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Clean resolution & refresh rate on CRT TV using HDMI out?


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EDIT: I have more options; My video card has HDMI or DVI out, and the TV has Component, or S-Video in. Whatever best converter goes between any one of these, let me know.

 

My custom cabinet is going well so far - I have really good CRT TV, and an older video card with an S-Video out on it that I've kept around through the years - this card has always worked well with CRT TVs using S-Video, and in my custom arcade cabinet I got everything perfect so that the emulation and the video card are set at the proper refresh rate for perfectly smooth scrolling, at what appears to be the native resolutions of the games!

 

My problem is - I want it to do a little more - my cabinet has 4 player controls on it (for TMNT etc.), and I'm wiring them up to disassembled Xbox 360 pads, so that it can also play the plethora of great 4 player games being released on steam. However, at least one of them wants DirectX 11, so I got a new card (cheaply) that supports that - trouble is, it doesn't have S-Video out of course, only HDMI.

 

I'm looking at these "active" HDMI converters, either HDMI -> Component, or HDMI -> S-Video.

 

My concern is, before I shell out for one of these, are they going to do something to the signal that will mess it up in the conversion? They all claim to support 480p (60Hz) and 576p (50Hz) outputs (as well as higher), but can I trust this?

 

Does anyone have any experience with trying to get a clean authentic picture on a CRT TV when your only option is a HDMI out?

Edited by Domarius
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Just to confirm: what resolutions can the CRT TV handle? As in, is it a widescreen HDTV (720p/1080i) or a later model 4:3 SDTV (480i?) that happens to have component inputs? Any marking on the case about 100Hz or Progressive, EDTV, HDTV? Which model video card are you using, and does it have a DVI-I port, or only a DVI-D? What's your setup? PC in a cab, only used for gaming?

 

I'm also curious about how you managed to manipulate the S-video port of the old GPU. Normally those are hardwired to 480i - so no matter what resolutions you set elsewhere, there'd be no way to get a 1:1 rendition of a 15kHz arcade game that used progressive video.

Edited by buttersoft
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Thanks for the enthusiastic response guys :) I can tell you anything you need to know...

 

@buttersoft yeah I need to explain myself a bit better - OK so I managed to fudge something up that to my eye looks 100% perfect, at least for the 8 bit and 16 bit consoles. There are two main problems - swimming pixels when scrolling due to scaling issues, and juddery frame rate when scrolling, due to refresh rates not matching. I set the emulator to 1024x768, disable any filtering options, and this 100% hides any "swimming" pixels when scrolling. To me it looks just as if each scan line is a row of pixels on the CRT. Then I set the Nvidia driver TV output to "NTSC", this also sets the 480i, 720x576 and the refresh rate is locked at 29hz. In the emulator, I enable "Vsync" - et voila - the scrolling (to my eye) looks absolutely smooth and perfect. I'm not sure why it works, since NTSC is supposed to be 60hz, all I know is setting it to PAL causes juddering in the scrolling.

 

The one and only drawback I can see is everything is interlaced - this is especially noticible when sprite flickering effects are used (eg. killing an enemy in Shinobi on the Sega Master System). This is ugly and not authentic. But all the TV out options are interlaced options (eg. 480i, 576i) there are no progressive options (480p, 576p)...

 

I would consider the Soft15kHz route, but I'm really really confused, and would like any advice you have. Info on how to use Soft15kHz effectively seems thin on the ground, it doesn't even have a home page. It might be compatible with the cards I have. But I read an article (here) that said he couldn't get the refresh rates to sync up so everything was choppy. I'd prefer to suffer with the interlacing than go back to choppy scrolling.

 

 

 

Here are the hardware details.

 

Yes, it's a Windows 7 PC in a home made cabinet. I'm rather proud of it, this only being my 2nd woodworking project (after my smaller benchtop arcade). Have had to disassemble for painting and have not put buttons back in yet, also doing away with the iPAC4 and going with hacked apart (chinese knock off) XBox 360 USB controllers, so it can play the newer games, wiring up the d-pad terminals to the joystick inputs and ignoring the analogue sticks, since all the "retro" style games use the d-pad anyway. And the emulators don't mind having their controls mapped to XBox 360 controller inputs.

