious about the 5:4 ASUS monitor that's been featured in a number of your videos. Most recently last week's "486DX 33 MHz DOS Retro Gaming Roland MT-32 Sound Canvas" video.
Which model is that - and could you perhaps share a few words about it?

od1n wrote:

PhilsComputerLab wrote:

Benq and Samsung are brands I would lean towards.

I've got a Philips with a dedicated 4:3 button, and I know of a Benq one. My Samsung screens have an OSD option.

A great way to test is a simple boot floppt or CD with PCPlayerBench on it. It supports all sorts of resolutions.

I've been curious about the 5:4 ASUS monitor that's been featured in a number of your videos. Most recently last week's "486DX 33 MHz DOS Retro Gaming Roland MT-32 Sound Canvas" video.
Which model is that - and could you perhaps share a few words about it?

It's an Asus VB198, a fairly modern / new 19" 5:4 screen. Has VGA and DVI and a great picture. No fancy features that stand out, it's just a decent screen that works.

Dealing with an IPS that does take 70 Hz via DVI but only draws 60 Hz, I appreciate the dumber output circuitry in my Voodoo5 Mac compared to nVidia. It's preferable to me that the games' internal timing stays intact and the odd frame gets dropped at the display's end, although I'm sure there are games that look a little better forced to 60 Hz.

Hi everyone,

I am currently looking at acquiring a monitor to hook up to one or more DOS rigs with period correct hardware, to be precise a 386SX25, a P233MMX, and I'm looking at getting a K6-III+ for multi-purpose use as PhilsComputerLab has been doing.

What would be a reasonable choice of monitor that isn't made out of unobtainium that will do correct aspect ratio and correct frame rates? Ideally I'd like a 1920x1200 monitor so that the number of vertical scanlines is a nice multiple of 200, 240, 400, and 600. I'm obviously concerned about 320x200 as well as 70Hz fed from VGA d-sub input. As I've read in this thread IPS panels seem to be a problem for 70Hz on VGA input. Is that still the case or are newer panels better in this regard? Does PLS make matters even worse or is it an improvement? (I have no idea about the differences between IPS and PLS.) Or should I just go hunting for a good second hand tn panel?

I should've never thrown out my 22" Iiyama CRT... But I was moving to the other side of the world and the thing was nearly 40kg...

Cheers.

AFAIK, PLS is just Samsungs variant of IPS, these are locked to 60 Hz as well. I haven't looked for some time, but I think the Samsung 1920x1200 TN business screens were the last to fulfill all of the requirements. Which is a pity, because these are really beginning to look old compared to new LCD screens. Might be worth a try second-hand.

New displays usually lack VGA support, and those which still have a VGA connector will only recognize VESA resolutions, which means the aspect correction will not work in VGA modes (at best), or you get no picture at all (at worst).

Is there a claim that all IPS panels are locked to 60Hz? Because I think it's completely untrue. Or is it specifically about the refresh rate over VGA?

dr_st wrote:

Is there a claim that all IPS panels are locked to 60Hz? Because I think it's completely untrue. Or is it specifically about the refresh rate over VGA?

Yeah, it's specifically about the analog VGA input. I'm sure there are plenty of neat solutions for digital input.

I'd be interested to know if anyone's done any testing on 4K monitors? I would guess the refresh rates would be too low for now or otherwise be very expensive.

[edited entry: after using an older system, the results were much better. Previously I had major flickering in most DOS modes when tested with a modern system.]

Monitor: Lenovo L220x (these were made from 2007-08)
1920x1200 22" SPVA - I haven't opened it but according to web info the panel should be a Samsung SPVA, seems it was the first on the market of this size/res.

I originally tested this monitor with a GTX275 connected to the monitor's VGA input with a passive DVI->VGA adapter. That test had massive flickering issues and some noise at the top and bottom of the screen in some modes. I originally posted those results here, but now I don't think it was a monitor issue.
After I retested with a socket-7 system running a Geforce2 MX, the flickering and noise were gone.
The results below are from the socket-7 Geforce2 MX test.

Overall result:
This monitor stretches everything to full screen. It has some noticeable choppiness in 70Hz modes due to framerate conversion.

BIOS: stretched

DOS Command prompt: stretched

DOS 320 x 200 game: stretched

DOS 640 x 400 game: stretched, noticeable jerkiness might be from 70->60Hz conversion. OSD says signal is 720x400 70Hz.

DOS 640 x 480 game: stretched, might be slightly jerky as above or that could just be system's framerate performance. OSD says 640x480 60Hz. Saw one glitched frame appear after a few minutes. Saw that more often on a faster system. Since the problem seems to scale with system performance, I suspect it might not be a monitor issue but instead caused by not using VSync.

DOS 800 x 600 game: stretched, slightly jerky as above, unsure if monitor issue or system performance issue. OSD says 800x600 60.3Hz.

DOS 1024 x 786 game: stretched, OSD: 1024x768 60Hz

DOS 1280 x 1024 game: stretched, OSD 1280x1024 59.9Hz

DOS 1600 x 200 game: stretched, OSD 1600x1200 59.9Hz

Text vertical scrolling: stretched. Scrolling a bit jerky. OSD 720x400 70Hz.

Windows 640 x 480: stretched

Windows 800 x 600: stretched

Windows 1024 x 768: stretched

Windows 1280 x 1024: stretched

Windows: 1600 x 1200: stretched