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Reply 260 of 278, by Horun

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Thanks ! since I have a gtx960 that is in use regularly is good to see a test with it.

Hate posting a reply and have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. 🤣 Second computer a 286 12Mhz with real IDE drive ! After that came 386, 486, Pentium, P.Pro and everything after....

Reply 261 of 278, by cde

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darry wrote on 2020-09-07, 00:23:

I am pretty certain that you have inverted your 720x400 and 640x400 sampling pictures . 640x400 sampling should be the one that displays correctly (proper letter width in Doom status bar) when VGA card is in 320x200 .

EDIT : I am really not sure with there are no sampling artifacts in your 1:1 VGA screen photo .

Darry, I just rechecked and I confirm the GTX 960 resamples 320 pixels to 720. I believe the pictures below should convince you (I've drawn a checker pattern in Deluxe Paint 2) :

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Reply 262 of 278, by darry

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cde wrote on 2020-09-07, 19:26:
darry wrote on 2020-09-07, 00:23:

I am pretty certain that you have inverted your 720x400 and 640x400 sampling pictures . 640x400 sampling should be the one that displays correctly (proper letter width in Doom status bar) when VGA card is in 320x200 .

EDIT : I am really not sure with there are no sampling artifacts in your 1:1 VGA screen photo .

Darry, I just rechecked and I confirm the GTX 960 resamples 320 pixels to 720. I believe the pictures below should convince you (I've drawn a checker pattern in Deluxe Paint 2) :

Wow, I was not expecting that ! That means that they actually implemented a workaround for LCD monitor that sample at 720x400 . And since CRT monitors don't care, they will display correctly too ( you only lose some sharpness to the video card scaling 320x200 to 720x400 instead of line doubling). In an ideal world, being able to turn off this "workaround" for use with a CRT or external scaler or line-doubler .

EDIT: Not sure of this following part anymore. I will need to (re)-check.
Since my GTX750 Ti does 640x400@70Hz over VGA in mode 13h, Nvidia likely actually implemented this only in the last generation that does VGA . I find that quite ironic .
EDIT2: I was wrong about the GTX750 Ti doing 640x400@70Hz over VGA in mode 13h . It actually outputs 720x400 , if you can convince it not to upscale to monitor native (by depriving it of an EDID) .

Last edited by darry on 2020-09-08, 03:04. Edited 1 time in total.

Reply 263 of 278, by cde

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Indeed 😅 Also the last generation of cards with drivers for Windows XP (that even include OpenCL 1.2 support)! BTW I have tested in the same configuration a card of this era, the AMD R9 380X and without an EDID it will always output the image as 800x600@60 Hz, even over VGA, when in 80x25 or 320x200 mode.

Reply 264 of 278, by darry

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I had an interesting turn of events today . I tried my Zotac GTX750 Ti and my spare Gigabyte GTX750 Ti (that I managed to dig out) and tried both of them connected to my OSSC . The OSSC detects their VGA out as 806p on boot , but I am unable to get a picture through the OSSC's HDMI out on either my Philips 252B9 or my Cam Link 4K capture card . If I connect either GTX750 Ti card to the 252B9's VGA port directly, it works fine .

I tested my OSSC with VGA input up to 1600x1200@60Hz with my Voodoo 3, among other cards, without any issue .

Does anybody have any ideas ?

Reply 265 of 278, by Horun

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darry wrote on 2020-09-08, 02:09:

I had an interesting turn of events today . I tried my Zotac GTX750 Ti and my spare Gigabyte GTX750 Ti (that I managed to dig out) and tried both of them connected to my OSSC . The OSSC detects their VGA out as 806p on boot , but I am unable to get a picture through the OSSC's HDMI out on either my Philips 252B9 or my Cam Link 4K capture card . If I connect either GTX750 Ti card to the 252B9's VGA port directly, it works fine .

I tested my OSSC with VGA input up to 1600x1200@60Hz with my Voodoo 3, among other cards, without any issue .

Does anybody have any ideas ?

I do not have an OSSC yet so do not know what 806p means, but could be HDCP handshaking or something else Video BIOS related. Perhaps the cards are trying to connect first at max res and not getting the proper feedback like you mentioned before. Have you tried the same trick you told me ? Hook it up, boot it up then switch cable. Never mind am sure you already tried that.

Hate posting a reply and have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. 🤣 Second computer a 286 12Mhz with real IDE drive ! After that came 386, 486, Pentium, P.Pro and everything after....

Reply 266 of 278, by darry

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Horun wrote on 2020-09-08, 02:39:
darry wrote on 2020-09-08, 02:09:

I had an interesting turn of events today . I tried my Zotac GTX750 Ti and my spare Gigabyte GTX750 Ti (that I managed to dig out) and tried both of them connected to my OSSC . The OSSC detects their VGA out as 806p on boot , but I am unable to get a picture through the OSSC's HDMI out on either my Philips 252B9 or my Cam Link 4K capture card . If I connect either GTX750 Ti card to the 252B9's VGA port directly, it works fine .

