villeneuve wrote on 2021-06-13, 17:51:

Thanks for all the input. So the very cheap/free to get 5:4 displays are not an option for DOS machines if you care about correct aspect ratio etc. which is sad. I do have several CRTs but I wanted to use an LCD for a SVGA & Glide DOS sim/simcade steering wheel racing setup.

Regarding the Dell monitors: The model I have two examples of, the U2311H, does indeed offer 4:3 ratio, but it's always zoomed so that there are only black bars left and right instead of all around AFAIK. I still have to try a DOS PC connected to that display though, but my expectations are pretty low.
Btw I love the look of the bezel of the Dell U2311H and the U2410 has the same style. Just nice plain 90° angles 😀

Yeah, it's difficult to recommend an LCD display for DOS due to the typically lousy scaling and typical issues with non-60Hz refresh rates. I mean, if you're okay with the sacrifices then go right ahead... but finding an LCD that can mitigate those issues can be roughly as difficult as finding an old CRT...

When the resolution is less than 640x480 there's just this distinct CRT look that an LCD can never recreate. At low resolutions you can see the gaps between the scanned rows of a CRT and there's just nothing like it (although the CRT Royale shader in Retroarch is an impressive recreation). Personally I don't find the razor sharp integer scaled 'pixel perfect' look to be more attractive than the boring soft scaled blown up image you'd normally get when scaling 320x200 to say 1280x1024.

villeneuve wrote on 2021-06-13, 17:51:

Thanks for all the input. So the very cheap/free to get 5:4 displays are not an option for DOS machines if you care about correct aspect ratio etc. which is sad. I do have several CRTs but I wanted to use an LCD for a SVGA & Glide DOS sim/simcade steering wheel racing setup.

I agree with bZbZbZ. I use the iiyama 17" LS704UT (Vision Master 1403). It is a 2003 model so it is relatively easy to find, it not as heavy as those 19" models and can go up to 800x600 @ 85 Hz (or 1024x768 @ 75 Hz). It's (imho) a great choice for both later DOS gaming / early Windows in particular FPS games.

The cheapest 1600 x 1200 monitor that I could find anywhere was a Dell 2007FPb, but it's as heavy as a shipment of nuclear fuel rods.

bZbZbZ wrote on 2021-06-13, 20:04:

When the resolution is less than 640x480 there's just this distinct CRT look that an LCD can never recreate. At low resolutions you can see the gaps between the scanned rows of a CRT

I've never seen anything like that except in the mission briefings for, ironically, the Windows 95 port of C&C: Red Alert.

Eh I use a 19" dell lcd and is perfect even for early ega dos games, apart from the barely noticeable vertical scaling.

nd22 wrote on 2020-05-29, 14:14:

Recently I purchased for a very low price an EIZO S2100 with a 21.3 display and 1600*1200 resolution - the colors are amazing and look virtually identical to an CRT. 21.3 is the largest LCD display with and 4:3 aspect ratio.

Nah historically 22 and 23” existed

ViewSonic VP230mb

And apparently 26” but the thing has broken 2003 era display controls (no vertical size controls and terrible color controls, need to use a sync fixer to use the screen)

https://www.unico-usa.com/products/ulm26-unic … nt-lcd-monitors

Good luck finding one! Even 21.3 inches has become expensive and rare today let alone that Viewsonic which must be something of a unicorn!

While additional 1.3 inches are nice, the panel specs are worse than 20 inch.

Eizo flexscan s2133 is the best i found, 21.3 inches, ips led panel , 1600x1200 native, usb, d-sub, dvi, displayport and a great scaler. You can find it used for a decent price. I got mine for 70€.
https://www.eizoglobal.com/products/flexscan/s2133/#tab02

The samsung g8 oled supports 4:3 mode, vrr upto 175hz, no lag, great match with ossc.

I have found other problems with these monitors my Dell 2007FP is starting to squeal, its annoying sound like from graphics card coils.

The samsung g8 oled supports 4:3 mode, vrr upto 175hz, no lag, great match with ossc.

750$, smallest is $32 and how much for OSSC another $200? Its option, but for second room, occasional gaming.

4:3 IPS and VA panels can't do 70Hz - the monitors that contain them will say they do, but they're just dropping frames before sending 60Hz to the panel. The datasheets for the panels show they only accept 58-62Hz or something like that.
Depending what you play you might not notice or care about this. Smooth scrolling with the 70->60Hz conversion will be choppy and irritating. It bugs me in Star Control 2.

