ElectroSoldier wrote on 2023-11-16, 04:13:

I cant say Ive noticed that particular problem as at the resolutions I prefer it runs at 75Hz not 70Hz.

Note that this thread is about DOS games, and most of them run at 70Hz by default.

If a monitor doesn't support 70Hz without frame skipping, those games will not run smoothly.

You can use TSR to force 60 Hz for VGA mode. Some games won't like that though.

Thank you, that was a big part of my point. If a monitor does not fully support 70Hz then it is not a good choice for DOS games.
edit: bad grammar...
added: I noticed that most new monitors that do not support the older MAC modes do not properly support the 70Hz IBM and DOS modes proper either, maybe just a coincidence.. just my opinion 😀

Horun wrote on 2023-11-16, 03:13:

Yes I do believe it frame skips at 70Hz even though it supports 75Hz, like other newer ones it has only 60Hz and 75Hz as the ver […]
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darry wrote on 2023-11-15, 14:07:

I agree, with these potential caveats ( please correct me as needed): […]
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ElectroSoldier wrote on 2023-11-15, 10:18:

I can recommend a Dell 2007fpb.
It's 4:3 aspect, decent quality for the money, plenty of cheap ones about and has composite, s video inputs to go with dsub and dvi.

I just got one and it's nice.

I agree, with these potential caveats ( please correct me as needed):

a) it frameskips 70Hz into 60Hz
b) Given it's age and likelihood of heavy use, the fluorescent backlight one of these might be quite worn and dim (are there replacement kits and are they easy to install?)
c) at least some units are prone to capacitar plague era issues and I heard recapping is quite a job on these.
d) there are IPS and MVA variants, AFAICR the IPS ones were generally preferred.

Yes I do believe it frame skips at 70Hz even though it supports 75Hz, like other newer ones it has only 60Hz and 75Hz as the verticals iirc.
The Dell 1908FP also skips at 70Hz but not 60 or 75 🙁 just my observations. For some reason the true variable verticals disappeared back a decade ago or more.
Something like the older Samsung Syncmaster 930B which is fully variable from 60Hz thru 75Hz are no longer made or maybe were rare even back then...

added: which brings back that very expensive Eizo, it does not list MAC 640 x 480 @ 66.67 or MAC 832 x 624 @ 74.55 which are needed for Mac's and are not frame skipped on those older ones that do support it..
Tells me it does not have a fully variable Horiz and Vert, which means it could also frame skip at 70Hz and at 72hz or could be wrong but think they would document something about that, at that price 😀

Modern vrr displays can do the 70hz again. I tried out a new cheap dell, it had also smooth vga scroll.

ElectroSoldier wrote on 2023-11-16, 04:13:

I cant say Ive noticed that particular problem as at the resolutions I prefer it runs at 75Hz not 70Hz.

I suppose technically it skips if you apply a certain set of criteria to it to make it happen, but actual real world experience of it throws up none of the problems youre talking about.

I suppose thats the difference between knowing the path and walking the path.

It is likely skipping frames without you noticing that it does, unless you never play games at 320x200@70Hz (standard VGA 256 color mode). The manufacturer likely tried their best to make it as unnnoticeable as possoble.

If you want to be sure there are tests that will highlight the skipping, but if you don't notice it during actual use, there's no reason that you should care.

I personally find it quite obvious when playing Doom, for example. That game maxes out at an actual 35 fps (though screen refresh is actually 70Hz), AFAICR, but frameskip is noticeable to me (I used to be oblivious to it) in most cases when a monitor frameskips 70Hz to 60Hz.

Joseph_Joestar wrote on 2023-11-16, 04:39:

ElectroSoldier wrote on 2023-11-16, 04:13:

I cant say Ive noticed that particular problem as at the resolutions I prefer it runs at 75Hz not 70Hz.

Note that this thread is about DOS games, and most of them run at 70Hz by default.

If a monitor doesn't support 70Hz without frame skipping, those games will not run smoothly.

I wasnt aware of that. I had assumed to stayed with the same refresh rate because when I try and change the resolution without changing the refresh rate then it tells me it doesnt support it... For instance I changed from 1024x768 to 1600x1200 and it can only do that at 60Hz.

darry wrote on 2023-11-16, 07:24:

It is likely skipping frames without you noticing that it does, unless you never play games at 320x200@70Hz (standard VGA 256 co […]
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ElectroSoldier wrote on 2023-11-16, 04:13:

I cant say Ive noticed that particular problem as at the resolutions I prefer it runs at 75Hz not 70Hz.

I suppose technically it skips if you apply a certain set of criteria to it to make it happen, but actual real world experience of it throws up none of the problems youre talking about.

I suppose thats the difference between knowing the path and walking the path.

It is likely skipping frames without you noticing that it does, unless you never play games at 320x200@70Hz (standard VGA 256 color mode). The manufacturer likely tried their best to make it as unnnoticeable as possoble.

If you want to be sure there are tests that will highlight the skipping, but if you don't notice it during actual use, there's no reason that you should care.

I personally find it quite obvious when playing Doom, for example. That game maxes out at an actual 35 fps (though screen refresh is actually 70Hz), AFAICR, but frameskip is noticeable to me (I used to be oblivious to it) in most cases when a monitor frameskips 70Hz to 60Hz.

It is a possibility it does and I dont notice it. Ive only played Cannon Fodder and a try of Space Hulk on it so far. So it could well be skipping frames.

Does it matter what OS you run it on?

It doesn't matter. Frame skipping is inherently tied to a panel native resolution. If monitor skips frames at 70Hz, a scaler don't have enough bandwidth for that.

