1600 x 1200 is high enough that DVI speed limit is reached, which is 165MHz. This is why 60Hz is the max is majority of implementations as it leads to 162MHz pixel clock, right at the very edge of official specs. This is assuming single link, dual link should allow more (double) but I don't know how many such implementations exist.

While I don't have a suggestion for the monitor, I will say that you actually want 60 Hz for playing games from the early to mid 2000s.

The reason is that most of them are multi platform titles which were designed for running on consoles connected to 60 Hz TVs. If you set your refresh rate higher than that, you get weird engine behavior which results in bugs and glitches. A prominent example of this is Star Wars: Knights of the Old Republic (see here). You can find many more issues like this on the PC Gaming Wiki.

See LCD Screen for Real Hardware Early DOS Gaming (320x200)

If the reason you want 70Hz is because you're planning on showing perfectly scaled 320x200 DOS games, you're out of luck. Monitors perform incorrect scaling for that resolution and 4:3 ones don't support 70Hz, as far as I'm aware.

Also note that the text about the 2007fp only pertains its supported input frequencies, it always shows 60Hz.

I still have my old Philips Brilliance 200P6 4:3 LCD monitor (VGA/DVI).
Works with virtually everything, 60/70/75 Hz, even manages 50Hz with old 8-bit micros and fpga emulators.
Includes RCA/S-Video composite inputs, which probably explains why it can handle 50Hz VGA too.

Except maybe some VESA modes whose timings were made standard after the year 2006, the breaking line seems to be at VESA DMT-1.11 standard. The 1280x800 is not there in DMT-1.10, and my monitor does not support it, interpreting the input as 1280x768.

An LCD monitor that accepts 70Hz input at a given resolution will not necessarily display at 70Hz. A monitor might accept 70Hz, but display at 60Hz (discarding one out of every 7 frames).

This is especially true of older (4:3 ) LCD monitors .

This has been discussed at length in a few previous threads. Searching for 70Hz and LCD should yield some results. When I got a moment, I will try to link a few examples.

That being said, IMHO, the best way to get 70Hz to actually display at 70Hz on an LCD at 1600x1200 is to use a modern 1920x1200 display that has an explicit 4:3 mode and a panel that is capable of 70Hz. You will get black bars on each side, but a 1600x1200 (4:3) 70Hz picture in the middle.

EDIT : Corrected typos/oversights

General rule for old displays:
Majority of 1280x1024 panels support true 75 Hz.
Almost all (if not all) 1600x1200 known panels do not support true 75 Hz.
Some 1680x1050 panels (Dell and NEC 20/22inch displays, for example) support true 75 Hz.

1600x1200 panels are fine if you use DOSBOX. And to be fair, modern 120/144 Hz LCD displays are much more closer to CRT experience, especially if black frame insertion is used.

The Serpent Rider wrote on 2022-09-07, 15:48:

General rule for old displays: Majority of 1280x1024 panels support true 75 Hz. Almost all (if not all) 1600x1200 known panels d […]
Show full quote

General rule for old displays:
Majority of 1280x1024 panels support true 75 Hz.
Almost all (if not all) 1600x1200 known panels do not support true 75 Hz.
Some 1680x1050 panels (Dell and NEC 20/22inch displays, for example) support true 75 Hz.

1600x1200 panels are fine if you use DOSBOX.

AFAIK, most if not all older IPS panels, regardless of size/aspect/resolution are limited to 60Hz, it is only relatively recently (not sure of cut off time but maybe somewhere in last 10 or so years?) that IPS panels capable of >60Hz starting becaming available . Please correct me if I am wrong .

most if not all older IPS panels

Can't say for IPS panels, but few very old xVA panels I had experience with happily accepted 75 Hz, maybe because it fits into single link DVI spec. I doubt IPS counterparts had drastically different scalers. And like I said, Dell 2209WA (IPS) will work at 75 Hz, with some headroom for further overclocking around +/- 80 Hz. That display is like what, 12-13 years old now?

Thanks for all the replies, super informative!

> 1600 x 1200 is high enough that DVI speed limit is reached, which is 165MHz

That is true for CVT timings, but for CVT-RBv1 (Reduced Blanking) and CVT-RBv2 timings, they do fit within the link speed budget. See https://tomverbeure.github.io/video_timings_calculator (type in 1600x1200@70 there)

However, checking out the specs at https://glenwing.github.io/docs/VESA-CVT-1.2.pdf , I am unsure when the RBv1 addition would have come about. RBv2 came about in Feb 2013.

The DMT standard from https://ez.analog.com/cfs-filesystemfile/__ke … 869585122834374 lists in ChangeLog that in 2007 Reduced Blanking was added as a concept for 1600x1200 resolution, and lists that resolution all the way up to 120hz.