So if you want smooth 70Hz DOS on a 4:3 LCD then that leaves TN panels. People don't like them because the image isn't as good, but TN panels can display 70Hz directly without frame drops. That's the compromise.
The only workaround might be a modern-era IPS that can do 70Hz and still has VGA, but I don't know enough to talk about them.

I see 3 commonly available options for TN panels.
1)An old 15-17" 1024x768 15" is much more common. These are among the oldest LCD monitors. 320x200 doesn't scale perfectly.
2)A 19" 1360x768 wide monitor If they have a 4:3 mode, then the resulting size and resolution is the same as a 15" 1024x768. Takes more desk space, but it's a newer display with better image and response time.
3)A 19" 5:4 1280x1024 Much bigger than 15", but image will be stretched vertically to 5:4. 320x200 has integer scaling horizontally but not vertically.
Has anybody ever seen a 1280x1024 LCD that has a "letterbox" 4:3 display mode? It doesn't seem anybody included that option on 5:4 monitors.

For games with constant scrolling I'd rather play on my 19" 5:4 TN panel than my 20" 4:3 IPS monitors. I'm more bothered by stutter than minor stretch.
For games that don't scroll much, I might prefer an IPS for the image quality.
To get it all, you need a CRT.

If scrolling isn't a big concern then the 20" 4:3 1600x1200 IPS/VA monitors like HP LP2065 and Dell Ultrasharps are good, and still show up at thrift stores. Image quality is the same - both brands used the same progression of panels with each generation. Anything 4:3 is considered junk today, but these were the quality monitors of that time.
They have integer scaling from 320x200 and at least some of them have a sharp/softness setting. I have my DOS machine hooked to a Dell 2001fpb right now, and I wish I could set it softer than it allows, but at least it has the option.

Dell has VGA+DVI-D and AV inputs. Most HPs don't have the AV inputs but they have dual DVI-I ports. Each of those supports VGA if you use the correct cable/adapter - so you can use dual VGA with the HPs.
Input differences are the only important reason I know to prefer Dell vs HP, otherwise they're equivalent.
There's a secret code to check the panel part# and display hours on the HPs but I don't remember how. Maybe also on Dell. Dell also has a secret code to test the display (so it doesn't keep going blank for "no signal"). This is useful to check the backlight in-store (a bad backlight will seem to work until it warms up). IIRC it involves holding 2 buttons while you turn it on with no signal attached.
If buying online, a monitor from a private owner is probably less worn. Bulk liquidations from an office probably ran at high brightness and long hours.
I don't know why anybody cares what an LCD monitor weighs. 😀 The 20" IPS monitors are about 15lbs without the stand. An entry-level VESA arm will hold them (I have an LP2065 on one right now).

[edit: Changed "72" to 70Hz. I always get that wrong.]

Fully agree, you hit all the relevant points on observations about refresh rate. Most older LCD displays (that were built in the era when 4:3 LCDs were still a thing) did not actually support 70Hz inputs, but frameskipped such inputs to 60Hz, creating the stutter.

Many modern LCDs do accept up to 75 Hz refresh rate signal to fix up for that fault. But unfortunately by the time modern LCDs ended up doing that "fix", the panels had already moved to 16:9, which is why there are practically no 4:3 era LCD panels around that would also properly support the DOS 70Hz signal.

shamino wrote on 2024-12-02, 03:57:

To get it all, you need a CRT.

There is another way. But to illustrate why/how, let me first highlight one other major challenge that anything based on VGA has, which is not so often brought up.

The major problem with the VGA signal is that it does not provide enough information for the receiving end to automatically reconstruct the input pixels. Mainly, the VGA signal is missing information about two things:
1. the individual pixel clock signal, and
2. the display blanking versus border versus active display area, i.e. the "display blank" and "VGA borders".

The lack of these two things makes it practically impossible for an LCD display/converter/capture device with VGA inputs to automatically get the video right. (here by automatic, I mean "without human calibration/configuration") The first limitation means that there is no direct way for the LCD display to distinguish between 320x200 (which is actually line-doubled to 320x400) and 720x400 video (or simply put, between 80x25 text mode and mode 13h graphics). As a result, for example when I view 320x200 graphics via VGA input on my ASUS ProArt PA248QV, it incorrectly interprets "720x400" for the signal:

Automatically distinguishing from the input VGA signal whether it is 320x400 or 720x400 would require some sophisticated heuristics, measuring either the subtle timing differences in the blanking periods or doing a global picture pixel aware signal analysis, which I haven't seen any LCD display do, probably on the basis of "it's not worth it". They just sample according to the bigger of the two, i.e. 720x400 and call it a day. So like seen in the above screenshot, the displays will then misinterpret the video resolution, resulting in aliasing artifacts.