Yep and panel resolution is tied to the chips/rom that control it. Nearly all LCD/LED panels can run at near any vertical or horizontal (within reason, what LED cannot be flashing at whatever rate you want, within reason) but the electronics that feed those panels are the controllers of what signals are allowed/processed and what is pushed to the display. Is why on http://15khz.wikidot.com/ you see monitors that can do 15Khz horiz for Amiga/Atari and are 1080p. Sure you may have some frame skip on some those listed as Full but it gives a good idea that the limitations are based on the included electronics which is what I was taught in college decades ago. just some alter info...

No I meant does it matter what OS you run the game on?
For instance would Windows 98 lock the refresh rate to 75Hz because its a user preference, while DOS will use 70Hz

Windows 98 default refresh is 60Hz. Everything else depends on drivers and monitor EDID.

ElectroSoldier wrote on 2023-11-17, 09:30:

No I meant does it matter what OS you run the game on?
For instance would Windows 98 lock the refresh rate to 75Hz because its a user preference, while DOS will use 70Hz

Dos uses a lot of different resolutions and frequencies, plus it depends on the card too.

Eg
320x200 13h 70hz (640x400)
640x480 60hz
720x400 70hz
800x600 56hz

And there are the not standard hacky modes, fake mods, uncommon vesa resolutons, chipset dependent modes. It is an art to make a good capture if a demoscene demo uses 3-4 modes, and every uses different timings, frequencies.

The Serpent Rider wrote on 2023-11-17, 20:07:

Windows 98 default refresh is 60Hz. Everything else depends on drivers and monitor EDID.

Yes I know which is why I wrote what I did.

If its a user preference. ie if I deliberately change it and force it to use 75Hz refresh rate will it keep it?

Does anyone have experience with the LG DualUp? (https://www.youtube.com/watch?v=a2h1ZAX_2F4) I'm considering getting that along with a scaler (Retrotink?) for DOS and Win9x. In terms of space, you should be able to get quite a bit out of it.

Vagabund2k wrote on 2023-11-25, 21:15:

Does anyone have experience with the LG DualUp? (https://www.youtube.com/watch?v=a2h1ZAX_2F4) I'm considering getting that along with a scaler (Retrotink?) for DOS and Win9x. In terms of space, you should be able to get quite a bit out of it.

Experience, nope very expensive 60hz productivity screen to risk a test

LG DualUp also has weird aspect ratio which is only applicable to some portable console gaming emulation. Everything else works within confines of 4:3 aspect radio. Also monitors without explicit VRR support may have issues with refresh rates below 60Hz too, should you want to emulate PAL Amiga or something.

They have the LG DualUp at PCWorld...
They seem a little pricy to me

I just don't see the point of that thing for gaming, retro or otherwise.

Even for productivity purposes, I prefer a dual screen setup.

If space is a concern/constraint, a dual monitor articulated arm setup makes more sense to me.

But that's just my opinion/preference.

darry wrote on 2023-11-26, 07:41:

I just don't see the point of that thing for gaming, retro or otherwise. […]
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I just don't see the point of that thing for gaming, retro or otherwise.

Even for productivity purposes, I prefer a dual screen setup.

If space is a concern/constraint, a dual monitor articulated arm setup makes more sense to me.

But that's just my opinion/preference.

i just started to use the ossc with alternative 4:3 readout for vga, it is fine on a 34" ultra wide screen w/o 4:3 mode.

the 1:1 output is very similar sized to a 14" vga display, the 4:3 stretched output interpolated of course, but i liked more than to use some old display. i could fit my retro rig to the same desk setup than my macbooks (for sound i use a usb analogue mixer to manage the more sound cards scenarios to the studio monitors).

i tried with more tricky resolutions (demoscene), or 1024x768 for the win98 - i do not think make sense to hunting some very special displays just for retro purposes. i already ordered an oled monitor for testing, but be honest i am worrying more about the mac text clarity, than the retro output.

for longer term... the retrotink4k or similar will be fine, just they should reduce the price, 750$ 1.5x more than a new console just for conversion.

Dell U2410. 1920x1080p max resolution. It's got a respectable variety of inputs , including composite and component video. It will sync to a 15KHz horz. signal on the VGA port. It usually remembers the last screen position when applying a 15KHz video signal.
I'm using one right now to do experiments and exercises with Tandy 1000 video, without having to worry about burning up my CM-5 or CM-11 monitors by feeding them bad sync signals. A CGA2RGBv2 converts the digital to analog.
I can only see in 16-bit color, but I can definitely tell something is "different" about the color this monitor produces. I ain't gonna call it "bad," just "different." Best I can describe it is the colors are very soft. I rather like it.

I also have a Dell 2001FP manufactured in 2003 that syncs to 15KHz, has comparable variety of inputs, but it does not remember the screen position in 15KHz land. Screen position always starts way off and frequently resets itself. Quite irritating to use this monitor, but it will work in a retro computing emergency.

Regarding the LG Dualup monitor, my train of thought was as follows:
My Retro Room doubles as my home office, and currently, I have 2 x Dell 1440p monitors there for the work computer and 1 x Dell 2007FPB for my retro clients. If I replace the Dell 2007FPB with the Dualup + Retrotink 4k, I'll have:

- A larger screen for my vintage computers that maximizes the available screen space (compared to widescreen monitors).
- An additional (large) monitor that I can use productively for work.
- Use CRT Filters via the Retrotink 4k
- A Retrotink 4k that I can also connect to our 4K TV to run my old consoles there.

It's expensive, but it's also my hobby, and if good results are expected, it would be worth it to me.
If I understand correctly, the Retrotink 4k also doesn't solve the frameskip 70Hz / 60Hz problem, right?