 

IMG_20161102_204648.thumb.jpg.b7798c4b20d0de0f9cd9579bec362269.jpgIMG_-972550817.thumb.jpg.968c4c4cfee368908a8f4101b277253f.jpg

 

The TV is an "LG" TX-68PS12A, you can google for its manual easily, I think I used this link https://www.manualslib.com/manual/117991/Panasonic-Tx-68ps12a.html It's not a widescreen, it's just a (very good) 4:3 TV with Composite, Component, and S-Video inputs.

 

The OLD video card is an "Albatron" Nvidia 7300 GT, it's the one with the S-Video out - I've used this setup with all kinds of resolutions, I know I used the really low res ones that the 8 bit and 16 bit consoles put out, and in addition to that, I can recall using 640x480, that SD TV resolution 768×576, 800x600, and 1024x768. My good old Albatron video card always sent a signal that the TV understood, given the wide variety of resolutions I tried.

 

The NEW video card that only has HDMI, DVI-I, and DisplayPort out, is an ATi Radeon HD 5670, rather spiffy given I only paid $20 for it second hand (the guy handed it over in a small soup box, haha). Works great though, almost no dust in it. Just a reminder, the only reason I'm trying to get this newer card working with the CRT is it runs a few more of the newer 4 player games on Steam, and they are done in a retro style, eg. "TowerFall" so they look great on the CRT. And also Demul (the Dreamcast emulator) won't work on the other card but works on this one.

Edited by Domarius
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Clean resolution & refresh rate on CRT TV using HDMI out?

 

https://en.m.wikipedia.org/wiki/Refresh_rate

 

These rates formed the basis for the sets used today: 60 Hz System M (almost always used with NTSC color coding) and 50 Hz System B/G (almost always used with PAL or SECAM color coding). This accident of chance gave European sets higher resolution, in exchange for lower frame-rates. Compare System M (704 × 480 at 30i) and System B/G (704 × 576 at 25i). However, the lower refresh rate of 50 Hz introduces more flicker, so sets that use digital technology to double the refresh rate to 100 Hz are now very popular. (see Broadcast television systems)

 

 

Sent from my iPhone using Aussie Arcade

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@Domarius, this is a slightly tricky question due to the resolutions you may wish to use and the nature of transcoding vs scaling vs lag. For older games/emulators/MAME, using a 15Khz mode with a 1:1 vertical ratio is amazing, and can't be beaten. For newer games, if you can't use a 640x480 mode, then you have to downscale the image to get it onto your CRT.

 

The S-video port on your older GPU is only capable of 640x480i, and in every case I’ve seen Windows is happy to slot a 640x480p standard mode into that no trouble. It might flicker a little, but hey, it works. But that port is also capable of taking your desktop at 1080p and shoehorning it into the 480i output, at an obvious drop in quality. So you could run any game at any resolution, if I have this right, and it would come out the S-video port at 480i and display on your 15kHz-only SD CRT TV.

 

The new card won’t do this. So the next question is, can you run everything you want to at 640x480p or lower?

 

If the answer is no, and you need higher resolutions to do everything you want to do, then you want to get yourself an HDMI to Component converter that can output 480i. I have no idea about these, and thus cannot recommend anything , so if someone else would like to contribute that'd be great.. After that, you can ask on the Hardware subforum of the Shmups site, probably in the Questions That Do Not Deserve A Thread thread. If you search that Hardware forum I’m sure someone else has asked.

 

This method is simple, all you do is plug the relevant bits together. The digital processing require to downscale the video signal, and convert it to analog format, does introduce lag. You’ll notice if you’re playing fighting games, shmups and maybe brawlers. It may be that the more you spend on the converter, the better you’ll do all round, but I really couldn’t say.

 

However if the answer is yes, and you only need 640x480 or lower, then, if you want to, you can get significantly better picture quality for these lower resolutions. Doing this will probably be a bit cheaper, and this way also means less lag, but it’s an amount more work and fiddling around.

 

The first things you need are a DVI-to-VGA adapter and a VGA cable, and then a VGA-to-Component transcoder. These units are meant to work well and produce virtually zero lag as there's no scaling going on. I don't know which transcoder to get either, so ask as above. This time you want an VGA-to-Component(YPbPr) transcoder capable of handling 240p & 480i natively, and ideally one that can handle “super” resolutions.

