VOGONS


First post, by NightShadowPT

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Hi,

I currently have my 486DX2/66 connected to an LCD monitor through a VGA cable.
It works well enough, but all the games look too blocky due to the way the LCD panels work.

I also have a RetroTink5x that I use for older consoles, where I can apply some filters to add scanlines and/or aperture grid filters making them look more realistic in the LCD.

I have tried connecting the 486 to the RetroTink using some converters, but I cannot seem to be able to make it work.

Has anyone know of a solution that I can use to add the scanlines and aperture grid filters to make my experience more realistic on an LCD?

I understand this is a very specific requirement, but if anyone would understand it would be this forum 😀

Thanks in advance

NightShadowPT
----------------
Compaq Deskpro M 486/66 - 64MB Ram - Compaq QVision 1MB - Orpheus II Sound
Card - 4GB SCSI HDD + 4GB CF Card - SCSI CD-ROM Plextor PX-32TSi - Adaptec WideSCSI AHA-2740W - 3COM Etherlink III Card

Reply 1 of 16, by rasz_pl

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NightShadowPT wrote on 2023-03-13, 03:28:

VGA
too blocky due to the way the LCD panels work.
I also have a RetroTink5x that I use for older consoles, where I can apply some filters to add scanlines and/or aperture grid filters making them look more realistic in the LCD.

scanlines was never a thing on VGA

AT&T Globalyst/FIC 486-GAC-2 Cache Module reproduction
Zenith Data Systems (ZDS) ZBIOS 'MFM-300 Monitor' reverse engineering

Reply 2 of 16, by Datadrainer

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rasz_pl wrote on 2023-03-13, 21:23:
NightShadowPT wrote on 2023-03-13, 03:28:

VGA
too blocky due to the way the LCD panels work.
I also have a RetroTink5x that I use for older consoles, where I can apply some filters to add scanlines and/or aperture grid filters making them look more realistic in the LCD.

scanlines was never a thing on VGA

Any VGA (and up) CRT monitor displaying raster uses scan line, it is the principle of it.
What I think you are talking about is the scan line gap, the blank between each scan line.
And depending of the screen and the resolution used it is perceptible despite being less visible than on TV or professional broadcasting monitor. This is because a how a VGA monitor works (greater refresh rate on horizontal, controlled horizontal sync, shadow mask or aperture grille shape, etc)
But with my NEC Diamondtron screen, I assure you MS-DOS games using 320x200 resolution have scan line gap.

Knowing things is great. Understanding things is better. Creating things is even better.

Reply 3 of 16, by Pierre32

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rasz_pl wrote on 2023-03-13, 21:23:
NightShadowPT wrote on 2023-03-13, 03:28:

VGA
too blocky due to the way the LCD panels work.
I also have a RetroTink5x that I use for older consoles, where I can apply some filters to add scanlines and/or aperture grid filters making them look more realistic in the LCD.

scanlines was never a thing on VGA

Personally when I'm using DOSBox on a modern display I will use a scanline filter. I don't consider it a period correct effect or anything, I just find it pleasing when you're running fullscreen on a big bright IPS!

@NightShadowPT Can't help you with the 5x personally, but keen to see if you have luck. Failing that it will need to be an OSSC.

What are the best Vga to hdmi scalers or peripherals for MS-DOS games ?

New(ish) LED monitors for DOS? Any good (criteria for 'good' specified in post)?

Reply 4 of 16, by rasz_pl

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Datadrainer wrote on 2023-03-13, 22:48:
rasz_pl wrote on 2023-03-13, 21:23:
NightShadowPT wrote on 2023-03-13, 03:28:

some filters to add scanlines

scanlines was never a thing on VGA

Any VGA (and up) CRT monitor displaying raster uses scan line, it is the principle of it.
What I think you are talking about

its what OP is talking about

Datadrainer wrote on 2023-03-13, 22:48:

is the scan line gap, the blank between each scan line.
And depending of the screen and the resolution used it is perceptible despite being less visible than on TV

It wasnt visible on CRT TV either while watching TV. It was visible on TV while using consoles/old computers because those generated 200/240p signal https://en.wikipedia.org/wiki/Low-definition_ … ion#Video_games by forcibly skipping switch to second field. CGA/EGA same deal reusing TV tubes.

Datadrainer wrote on 2023-03-13, 22:48:

But with my NEC Diamondtron screen, I assure you MS-DOS games using 320x200 resolution have scan line gap.

320x400 😀 VGA fixed this problem by introducing line doubling. For scanline gaps to be visible you need a big CRT with really small dot pitch. People who remember scanlines and are nostalgic for them grew up on consoles/TV connected computers/CGA.

AT&T Globalyst/FIC 486-GAC-2 Cache Module reproduction
Zenith Data Systems (ZDS) ZBIOS 'MFM-300 Monitor' reverse engineering

Reply 5 of 16, by maxtherabbit

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rasz_pl wrote on 2023-03-14, 00:05:

320x400 😀 VGA fixed this problem by introducing line doubling. For scanline gaps to be visible you need a big CRT with really small dot pitch. People who remember scanlines and are nostalgic for them grew up on consoles/TV connected computers/CGA.