So it might be possible that some DVI displays could support a 1600x1200@70hz at Reduced Blanking.

I can flexibly generate either DMT, CVT, CVT-RBv1 or CVT-RBv2, so don't want to rule out anything based on this issue.

> Also note that the text about the 2007fp only pertains its supported input frequencies, it always shows 60Hz.
> An LCD monitor that accepts 70Hz input at a given resolution will not necessarily display at 70Hz. A monitor might accept 70Hz, but display at 60Hz (discarding one out of every 7 frames).

That's a great gotcha to know (although super disappointing) that there are displays are actually doing frameskip to decimate > 60hz inputs down to 60hz for their panels. I'll have to keep an eye out for this by doing some practical tests.

> I still have my old Philips Brilliance 200P6 4:3 LCD monitor (VGA/DVI).

Thanks for this suggestion! Quick search unfortunately does not find hits on eBay so that I could get this in for testing with ease, but I'll keep an eye out for this model.

> That being said, IMHO, the best way to get 70Hz to actually display at 70Hz on an LCD at 1600x1200 is to use a modern 1920x1200 display that has an explicit 4:3 mode and a panel that is capable of 70Hz. You will get black bars on each side, but a 1600x1200 (4:3) 70Hz picture in the middle.
> Almost all (if not all) 1600x1200 known panels do not support true 75 Hz.

I suppose I'll go and get that ASUS ProArt 248QV for testing, and see how well that works.

The reason I am looking also for older displays is that I am also generating smaller resolutions, like 320x240, and not many newer HDMI displays want to sync to such small resolutions (e.g. my BenQ BL3201PT does not much like anything smaller than 640x480).

clb wrote:

some DVI displays could support a 1600x1200@70hz at Reduced Blanking.

What you generate on input doesn't matter much, because you can't work with scaler directly. And 1600x1200 panels can't generate smooth 70 Hz on any input resolution due to that.

clb wrote on 2022-09-09, 08:51:

I suppose I'll go and get that ASUS ProArt 248QV for testing, and see how well that works.

Coincidently I just purchased this exact monitor for using with Windows XP on both 16:10 and 4:3 resolutions.

I've already had a bit of challenge getting both the 75 Hz to run in conjunction with 4:3 resolution. I've had to use a HDMI cable plus a HDMI->DisplayPort adapter (to the GPU) in order for both of those functions to work simultaneously. HDMI by itself only resulted in 60 Hz, and the Displayport by itself didn't allow 4:3 mode.

Haven't tried it with VGA yet or in DOS.

The reason I am looking also for older displays is that I am also generating smaller resolutions, like 320x240, and not many newer HDMI displays want to sync to such small resolutions (e.g. my BenQ BL3201PT does not much like anything smaller than 640x480).

I own and have tested various LCD displays in DOS. I find that newer LCDs generally don't play nice with DOS resolutions (text mode or lower VGA resolutions).

The one I've had the most success with so far is the HP LP2065 (1600x1200 20" monitor), which I'm currently using on my Win 98 machine and have used with a few DOS games like Doom and Duke 3D. It's not perfect, but is more usable than most I've tried.

CRT is still the best solution for classic DOS usage (text mode and VGA/etc resolutions).

I don't have good experience with HP LP2065. I did't try it much in DOS - but in windows if I set anything other than 60 Hz, it stutters like crazy.

clb wrote on 2022-09-09, 08:51:

Thanks for all the replies, super informative! […]
Show full quote

Thanks for all the replies, super informative!

> 1600 x 1200 is high enough that DVI speed limit is reached, which is 165MHz

That is true for CVT timings, but for CVT-RBv1 (Reduced Blanking) and CVT-RBv2 timings, they do fit within the link speed budget. See https://tomverbeure.github.io/video_timings_calculator (type in 1600x1200@70 there)

However, checking out the specs at https://glenwing.github.io/docs/VESA-CVT-1.2.pdf , I am unsure when the RBv1 addition would have come about. RBv2 came about in Feb 2013.

The DMT standard from https://ez.analog.com/cfs-filesystemfile/__ke … 869585122834374 lists in ChangeLog that in 2007 Reduced Blanking was added as a concept for 1600x1200 resolution, and lists that resolution all the way up to 120hz.

So it might be possible that some DVI displays could support a 1600x1200@70hz at Reduced Blanking.

I can flexibly generate either DMT, CVT, CVT-RBv1 or CVT-RBv2, so don't want to rule out anything based on this issue.

> Also note that the text about the 2007fp only pertains its supported input frequencies, it always shows 60Hz.
> An LCD monitor that accepts 70Hz input at a given resolution will not necessarily display at 70Hz. A monitor might accept 70Hz, but display at 60Hz (discarding one out of every 7 frames).