 

Once you have the hardware above, you install crt_emudriver 2.0, using the guide for the 5000 series and above cards. The guide is step-by-step and easy to follow. Make sure to turn on EDID emulation for the DVI-I port only. The 16.2.1 crimson-based driver is brand spanking new, and *might* have issues. But if it works it'll be your best bet for newer stuff, so I'd try it first. This will allow you to get 15kHz modes out of your system - 240p & 480i being the best-known examples. You may also want to look into Atom15, so that the boot screens from your PC are in 15kHz too.

 

You then make sure you have the video modes you want in your system using VMM (in the guide, above, but you may need to add more modes) for the different emulators you use. 640x480i will already be there, as will 320x240.

 

I’m writing up a guide to getting 15kHz modes out of a Windows PC, and why you want to use GroovyMAME and super resolutions, and below is a chunk of it (apologies for the essay). A lot of what is said regarding resolutions applies to other emulators.

 

What is GroovyMAME?

GroovyMAME, by Calamity with input from Intealls, Bytebit and others, is a parallel build of MAME. GM, to save typing it out every time. There’s a lot to know about GroovyMAME, but it’s no harder to actually use than MAME. Connecting your PC to an old CRT is the problem.

 

Why is GM better for CRT?

GM has a built-in function called switchres, which, when left on default settings, selects a video mode with a 1:1 vertical ratio, ideally from a list of "super" resolutions, and adjusts the modeline so the refresh matches the original hardware. The ability to push video which is unstretched and unscaled in the vertical produces an image which is all-but-impossible to distinguish from the original system. This is about the most important feature of GroovyMAME, if one of many.

 

What are Super Resolutions? (What about Horizontal stretching?)

Super just means horizontally larger, here. This allows the image to stretch more evenly in that direction. 2560 pixels wide is the default super resolution trigger GM uses, but you could almost double that without a problem. Some analogue circuitry might hit a dot-clock limit, I’m not sure. Be careful. Any functioning analogue TV can do 2560 though. CRT's are limited by their horizontal scan rate (number of vertical lines they can draw) they are not limited by horizontal pixels (number of dots within each line). They aren’t fixed-pixel like an LCD or OLED, of course. Think of two flyscreens with slightly different mesh sizes lain on top of each other - the electron guns fire a grid of pixels at the shadow mask, and the two never line up perfectly - they can't, it's not physically possible. As long as the number of horizontal pixels you're trying to fit your image into is sufficiently large, the effect is seamless. Obviously the computer has to draw the first flyscreen first, the one the guns will fire at the second screen, dot by dot, line by line. Think of the CPS1 arcade system (SF2, final fight + more) at 384x224. Using 320x240 dots would mean that while the vertical will fit at 1:1, you'd be losing pixels horizontally trying to fit 384 into 320, or just enabling some filter or effect that would only warp the original image. The answer is to use a ‘super’ resolution of 2560 pixels, giving a 7/7/6 pixel ratio for each three original pixels of the 384. The horizontal sync rate remains the same, the electron beam sweeps across the face of the tube in the same interval, so the 2560 pixels are drawn into the same physical space over the same length of time as 384 would be, or 320, or whatever.

 

You can do this horizontally because there’s no hard limit to the number of pixels that can be drawn by a CRT. Careful pushing too far with that, I’m not sure where the analog circuitry will hit its limit. The picture would probably blur well before that, and even the best PC monitors could only resolve something under 2500 pixels cleanly. Projectors are a separate subject, and not covered here.

 

The number of Horizontal lines, however, is one of the main limiting factors of a CRT. Not individual pixels, those are covered above. This time we're talking about lines of pixels. A 15Khz standard definition set won’t go beyond about 288 lines at 50Hz (frames per second). This means that you have to scale 1:1 because most old systems output at about 240 lines, and if you stretch that slightly into say 256, or even 300 or so, the distortion is huge. On the other hand, an LCD with 1080 lines would have more room to stretch evenly. You could even use integer (whole number) stretching so the pixels scale perfectly. However 382x224 isn’t 4:3 when displayed on an LCD, integer stretching or no. And you wanted a CRT for visual fidelity, didn’t you? (If you were wondering, the 224 vertical lines fit into 240 with 8 blank lines each side, which seems to be what Calamity recommends.)

 

Trust me, it looks awesome, and just like the real thing. To achieve this you need modelines like 2560x240 and 2560x256 installed on your system. I'm using 2560x262 for WinUAE as it's the only way I seem to be able to get a 1:1 vertical ratio. Not sure why.

 

GM has other advantages too, like frame-delay to combat input lag, V-sync offset and audio latency options, but those are not addressed here.