The second problem, 2. above, is more challenging. Because the VGA signal does not carry information about where a) the active image starts and b) the DOS framebuffer content starts, there are actually several pixels worth of black, followed by a VGA border that frame the image.

For example, if we take that input 320x200 image (digitally captured from the same game):

The VGA signal does not actually "see" 640x400 like above, but it sees an image that has 16 pixels of a border on left and right side, and 7 pixels of a border top and bottom, like this:

So the LCD displays that take in a VGA input, must have subcircuitry that would somehow magically detect the VGA border from the signal, and then crop it away. And they actually do. But here's the problem: this magic detection is actually just a hardcoded assumption that there will always be exactly that number of bordering pixels.

And here lies the disappointment: the above VGA border pixel values were not uniform across video modes or across different clone (S)VGA adapters. (They were actually freely programmable in color and width in all four directions by the graphics programmer!) So if you look up at the very first image in my comment, the analog VGA subsystem on this ASUS PA248QV has got the VGA border cropping wrong (likely because mistaking between 640x400 and 720x400), and hence there is a one pixel seam of cyan "glowing" through at bottom and at right edges of the image. I.e. the hardcoded signal timings values were off there. Poor VGA.

So to summarize the whole thing: even if one had a 1600x1200 display that would technically enable that integer pixel perfect upscaling of 320x200 input DOS content, because of the complexity of reconstructing the correct pixel clock and cropping away the VGA border, I have never seen an LCD display that would have pulled that off (or even cared enough to try), and the resulting image is aliased and often the VGA border "glows" from the edges.

To close off, let me comment on

shamino wrote on 2024-12-02, 03:57:

To get it all, you need a CRT.

and the other way I referred to: here is that same ASUS PA248QV, showing that same Keen image:

This is a pixel perfect integer upscale from 320x200 up to 1600x1200 with the correct VGA border crop, while being framerate-synchronized up to 1/1000th Hz of the input 70.362 Hz. All coming from my 486 Cyrix DOS PC with a VGA card and shown in real-time on that PA248QV. This is the "have-it-all" situation for 320x200 DOS video mode.

The way this is achieved is with CRT Terminator, which sidesteps the analog VGA path and has been carefully implemented to distinguish between several dozens of possible input DOS video modes like 640x400 and 720x400 and their VGA border crops, and has been analyzed on more than a hundred different VGA adapters from different manufacturers. Check out Lossless and pixel perfect video capture of DOS 70 Hz 320x200? for related info and download example video captures.

Note that in particular, CRT Terminator is achieving something that a scanline-based scaler like OSSC v1.8 cannot do. (This is due to a technical problem that scanline-based scaling that OSSC does must also amplify timings in blank, running out of HDMI bandwidth if 1600x1200 upscaling is attempted). OSSC Pro advertises a "full video scaler mode", so they might be able to do the same, but only if one manually programs the needed frame geometry pixel timings into it - CRT Terminator does so automatically. CRT Terminator even works with the custom video modes that games programmers like Pinball Fantasies or Jazz Jackrabbit utilized, and also with Mode-X, which I've seen no LCD display to get right.

There is a very long conversation thread about CRT Terminator at CRT Terminator Digital VGA Feature Card ISA DV1000, maybe by now a bit longer than one may care to read.. 😀

shamino wrote on 2024-12-02, 03:57:

The only workaround might be a modern-era IPS that can do 72Hz and still has VGA, but I don't know enough to talk about them.

The DELL 2209WA is a transitional monitor (from 2009), it is 1680x1050, has a forced 4:3 mode and there are many reports of it doing real 75Hz, though I don't recall if there are any limitations to getting 75Hz over VGA and/or in pure DOS.

Dell 2209WA has 75 Hz without frameskip, but you won't get good scaling from it, because 1050 vertical resolution does not divide nicely with most modes, except EGA 640x350.

shamino wrote on 2024-12-02, 03:57:

The only workaround might be a modern-era IPS that can do 72Hz and still has VGA, but I don't know enough to talk about them.