Or had really big, nice, and expensive VGA CRTs 😉

Reply 6 of 16, by tyrells

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rasz_pl wrote on 2023-03-13, 21:23:
NightShadowPT wrote on 2023-03-13, 03:28:

VGA
too blocky due to the way the LCD panels work.
I also have a RetroTink5x that I use for older consoles, where I can apply some filters to add scanlines and/or aperture grid filters making them look more realistic in the LCD.

scanlines was never a thing on VGA

PhilsComputerLab recently had an interesting video where they showed an older EGA monitor with scanlines.

Reply 7 of 16, by Datadrainer

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To answer @NightShadowPT (Sorry didn't had time before). I think your purpose is to play games on a big screen LCD TV, not a LCD computer monitor.
RetroTINK-5X is an up-scaller for what I understand that can manage signal up to 480i. All what it can do is to input analog fixed 15KHz hsync with variable vsync signals and process them into a framebuffer through configurable filters to output a digital 1080p.
It will absolutely not work with VGA where hsync and vsync are both variable.

For me the main problem is to send native (or converted without change) VGA signals to a LCD monitor is more to get a decent picture because most of MS-DOS games use a non 4:3 display resolution to display in a 4:3 format screen. But that's also true for any machines with analog output.
That is not a problem for an analog display device as the electronics will cover things (common resolutions detection for the case of a "modern" VGA monitor / hardware timing control for machine with TV output or "old" VGA monitor) and adapt the picture to the display surface drawing lines for almost the whole screen surface. But it is a problem when such signal is converted to a matrix of "square dots" as LCD monitors are mode of. That combined with a bad up-scaling (some are better than other though) and the fact getting a good picture calibration for old games is a pain in the ass.

On PCs, from Windows XP, it is safe to use LCD monitors because there was mainly 3D games with configurable output graphic resolution and Windows XP manages color correction of LCD very well if it has the appropriate screen color profile installed.

So... A possible solution, I used many years ago, was to use a VGA to RGB framebuffer. It take a compatible VGA signal and convert it to a RGBV TV compatible signal. Then you can use your RetroTINK-5X to up-scale the output with de-interlacing and scan line gaps to 1080p on your LCD TV. Work very well with low-res games.

But if you absolutely do want scan line gap with PC hardware of around 1994 and you do not want to spend hundreds of dollars for an additional adapter you can get a MiSTer FPGA which can simulate accurately the behavior of many machines including a i80486 core named ao486 and its software can add scan-line gap to the output (should work for this core, but need to be checked to be sure). It's hundreds of dollar too, better value for what it can do and it connect natively to the TV.

You can also use a modern PC (or a Raspberry Pi 4 managing to find one...) and use RetroArch cores based on DOSBox. Less expansive and work quite well with pixel-shaders doing a good job to simulate CRT screen including the ratio correction.

Or try to just enjoy your PC on your LCD screen with blocky graphics and when you can if you want, buy a CRT monitor, no need for an expensive one. And play the right way (just my personal opinion here)

Knowing things is great. Understanding things is better. Creating things is even better.

Reply 8 of 16, by Cloudschatze

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I use a "mini-SLG" variant with a couple of my older PC + LCD combinations. I'm surprised that it's not a better-known option.

Here is a (not great) video demonstration. Do note that you'll want to set the video playback quality to 1080p if it's not automatically selected, else you're not likely to even see the scanlines.

https://youtu.be/3i8mX0-R3Qc

Reply 9 of 16, by megatron-uk

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Honestly, the answer is just OSSC.

My collection database and technical wiki:
https://www.target-earth.net

Reply 10 of 16, by Jo22

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https://mmmonkey.co.uk/scanlines-do-it-yourself/

?

Edit: I wouldn't recommend using pin 9 for power, though.
It was meant to power EPROMs in later monitors etc.
Vintage VGA cards may not even support it (hole "plugged" or defined as N/A).
A little 4,5v lantern battery may do as well instead.

Edit: I'm currently working on building the most complicated version on that site, using spare parts,
because I like to have the 800x600 switch for SVGA adventure games..

Here's a picture of it, it's not complete yet, though.
I've also omitted the switches for wide/narrow and odd/even.

Last edited by Jo22 on 2023-03-22, 07:13. Edited 1 time in total.

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In what to one race is no time at all, another race can rise and fall..." - The Minstrel

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Reply 11 of 16, by Datadrainer

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Great link @Jo22. Very interesting.
So all what is requires as ICs is a line driver and a D flip flop. That's good to know, simple and efficient and most important not expensive to DIY. RetroVGA is Open Hardware and can be easily modified to use an USB port power it optionally (external power source required anyway as it is a 486DX2), adding only a few more components.
Because the OP was talking about RetroTINK-X5 and scan line + aperture grille, I oriented myself to HDMI, but it is clearly specified

NightShadowPT wrote on 2023-03-13, 03:28:

I currently have my 486DX2/66 connected to an LCD monitor through a VGA cable.

So that answers the OP question I think, although partly because for other effects, it sure requires more advanced and expensive circuitry were what I said is valid as alternate solutions.