 

I want to use GM! How do I connect my Windows PC to my old CRT? (And what are these 15kHz modes people keep talking about?)

Assuming you have an old standard definition TV, PVM or arcade monitor, the first step is to get the right video mode out of your PC. Modes like 240p and 480i. These modes have a horizontal scan rate of 15Khz or thereabouts – the limit to how many horizontal lines of pixels can be drawn on the screen each second.

 

15kHz H-Scan = (Horizontal lines each frame) x (Frames per second)

Roughly

15,750 = 262 x 60

 

That’s for a 240p mode. The number 262 represents the total number of lines in the video frame, 240 visible and a blanking interval of 22 lines, the latter containing information which sizes/positions/centers the line, then tells the beam to return to the beginning position one line lower, to start the next line. 15,750 is the nominal scan rate of an NTSC SD TV.

 

For 480i, we see:

 

15,750 = 525 x 30

 

In each case, the number listed is the number of horizontal lines in the frame (visible lines + blanking interval lines). 240p, 480i have that many visible horizontal lines in each frame, though 240p has twice the framerate of 480i. Interlaced modes, like 480i, typically run at 60 fields per second. The first field draws odd lines – 1,3,5,7 etc. The second draws even lines - 2,4,6,8 and on. The two fields interlace to make one frame, so that’s 30 frames per second.

 

These numbers are not fixed, the product is. You can get a 600i mode into 16.2kHz (where an arcade monitor or PVM will normally cut off) but only at 50i, or 25FPS, which flickers badly. Interlaced modes have a higher res, technically, but if you get seizures I’d be careful sacrificing framerates. In addition, most sets will have cutoff limits. 50Hz-65Hz (Vertical scan, or FPS) and a horizontal scan rate of ~15.6kHz-15.8kHz are about the safe limits for a normal old consumer CRT TV.

 

I read about a method to get 15kHz but I can’t make it work! (Soft15Khz/ArcadeVGA/Powerstrip/Dongles/EDID-overrides/other)

If you use Linux, you don't need to be told what to do next or you shouldn't be using Linux. If you're on Windows, there are a number of ways to install video modelines, but only a few of them work for 15kHz resolutions, and only one is designed to work easily with GroovyMAME.

 

The problem arises because Microsoft, AMD and Nvidia all build scan limits into their video drivers, essentially to protect people from themselves. Sailorsat's Soft15Khz, ToastyX's CRU, or Entech's Powerstrip cannot bypass these limits. They used to work, and still might with cards of the 5000GT vintage, from before 2007 or so. But you need a driver to work on your OS as well. With a bit of fiddling you can still use a modeline tool such as these to install any and all modelines you like, and then set them on your display, but the scanrate-check blocks them and switches to the nearest acceptable mode (often 640x480, but not always, so be careful with a laptop or you'll kill your windows install by setting a mode the built-in screen can't deliver like 800x600i at 50Hz - linedoubling that still gives an LCD-crashing 50Hz rate.)

 

On raw windows video drivers there’s no way out until someone codes one. On a GPU you used to be able to use an EDID dongle to bypass the check, which told the drivers there was a monitor connected with whatever properties the dongle said. Modelines installed by CRU or Soft15Khz would then work. But this method stopped working about 2008/9 for Nvidia cards, and a few years later for AMD. The driver doesn’t care what the ’monitor’ says, the modes won’t work. (All dates are a guesstimate. I'm playing around with this for modern cards as well, beside ToastyX's pixel clock patchers, but no results as yet. And the method I describe below would be better anyway, when doing things from scratch.)

 

The exception is the AMD Firepro and Nvidia Quadro workstation cards, which are more flexible. The dongle will work, but is not needed as those cards have the ability to emulate an EDID, so you can tell the GPU what you want it to do. (CRU and I think powerstrip are capable of overriding EDID, a function built into Windows Vista and up, but not of emulating it, thus they still fail the driver check without further help.)

 

Ultimarc's ArcadeVGA cards are another workable option. Either that or a Firepro/Quadro will let you install a bunch of modelines into windows and use them. The ArcadeVGA comes with its own tools to do so. But you'd need a modeline for each system within MAME, if not each game. The ArcadeVGA does have boot protection, but is more expensive than picking up a second-hand AMD Radeon card locally, which you might do if you wanted to use the method below.