There are modern IPS monitors that support FreeSync with way higher refresh rates than 72Hz, but of course those don't exist with a 4:3 aspect ratio.

I guess it could still work if you accept the black pillarbox bars to the left and right of the image. On a monitor that is large enough, that might still be acceptable.

As for the lack of VGA, that could be handled with a non-scaling VGA-to-HDMI converter. Those shouldn't add any noticeable lag to the output.

Do you think that even FreeSync monitors down-convert any legacy VGA display modes to 60Hz, even though they could display 72Hz natively? Does anybody here have the equipment on hand to test this?

digger wrote on 2024-12-02, 17:16:

Do you think that even FreeSync monitors down-convert any legacy VGA display modes to 60Hz, even though they could display 72Hz natively? Does anybody here have the equipment on hand to test this?

Maybe if aspect ratio and image quality are not a concern, and the only concern is for refresh rate. I don't have any FreeSync displays, but tested two different ASUS G-Sync displays:

ASUS PG259QN: 360 Hz 1080p IPS. Does not sync to CRT Terminator or OSSC. Does not support 4:3 mode, but supports Aspect and Full.
ASUS PG32UCDP: 240 Hz 4K OLED. Syncs to CRT Terminator (OSSC not tested). Does not support any aspect ratio control, always stretches video to full screen.

With this tiny sample size, my gut instinct would be to skip high refresh rate gaming monitors, whether G-sync or FreeSync.

The best current modern monitors with correct working 75Hz support I know of are ASUS PA248QV and Philips Brilliance 252B9/00. Both are 1920x1200 also. The 4:3 mode in PA248QV is unfortunately this "intelligent" mode that they call it, which is unable to produce 4:3 in DOS 320x200 from VGA input. The Philips Brilliance display did have good "force 4:3" mode iirc, although it is a bit horrible in menus and ergonomy, and built-in speakers are crap.

I use ASUS PA248QV with CRT Terminator as my main retro display. If you have separate speakers so audio quality is not a requirement, then the Philips is also nice (and it was also cheap iirc).

Been running an NEC MultiSync 1760VM on the test bench for a few months...

.... according to the manual, it doesn't support anything below 640x480, however, on all the low res DOS modes I have tried so far, it has not missed a beat, does them all great. However, no SVGA mode from DOS has worked, apart from some 800x600 x16 color modes in a test suite. It's giving no signal/out of range. Maybe the older ISA cards are trying to do 56 or 60 hz or something, I haven't really got into it deep. Possibly I could be running some utilities to specify refresh for modes. But anyway, for the manual suggesting anything in higher res is no problemo, to only seemingly working well at the "minimum" res and below, is kinda weird. Could also be it's not reading the oldschool ID signals, rather than DDC.

BitWrangler wrote on 2024-12-02, 21:15:

.... according to the manual, it doesn't support anything below 640x480

That would be quite ridiculous, given the boot-up mode of most PCs from that time is a 400 line mode (either 640x400 or 720x400 depending on who's describing it). The "low-res" modes are no different since they're output to the monitor using line-doubling.

BitWrangler wrote on 2024-12-02, 21:15:

Been running an NEC MultiSync 1760VM on the test bench for a few months...

.... according to the manual, it doesn't support anything below 640x480, however, on all the low res DOS modes I have tried so far, it has not missed a beat, does them all great. However, no SVGA mode from DOS has worked, apart from some 800x600 x16 color modes in a test suite. It's giving no signal/out of range. Maybe the older ISA cards are trying to do 56 or 60 hz or something, I haven't really got into it deep. Possibly I could be running some utilities to specify refresh for modes. But anyway, for the manual suggesting anything in higher res is no problemo, to only seemingly working well at the "minimum" res and below, is kinda weird. Could also be it's not reading the oldschool ID signals, rather than DDC.

This manual begs to differ.

720x400 is supported. 320x200 is actually line-doubled to 640x400 on the VGA output and all LCD monitors that I know of treat analogue 640x400 as 720x400 because there is no easy way to distinguish them (at least not without complex, probably CPUintensive and not necessarily all that reliable signal processing, AFAIU). This is discussed in several threads here, mostly recently in the CRT Terminator this very thread. Re: Good 4:3 LCD Monitor

Well firstly, I think I must have been looking at a shitty scan that blanked that line, and secondly, I haven't really thought of that as a lower mode before, more like equivalent to 640x480 but a different shape. But thanks for clearing things up re the doubling the scans etc.