I tested my OSSC with VGA input up to 1600x1200@60Hz with my Voodoo 3, among other cards, without any issue .

Does anybody have any ideas ?

I do not have an OSSC yet so do not know what 806p means, but could be HDCP handshaking or something else Video BIOS related. Perhaps the cards are trying to connect first at max res and not getting the proper feedback like you mentioned before. Have you tried the same trick you told me ? Hook it up, boot it up then switch cable. Never mind am sure you already tried that.

When displaying 806p, the OSSC was receiving 1024x768 because the PC had booted into Windows . When I boot into DOS, I get 449p (probably the total number vertical of lines including active, porches and sync pulse) .

I also found the cause of the issue. It was the HDMI switch that I am using between the OSSc and the monitor ! For some reason, this switch that has no issues with all kinds of oddball resolutions generated by the OSSC from an FX 5900 or a Voodoo 3 somehow barfs when near identical resolutions are sent to it by the OSSC as processed from either of my GTX750 Ti cards .

Anyway, once I eliminated the switch:

a) I can confirm that a GTX750 Ti does not upscale to monitor native resolution over VGA when connected to an OSSC (probably due to lack of EDID), so same behaviour as cde's GTX960
b) I can confirm that a GTX750 Ti upscales (probably line-doubles first) 320x200 to 720x400 when outputting through VGA to the OSSC, so same behaviour as cde's GTX960 .
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I am curious as to the Nvidia generation where the behaviour described in point b began .

EDIT : I am also curious as to whether Nvidia actually ever documented the behaviour in point b . Before cde noticed it, I had never heard about it .

Reply 267 of 278, by bestemor

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So, me just 'researching'...
Anyone of you technically savvy peeps that have any inkling if a scaler/switcher can be used as a signal converter as well ?

- In particular this model : Kramer VP-728
https://k.kramerav.com/downloads/manuals/vp-728.pdf

VGA(in) to HDMI out (monitor) that is....

Reply 269 of 278, by darry

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bestemor wrote on 2020-09-24, 14:36:

And if is possible, exactly 'how' would one set it all up, connection wise etc ? 😊
Kramer728.JPG

Well, if you want suggestions, it would probably be easier knowing what devices you want to connect and to what monitor(s) .

That switcher looks like it supports 70Hz VGA as input, so you should be good for that .

Reply 270 of 278, by bestemor

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Well, I was just wondering if it technically would work at ALL, on a basic level ..
('cross-switching' the signal types, as in analog to digital etc)

I mean, this is apparantly _just_ a scaler and a switcher(?), and not a converter ?

Hence me not sure what would happen if I connected the VGA out from a basic video card of a PC to the VGA-in on the scaler, and then a HDMI cable from the scaler's HDMI-out-connector to a HDMI monitor.... and pressed some buttons...

Would the VGA in-signal magically appear as out on the HDMI line and showing a picture on the monitor, if I pressed the correct button(s) ?
(and not just being limited to going directly to only the VGA out, I mean, because there is no signal type conversion implemented )
VGA in must go as VGA out. And HDMI in only as HDMI/DVI etc out.

...if that made any sense.... ? 🤔

Reply 271 of 278, by imi

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Digitally reprocesses the signal to correct mastering errors and regenerates the video at a higher line and pixel rate format, providing native-resolution video for LCD, DLP and plasma displays

so in short, yes 😀

the two outputs merely give you the option to connect either, or both.

if you're luck you can set the output rate at 70Hz as a custom resolution, I have not yet gotten around to play around with my Kramer scaler if that works.

Reply 272 of 278, by darry

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imi wrote on 2020-09-24, 18:00:
so in short, yes :) […]
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Digitally reprocesses the signal to correct mastering errors and regenerates the video at a higher line and pixel rate format, providing native-resolution video for LCD, DLP and plasma displays

so in short, yes 😀

the two outputs merely give you the option to connect either, or both.

if you're luck you can set the output rate at 70Hz as a custom resolution, I have not yet gotten around to play around with my Kramer scaler if that works.

That is a fine piece of equipment, but depending on your needs, it may be both suboptimal on one front and overkill on another, or it may be perfect for what you want to do . That's why I was asking about what you want to connect to it .

Reply 273 of 278, by bestemor

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....to a HDMI monitor ! 😄
and a VGA card....

(or did you mean exact model names ?)

Basically using it as a scaler/converter etc... like the Extron 300 .
Perhaps slightly overkill (?), but if I can get it cheap enough why not....

Reply 274 of 278, by darry

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bestemor wrote on 2020-09-24, 22:08:
....to a HDMI monitor ! 😄 and a VGA card.... […]
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....to a HDMI monitor ! 😄
and a VGA card....

(or did you mean exact model names ?)

Basically using it as a scaler/converter etc... like the Extron 300 .
Perhaps slightly overkill (?), but if I can get it cheap enough why not....