 

The guide goes on to talk about crt_emudriver, but I did that above :)

 

(Note that this is for your 15kHzonly SD CRT TV with YPbPr inputs. An even better picture, if not massively so, comes from using RGB/SCART inputs; you wouldn't need the transcoder, but there may be other concerns like video amplification.)

Edited by buttersoft
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Thanks @MarkOZLAD for the info on refresh rates, it's good to have a clear definitive list finally.

 

@buttersoft Thank you so much. If that is really all the info I need in one place, then this is super helpful, I really appreciate all this, because it seems like info on this 15kHz stuff is all over the place. I have saved your whole post to a document (and MarkOZLAD's links too) in case anything happens to this thread, since this endeavour is going to be a slow burn process. I've decided to stick with the S-Video card and the technique I posted for now, get it all running, have some fun with it & show everyone, get that out of my system, and then if the output quality can be improved, and I know it's possible, it's going to eat away at me till I do something about it.

 

To answer your question - YES, I think everything I want can be done at 640x480 or lower. You see, I only set the emulators to 10248x768 to get rid of the artifacting caused by scaling, so if I instead go a route that doesn't cause artifacting, I don't need 1024x768! The other thing is, even those Steam games I was talking about, I'm pretty damn sure they can all run at low resolutions (I've tried some of them) since they're done in a retro style and are just scaling their already low resolution up to whatever screen resolution you specify. Eg. Towerfall, and Duck Game. In fact even ones that aren't done in a pixelly style still support 640x480 I'm pretty sure, a lot of games seem to support that. Eg. Neon Drive - not authentically retro, but retro in a fantasy kind of way :) This kind of game is cool to have on this cabinet as well.

 

Question: You said 480p coming out the S-Video port will "flicker a little". Will this always be the case? Or is there something about your approach that will improve this?

 

Also what you said about HDMI conversion has put me off it. I don't want to pay for an expensive piece of hardware to find out it introduces lag!

 

I am looking forward to someday seeing the clarity that your method will give. I had a strange experience today, comparing the actual Super Nintendo to the emulated version on my PC, using the same CRT. The SNES is using standard old composite, and the PC is using S-Video. Compared to the PC emulation, the SNES composite image seems very over-bright and the colours more washed out as a result (my non-retro gaming house mate agreed). Also it had some strange speckled artifacting around any high-contrast edges. These things wouldn't have bothered us as kids back in the day. However, I was able to switch on the fly so we could directly compare, and when I switched to the PC emulating the SNES out the S-Video port using the approach I described earlier - the picture was crisper, and the colours were richer! It was a much more pleasing image. This really surprised me, since I assumed the authentic method (the way we ran it back in the day) would have a better picture! I guess what we put up with back in the day was what it was, but nowadays we have tech available to us that can avoid signal degradation, as I recall reading about people making Component out mods for old consoles.

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The S-Video port is not capable of outputting 480p. Only 480i. This is an interlaced mode (vs a progressive one like 240p or 480p) and interlaces two fields, one with odd lines, one with even lines, to make one frame. So instead of the standard 60Hz framerate you can only get 30, and this 30 is drawing lines in different places (odd then even) so it flickers. (There's not much you can do about this over S-Video without spending a lot and learning a lot, I'd guess.) See the section with the couple of equations in my post above. 480p is 31kHz, but an old TV needs 15kHz.

 

Natively, the SNES runs at 256x240, I think it is. Either way, when you disable scaling a 240p mode, possibly a super resolution, will work nicely and look better. Right now you're using 1024x768, so even with integer stretching (scaling at a whole number ratio) the image is blown up, and then shoehorned into the 480i mode from the S-video port. It probably looks ok for the reasons given further above - the higher the number of overall pixels the more evenly whatever you stretch will fit, and thus the more even the image is that you're trying to fit into 480i.

 

HDMI downscaling isn't terrible. But I'm betting you won't be able to get a unit that is all three things: cheap, fast, and high-image-quality. Even then fast is probably a relative term. Upscaling is slightly better, but even then there are issues if you want digital output - which is normally the point.

 

Re: the SNES issues - there are a number of things that could contribute or go wrong :)

 

Is this your original old SNES cable, or one acquired on fleabay? The PAL SNES cable is different to the NTSC one, and expects a 75R resistor between the Video and Ground lines. This could be missing, or possibly broken off. It sounds like this is the case. If this is your original cable, you may be able to, carefully, split the console-end plug and have a look. If it's not that, well, composite is an inferior picture anyway, and the CRT you're running things on isn't new.