That's a great gotcha to know (although super disappointing) that there are displays are actually doing frameskip to decimate > 60hz inputs down to 60hz for their panels. I'll have to keep an eye out for this by doing some practical tests.

> I still have my old Philips Brilliance 200P6 4:3 LCD monitor (VGA/DVI).

Thanks for this suggestion! Quick search unfortunately does not find hits on eBay so that I could get this in for testing with ease, but I'll keep an eye out for this model.

> That being said, IMHO, the best way to get 70Hz to actually display at 70Hz on an LCD at 1600x1200 is to use a modern 1920x1200 display that has an explicit 4:3 mode and a panel that is capable of 70Hz. You will get black bars on each side, but a 1600x1200 (4:3) 70Hz picture in the middle.
> Almost all (if not all) 1600x1200 known panels do not support true 75 Hz.

I suppose I'll go and get that ASUS ProArt 248QV for testing, and see how well that works.

The reason I am looking also for older displays is that I am also generating smaller resolutions, like 320x240, and not many newer HDMI displays want to sync to such small resolutions (e.g. my BenQ BL3201PT does not much like anything smaller than 640x480).

Careful, the ASUS ProArt 248QV (aka PA248QV ) is not suitable to baremetal DOS gaming at 320x200 (4:3 image ) without the use of an actual scaler like the Extron RGB-DVI300(A) or Extron RGB-HDMI-300 (OSSC will not help, as it is not a scaler)

Excerpt from : Re: Purchasing a 4:3 LCD for DOS/DOSBOX/MISTER/OSSC games? :

The PA248QV looks interesting , but according to https://dlcdnets.asus.com/pub/ASUS/LCD%20Moni … 8QV_English.pdf , page 3-5 says

1Aspect Control: Adjusts the aspect ratio to full, 4:3, or OverScan.
24:3 is only available when input source is in 4:3 format. OverScan is only
3available for the HDMI input source.

which gives the impression that this is not a true 4:3 mode, but possibly a so called "aspect" mode (where the display essentially tries to guess at what should be displayed as 4:3) and that 320x200 (640x400) might not be displayed as 4:3 . I could be wrong, of course, but the language used in the manual raises my suspicions on that front .
EDIT : Looks like my fears about the PA248QV's unability to do 320x200 (640x400) at 4:3 aspect ratio are confirmed here --> https://www.reddit.com/r/dosgaming/comments/h … iably_force_43/

1With this new found idea I purchased an ASUS PA248QV, a 1920x1200 75Hz display with VGA input and a force 4:3 option. Sounds great! What's not to like? Well, it can force 4:3 unless it believes it's being fed a 16:10 resolution. Guess what ratio 320x200 truly is? Yeah.

I did get the ASUS ProArt 248QV, and I can confirm the abovementioned behavior: if I feed it an input HDMI signal that is not 4:3, then the display will refuse to scale it to 4:3 as well. I.e. if I input a 640x400 signal, the display will have the "Aspect Control" option in the menu grayed out.

Boo indeed.

Also, if I input a 320x200 or 320x240 or e.g. a 320x400 signal, then the display does not want to sync.

It will sync to 640x350, 640x400 and 640x480, both at 60hz and 70hz.

However not all is lost: I am persistently working to still tame this beast. 😀

Well now that I am reading this thread - you might have explained a strange phenomenon I ran into a bit earlier.

I have a few Samsung 214T monitors stockpiled as it's 4:3 with composite and S-video inputs, perfect for very old machines. I watched C64 demos on it and I was satisfied. Yet when I tried to play the PC version of Pinball Fantasies I saw strange jerkiness and tearing so I had to switch the monitors.

Well I've never experienced it on my Benq 2470 - but that's wide and I wanted to see it in 4:3 at last. Good news is, I didn't get the same tearing on my Fujitsu-Siemens P20-2S, it played smooth and nice.

I don't know for sure if it means that it does perfect 70Hz, AFAIK Pinball fantasies doesn't even run at 320x200 - it was still strange.

Edit. I did some further testing with more games and demos. Heretic was, for example, quite okay on both monitors - not perfect though. The 1996 demo Dive proved to be the right tool to diagnose them as it has 1-frame- long background flashes in 320x200/70Hz mode.

Samsung 214T - Tearing galore. Maybe lost flashes too.
FuSi P20-2s - No tearing but it skipped some frames. Maybe every 7th...
Benq 2470 - It had every single frame, perfectly smooth experience - but it didn't even let me select 'aspect' in 320x200/70Hz. So I was stuck with everything resized and distorted to 16:9.