The monitor brand/model would be nice .

One consideration that comes to mind is latency . The more complex the device, the higher the chance of latency . This type of equipment was not necessarily designed with low latency in mind .
Additionally if you already have the device, selling it for a profit and buying something better for your needs might be an option .

As for considerations about this device's suitability to task, here are some things to consider
a) potential latency (as mentioned before)
b) ability to output 70Hz when 70Hz is input (as mentioned in a previous post, this may be possible by defining a custom output resolution), if this important to you (if it is, your monitor needs to support this too)
c) How sharp do you like your video ? Something like OSSC, which does line doubling, not scaling, will be sharper, but blocky (big pixels), but its suitability depends on your monitor's ability to accept 70Hz, odd resolutions and the presence of a 4:3 mode in the said monitor's settings (unless you like your 4:3 contents horizontally stretched).

Reply 276 of 278, by bestemor

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Ahh, latency...! Definately did not think of that ! 😳

As for monitor, I do not yet know.

This was more in the vein of generic future proofing, when all my VGA monitors had expired from old age or too many hours, and because these scalers will be impossible to find by then...
As in, should I buy this thing now, or not...
At some point in time we would then probably call it lucky if we at all got a signal/picture from a VGA PC to show, soft picture or not... 😮
...unless someone by then had 'invented' a really great scaler converter, of course, heh....

But for arguments sake, let's say we use the EIZO Foris 2333, now via HDMI...
Granted, there is no hard 4:3 setting, but the 'enlarged' option keeps the aspect of the input at least(?), so... better than nothing.
And I don't think it outputs 70hz via HDMI, only via VGA input.

Reply 277 of 278, by cde

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According to https://k.kramerav.com/downloads/manuals/vp-728.pdf the Kramer VP-728 seems much less capable than the OSSC for the purpose of DOS gaming:

- no mention of 640x400, so 320x200 games will probably be sampled at 720x400 leading to artifacts (doubled pixels). OSSC handles that problem by providing a 640x400 sampling option
- no guarantee that you'll get 70 Hz on the HDMI output
- no guarantee about the latency/input lag the Kramer VP-728 adds (the OSSC has no input lag)

The OSSC also provides a line doubling mode which is perfect for 640x480 (you get 1280x960) if your monitor has a 1:1 mode, in this way you have a pixel perfect image.

In short I would recommend getting the OSSC, and a monitor with a 4:3 mode (and optionally 1:1 mode) and can handle 70 Hz with no frame skipping. I use the AOC 2590PX (144 Hz with 17" 4:3 and 1:1 option) and darry uses the Philips 252B9 which provides a pixel perfect upscaling of 320x200 to 1600x1200, see I tested several pci video cards for picture quality in dos games.

Reply 278 of 278, by darry

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cde wrote on 2020-09-25, 19:09:
According to https://k.kramerav.com/downloads/manuals/vp-728.pdf the Kramer VP-728 seems much less capable than the OSSC for the […]
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According to https://k.kramerav.com/downloads/manuals/vp-728.pdf the Kramer VP-728 seems much less capable than the OSSC for the purpose of DOS gaming:

- no mention of 640x400, so 320x200 games will probably be sampled at 720x400 leading to artifacts (doubled pixels). OSSC handles that problem by providing a 640x400 sampling option
- no guarantee that you'll get 70 Hz on the HDMI output
- no guarantee about the latency/input lag the Kramer VP-728 adds (the OSSC has no input lag)

The OSSC also provides a line doubling mode which is perfect for 640x480 (you get 1280x960) if your monitor has a 1:1 mode, in this way you have a pixel perfect image.

In short I would recommend getting the OSSC, and a monitor with a 4:3 mode (and optionally 1:1 mode) and can handle 70 Hz with no frame skipping. I use the AOC 2590PX (144 Hz with 17" 4:3 and 1:1 option) and darry uses the Philips 252B9 which provides a pixel perfect upscaling of 320x200 to 1600x1200, see I tested several pci video cards for picture quality in dos games.

I agree .

OSSC is the likely best solution if your monitor is 4:3 capable (or has an equivalent mode) and can handle 70Hz input, but OSSC and a new monitor may be more than you are willing to spend .

The Extron RGB DVI/HDMI 300 is likely the best and cheapest solution for a 60Hz monitor and/or one that can't force 4:3 .

EDIT : The EIZO Foris 2333 monitor may be great for modern applications, but unless it has an explicit 4:3 mode, it will likely stretch non square pixel resolutions like 640x400, that are supposed to be 4:3 , because from the monitor's perspective, 640x400 is 16:10 if the monitor assumes square pixels (which it likely does). This will not be an issue with a digitizer scaler like the Extron RGB DVI/HDMI 300 or even that Kramer unit because you can choose to scale to a 4:3 square pixel resolution, which almost monitors will be able to display as 4:3 . Additionally, I am pretty sure at least the Extron unit supports letterboxing 4:3 content when upscaling to a 16:9 resolution .