 

There are certainly Component mods for the SNES out there, but the SNES can output RGB natively (again, the PAL cable is different) so in theory, if you can get an adapter or make a cable, you could use the transcoder solution. However, if you get into tinkering, an arcade monitor that takes RGB natively might be a better bet, and something like a JPac to connect to it if you don't want to build an amp. That's as good a picture as you can get.

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Okay there we go - thought I had email notifications turned on for this thread, I didn't. Now I do.

 

Ok well I've got some options to consider for the future then, I'm looking forward to tinkering in the long run, after it's set up in it's current state.

 

Well the SNES AV cable is actually a "special" one, refurbished maybe? All I know is the "Computer Traders" store in Chermside was selling new AV cables a few years ago, I vaguely remember they were newly made or something - the bottom line is, they are gold plated, so it should be the best signal quality you could get from composite - it's new, and it's gold plated.

 

Everything about my SNES should be "PAL" as it's the very same SNES me and my brothers grew up with :) The only new thing is the cable.

 

So you're saying the picture quality over composite could be better? I could take a photo of it to see what you think.

Edited by Domarius
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Well the SNES AV cable is actually a "special" one, refurbished maybe? All I know is the "Computer Traders" store in Chermside was selling new AV cables a few years ago, I vaguely remember they were newly made or something - the bottom line is, they are gold plated, so it should be the best signal quality you could get from composite - it's new, and it's gold plated.

 

Got a multimeter? Set it to resistance x1, put one probe on the inside pin of the yellow lead, other probe on the outside ring of the same lead. Disconnect the AV cable entire from both the SNES and the TV. The meter should read 75 ohms.

 

So you're saying the picture quality over composite could be better? I could take a photo of it to see what you think.

 

Errr, yes. RF is worse than composite, but any other signal type is better. The above comments were more based on the fact that you stated the composite picture from an actual SNES was washed out, and that a PC S-Video signal looked notably better. That shouldn't be the case, given the scaling on the S-video signal. At absolute best you'd be getting something about the same quality. So there's probably something wrong with your composite setup - possibly the TV itself, but easier to rectify if the cable is at fault.

 

And passivated zinc is not gold ;)

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  • 1 month later...

Sorry for the late response.

 

Wow ok, I guess it's possible there's something "wrong" with the composite setup. I did as you said with the multimeter, and it stayed at 100% resistance (1). I'm not an expert though, but I'm pretty sure I did it right. I even followed the steps here, https://www.ifixit.com/Guide/How+To+Use+A+Multimeter/25632, My multimeter has a resistance mode testing cd10f22f3fcfacf01ac4ce3d7a21e32f.png.bf900905ad3321bae1599673bc02d29c.png at least, I'm pretty sure what that means. But I even tried skipping to step 6, setting it to 200 ohms (horseshoe symbol), still no dice. The thing always stayed at 1 until I touched the probes together or touched them to the same pin or housing of course.

 

Ok I didn't know it wasn't truly gold, but I guess gold is easier to say than "passivated zinc" and people still know what I'm talking about :)

 

Edit: it's been a week, just tagging @buttersoft

 

Also I have to admit, I can appreciate scanlines now after I got a refurbished Sega Master System and have been comparing the emulation with the real thing. Scanlines hide every 2nd row of pixels and "round things off", especially chequerd patterns. The clouds in Rastan on the original hardware look amazing. But in the emulation you can see the pixelated chequer pattern. The other thing is my refurbished SMS fills the WHOLE SCREEN, while the emulation output wants to have a border of some sorts. But the Windows desktop and the Retroarch interface fills the whole screen, so there must be some emulation settings I can play with...

 

Well, as I said in a previous post, I will be looking into trying your ideas for these 15kHz modes, like I said, it will start to eat away at me, and it is :) I think I would prefer the scanlines in other emulation too, not just SMS, eg. SNES, Amiga, it's just that I never noticed it till now till making comparisons with the direct simplicity of the SMS games.

 

I noticed your 15kHz solution is for Mame (GroovyMame). Do you think it's possible with other systems that Mame doesn't emulate? eg. Sega Master System, Super Nintendo...

Edited by Domarius
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  • 2 weeks later...

Sorry, completely missed the post!

 

YEah it sounds like the SNES cable is causing the image to be washed out. A proper, functioning cable has that resistor.