Knowing things is great. Understanding things is better. Creating things is even better.

Reply 12 of 16, by NightShadowPT

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Datadrainer wrote on 2023-03-14, 11:51:

So... A possible solution, I used many years ago, was to use a VGA to RGB framebuffer. It take a compatible VGA signal and convert it to a RGBV TV compatible signal. Then you can use your RetroTINK-5X to up-scale the output with de-interlacing and scan line gaps to 1080p on your LCD TV. Work very well with low-res games.

I will take a look into this solution... may be exactly what I'm looking for.

Datadrainer wrote on 2023-03-14, 11:51:

But if you absolutely do want scan line gap with PC hardware of around 1994 and you do not want to spend hundreds of dollars for an additional adapter you can get a MiSTer FPGA which can simulate accurately the behavior of many machines including a i80486 core named ao486 and its software can add scan-line gap to the output (should work for this core, but need to be checked to be sure). It's hundreds of dollar too, better value for what it can do and it connect natively to the TV.

I already have a MiSTer (amazing piece of kit) and I know it has great scanline and aperture grill simulation, but my specific requirement is to connect old hardware (my Compaq Deskpro/M 486/66) to the LCD.

Datadrainer wrote on 2023-03-14, 11:51:

You can also use a modern PC (or a Raspberry Pi 4 managing to find one...) and use RetroArch cores based on DOSBox. Less expansive and work quite well with
pixel-shaders doing a good job to simulate CRT screen including the ratio correction.

That's what I'm using in my arcade machine, and my first taste of proper CRT simulation 😁

Cloudschatze wrote on 2023-03-14, 18:12:

I use a "mini-SLG" variant with a couple of my older PC + LCD combinations. I'm surprised that it's not a better-known option.

I'll take a look. Thanks for sharing.

NightShadowPT
----------------
Compaq Deskpro M 486/66 - 64MB Ram - Compaq QVision 1MB - Orpheus II Sound
Card - 4GB SCSI HDD + 4GB CF Card - SCSI CD-ROM Plextor PX-32TSi - Adaptec WideSCSI AHA-2740W - 3COM Etherlink III Card

Reply 13 of 16, by Pierre32

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Cloudschatze wrote on 2023-03-14, 18:12:

I use a "mini-SLG" variant with a couple of my older PC + LCD combinations. I'm surprised that it's not a better-known option.

Here is a (not great) video demonstration. Do note that you'll want to set the video playback quality to 1080p if it's not automatically selected, else you're not likely to even see the scanlines.

https://youtu.be/3i8mX0-R3Qc

Jo22 wrote on 2023-03-14, 21:21:
https://mmmonkey.co.uk/scanlines-do-it-yourself/ […]
Show full quote

https://mmmonkey.co.uk/scanlines-do-it-yourself/

?

Edit: I wouldn't recommend using pin 9 for power, though.
It was meant to power EPROMs in later monitors etc.
Vintage VGA cards may not even support it (hole "plugged" or defined as N/A).
A little 4,5v lantern battery may do as well instead.

I've managed to bumble through so far without scanline generators really coming onto my radar. But they've come up in a couple of these threads in the last couple of weeks and they have my attention. I think I'll have to give one a try. It's a cheap experiment!

Reply 14 of 16, by NightShadowPT

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I've just ordered a Mcbazel Portable VGA Scanline Generator... should take a couple of weeks to arrive.

I'll let everyone know the results of my testing here for the community.

NightShadowPT
----------------
Compaq Deskpro M 486/66 - 64MB Ram - Compaq QVision 1MB - Orpheus II Sound
Card - 4GB SCSI HDD + 4GB CF Card - SCSI CD-ROM Plextor PX-32TSi - Adaptec WideSCSI AHA-2740W - 3COM Etherlink III Card

Reply 15 of 16, by NightShadowPT

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As promised, here I am with an update.

The Mcbazel Scanline generator has arrived and it does what says in the tin... it adds scanlines...

Quality is quite good and makes the games look better as expected.

Nonetheless, I would still like to try and find a solution to connect it to the RetroTink5x because it has really good shadow mask emulation, making it the ultimate retro experience.

One step closer, but not there yet...

NightShadowPT
----------------
Compaq Deskpro M 486/66 - 64MB Ram - Compaq QVision 1MB - Orpheus II Sound
Card - 4GB SCSI HDD + 4GB CF Card - SCSI CD-ROM Plextor PX-32TSi - Adaptec WideSCSI AHA-2740W - 3COM Etherlink III Card

Reply 16 of 16, by MrVernall

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NightShadowPT wrote on 2023-03-24, 16:26:

Nonetheless, I would still like to try and find a solution to connect it to the RetroTink5x because it has really good shadow mask emulation, making it the ultimate retro experience.

I'm currently thinking about getting a RetroTink5x to connect my retro PCs to my 1440p monitor. Did you ever find a solution? I see StarTech make a device (VGA2VID2) that converts and scales a VGA video input signal to a 480i composite (CVBS) or S-Video output signal. Are you aware of this and have you tried it?