 

Once you've installed 15kHz modes, any emulator can use them (assuming it's been coded for a 1:1 mode. You'd be either turning off all scaling and stretching (for a 1:1 mode) and going fullscreen, or if using a super resolution, which is handy, making sure you have the right resolution (vertically) for that system. The horizontal just stretches out, but if you re-read my post on page 1...

 

You simply add the modelines you want, to the "user modes + super.ini" or whatever it's called in the same folder as crt_emudriver and VMMaker. Install as per the guides i linked. SNES is 240p, i believe. Which means 240 pixels high.

 

Not sure about most others, but the Amiga can be a pain. Every guide I've seen uses a 288p mode, but that doesn't work for me. I'm using 262p. And 272p for PPSSPP, and 242p for PCFX so i can play with that modes as nothing else really uses it.

Edited by buttersoft
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@buttersoft Thanks man, that's awesome news, I look forward to enabling this for all my emulated games...

 

Ok, regarding the cable, how do I know which one has that resistor? Which one should I buy?

 

I also just did the same test on my N64 cable which is the same, still get 1 for resistance.

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Ok, regarding the cable, how do I know which one has that resistor? Which one should I buy?

 

I also just did the same test on my N64 cable which is the same, still get 1 for resistance.

 

Hmm, it should test the same as the SNES cable, i believe, at 75ohms. Yellow-ended cable plug, one probe on centre-pin, one on outer ring. The meter reads zero when you touch the probes together? And... something, maybe about 10Mohms, just not zero or 1/OL when you touch a probe with each finger?

 

Any PAL N64 cable should do fine. However, if you get on Facebook there are at least 5 or 6 dedicated nintendo retro gaming buy & sell groups. That way you could go for an original Nintendo cable.

 

You should be able to use the N64 cable in the SNES. Does it do anything different on that TV? What about the SNES cable on the N64? If the N64 is the same, and the SNES is the same, it might not be the cables at fault. Then again, the SNES isn't necessarily outputting the same levels as the N64 - they'll be close, but they don't have to be identical.

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  • 4 weeks later...

@buttersoft - I'm back again :) you can expect me to be dipping into this when I have time & when it frustrates me not having it. I have a new reason bearing down on me - the very cool retro 4:3 style games made in modern times on steam (Towerfall Ascension, Shovel Knight, Shantae Risky's Revenge, etc.) run too slow or not at all on my extremely old S-Video card! But I have a ATi Radeon HD 5670 ready to go - it just doesn't output S-Video or Component of course, and so won't work on my CRT TV.

 

So I'm looking into your suggestion for a VGA to Component transcoder (using a DVI to VGA adaptor of course). When I look for this kind of thing on eBay, I get these things, around $30. Is this it, or is this some cheap thing that won't actually convert the signal properly?

http://www.ebay.com/bhp/vga-to-component-converter

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Your link is HDMI-to or HDMI-from converters. You don't want HDMI anything :) You want a VGA-to-YPbPr or VGA-to-Component transcoder. Or a SCART-to-Component/YPbPr one. VGA is probably easier, as the cable is just your run of the mill VGA cable.

 

I've been keeping an eye out and something like this is probably ok - http://www.ebay.ca/itm/VGA-to-Component-Transcoder-Retrotek-VGACTV1-/192116647418

 

Model number is there, so see if you can find it, or something like it, for cheaper mb. Shipping would be a bit of a bitch.

 

Note the important bits of the description:

 

The Retrotek VGACTV1 is a transcoder solution that can completely passively convert any RGBHV or RGBS video into component video with a 100% scalable resolution input/output range from 240p to 1080i. The transcoder does not process any synchronization timing into any discrete steps or apply any or signal processing so ANY resolution will be properly converted to component video output, including all of the non-standard arcade resolutions. This transcoder can handle ANY incoming HV Sync or Composite Sync, both of any polarity or even if the HV sync is of opposite polarities. All incoming sync signals will be properly converted to an accurate negative sync tip for component video with correct timing and voltage. This makes this transcoder virtually guaranteed to work with all types of RGBHV or RGBs inputs you can throw at it! Comes with converter box and accompanying power supply, so everything is ready to go on arrival!

 

VGA is RGBHV (R,G,B, Horizontal Sync and Vertical Sync)

 

This device does not have 15kHz protection though, so the PC has to be outputting 15kHz-only because your monitor is 15kHz. Once crt_emudriver 2.0 is installed, Windows only has access to 15kHz resolutions so you don't have to worry. But the PC will still be using 31kHz or more during boot unless you go the Atom15 route i mentioned on the previous page. Or just wait until you've booted to Windows before turning on the TV.

 

EDIT: actually, there's another thread right now about building your own RGB-to-YPbPr converter, but it's not complete. Not for the faint of heart right now :)

http://www.aussiearcade.com/showthread.php/86709-Silicon-Chip-Subscribers

Edited by buttersoft
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So @buttersoft - would this work with an arcade PCB's RGBs output?

 

 

Sent from my iPhone using Aussie Arcade

 

:p

 

Arcade video input signals need some special care on the RGB lines, while sync can be directly connect (whether its horizontal sync or HV Sync). This transcoder expects an standard RGB input signal of 0.7Vpp, however most arcade boards operate at around 2.4-3V on the RGB lines, so you will need to drop this voltage accordingly with a resistor divider or insert series resistors on the RGB lines (the transcoder terminates the RGB signals at 75 ohms).

 

You could probably just use a resistor and a 1k pot in each line though, but don't quote me on that.

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The levels will be fine from that supergun, and the converter unit takes C-sync happily, but you'd need a way to get the SCART socket to the VGA socket.

 

I believe most passive VGA-to-SCART cables/adapters/gear would wire VGA pin 13 (H- or C-sync) to SCART pin 20 (Video in - the line used for sync) but can't confirm that. The problem might be that SCART uses different pins for Video-in (pin 20) and Video-out (Pin 19), making each male-male SCART cable a crossover cable not a patch cable. So a VGA-to-SCART adapter possibly wouldn't work backward. I don't know enough about the usual practice there.

 

The listing you posted has ended, so I can't see any good pics or specs :/

 

EDIT: sorry, didn't see the BNC bit. A VGA-to-5-BNC cable should work fine if the supergun outputs via BNC connectors. Get a 5-BNC cable rather than a 4-BNC option as it'll be more functional later to connect a PC to an arcade monitor or PVM - http://au.element14.com/pro-signal/psg00843/lead-vga-p-to-5x-bnc/dp/1734850?mckv=s|pcrid|59148083448&gross_price=true&CATCI=aud-112905144048:pla-173777534688&CAAGID=12550800888&CMP=KNC-GOO-SHOPPING-1734850&CAGPSPN=pla&gclid=CN-x-5qy0tMCFZcGKgodhd4J2A&CAWELAID=120185580000103726

Edited by buttersoft
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Scart and BNC PVM RGBs Breakout board

 

for use with Jamma RGBs to Scart or BNC

 

or

 

Breakout of Console RGBs to Scart or BNC

 

Have you ever had the problem of not having the correct type of RGB cable for your console or want to hook up a Jamma arcade PCB to your TV

 

Or even worse still have a nice PVM/BVM monitor and no way to connect to it

 

well with this breakout board you can do exactly that

 

Has a direct connection to RGBs and Audio

 

or you can put the signal trough the attached POT to attenuate the signal

 

with the added addition of a Sync Stripper if needed

 

330 or 390 Ohms for Arcade RGB and 1K Ohm for Sync

 

75 Ohms for conevential Consoles

 

or just have the singal direct if you have internal resistors installed

 

Ideal for Superguns, CMVS, AES, N64, SNES, PC Engine use or testing purposes on your test bench

 

can be used to also strip the sync off PS2, Saturn and many others

 

Youtube video of it in action here

 

 

 

 

Please Note:

 

Jumper and Screw Terminal Colours may vary

 

These will come fully soldered for your convenience, the POTS will be 470 Ohm on the Colour and 2K2 Ohms on the Sync. if you wish for a custom value then please message me at the time of purchase.

 

s-l1600.thumb.jpg.bff8b86688886195ba3cb19a7f3144b8.jpg

 

 

Only has four BNC outputs...

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Only has four BNC outputs...

 

That's fine. The VGA-to-5-BNC cable (in this case running backwards) will work to carry RGBS over 4 lines. And the converter I linked says it takes C-Sync.

 

The recommendation was more about the fact that no modern or semi-modern GPU can output c-sync over VGA, so the 5 cables would be needed to get a complete RGBHV signal out of a PC, if you wanted to do that down the track. You'd need to for a PVM, or to use an Extron or other scaler or sync-combiner.

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