15KHZ on a 31KHZ Monitor

[slapaham]

Just wondering what would happen if you were to do this...

[Jack Burton]

At best you will get an "Out of sync range" message.

At worst you will damage your monitor. 

Don't do it.  It won't work. 

If you need to display a 15khz image on a 31khz monitor there are ways to convert the signal.

[genesim]

Yes, like the Ultimarc Arcade VGA.   Version 2 has LCD support.

[RandyT]

To use as 15khz (CGA)  signal on a 31khz (VGA) monitor, you need an "upscaler".  They can be a bit tricky to find, especially with RGB inputs (usually SCART RGB compatible models have this) and even when you do find one, it's hard to know if it's suitable for gaming.  Most will have some sort of motion artifacting, usually visible on games which scroll vertically.

RandyT

[slapaham]

 :cheers:Cheers guys! Yes, I had no intention in trying it out, so no need to worry there, hence, the question!

I think this is a great suggestion...

Yes, like the Ultimarc Arcade VGA.   Version 2 has LCD support.

I haven't got an expert knowledge of the ArcadeVGA but I can remember reading about this feature. Look like I will need to look into this a bit more

Thanks again!

[Jack Burton]

:cheers:Cheers guys! Yes, I had no intention in trying it out, so no need to worry there, hence, the question!

I think this is a great suggestion...

Yes, like the Ultimarc Arcade VGA.   Version 2 has LCD support.

I haven't got an expert knowledge of the ArcadeVGA but I can remember reading about this feature. Look like I will need to look into this a bit more

Thanks again!

I don't get what use an ArcadeVGA has here.  It is a graphics card that is capable of outputting a 15khz signal from a computer to a 15khz arcade monitor or equivalent.  I have heard that it has some nice built in scaling though.  But for a pcb it's useless.

For 31khz signals from a computer any old on-board graphics or graphics card should do.

If you want to send the signal from a 15khz arcade game pcb to a 31khz monitor you will need an Upscaler just like Randy suggested. 

If you are going to go ahead and buy a converter I would instead recommend a converter like the J-ROK RGB to TV converter and use a televison for display instead of a 31khz monitor. 

[genesim]

If he is talking about a PCB then getting it to a computer then pushing it back out could work no?

Is this impossible?

But as far as modulated the 15khz signal, I thought it was quite capable of doing this through MAME.

Just asking though.

Judgeing from the website I thought the Ultimarc card was essential in this capacity of having all the options.


The title of the thread was a little vague...15khz on a 31khz.  That doesn't always equate to PCB, but even if it is can the signal be processed through a card?  In to out?

[genesim]

In looking at Ultimarcs website for the ArcadVGA version 2, there seems to be some kind of scaling of a 15khz signal to PC monitor standars which I assume are much higher.

So barring a arcade PCB source...which hasn't been specified by the poster was out of line for suggesting the Ultimarc card?

[DJ_Izumi]

There's no means to run a 15khz signal on a 31khz monitor.  It's gonna be out of range.  There's  no 'special output' that will make it work unless you scale the signal up to something 31khz which is what he'll probably have to do.  He'll just have to increase his output resolution to something that falls within range of the monitor.

[CheffoJeffo]

About the only things that I have seen put out 15KHz are arcade PCBs and CGA video cards, but since I believe the question is in reference to this setup, I'll assume that he wants to play standard res arcade PCBs in a VGA cab.

slapaham -- you may want to check this guy's project out, if I am correct in my assumption:

http://www.russprince.com/cabinet/

All of the caveats that RandyT put forth apply -- it seems to be hit and miss for converters and upscalers and applicability to gaming.

[genesim]

Can someone please explain to me what Andy is talking about when he is puting a 15khz signal to a PC monitor of today?   Or is this just an emulation of it and not truly 15khz?

Is MAME not capable of putting out a 15khz signal?

[CheffoJeffo]

Please provide a reference so that we know what you are referring to.

[genesim]

http://www.ultimarc.com/avgainf.html

Now you can also connect an ordinary PC monitor and get all the resolutions of the 15Khz monitor plus conventional higher Windows resolutions.

All the native game resolutions are available on bith the arcade and the PC monitor.

[genesim]

About the only things that I have seen put out 15KHz are arcade PCBs and CGA video cards

If this is true, then what is the purpose of Advance MAME?

[CheffoJeffo]

About the only things that I have seen put out 15KHz are arcade PCBs and CGA video cards

If this is true, then what is the purpose of Advance MAME?

Making a VGA video card act like CGA video card ?

I guess I should add ArcadeVGA cards and cards running under Soft15KHz as well, but if they are putting out a 15KHz signal, to my mind the cards are behaving as CGA.

[genesim]

Thats not the way I read it at all.   They are taking 15khz signal and converting it to a way that a modern day PC can express it while still maintaining the inegrity of the original signal.

I mailed Andy how he did this, but I guess this is patent.

But as it stands when you look at the MAME output I remember it showing this...somehow it was proven, but that was a year ago.

Still I am curious how you arrive at the fact that CGA Cards or PCB's are the only thing that put 15khz signal.   Is this how the program works?  Thus Advance MAME?

[CheffoJeffo]

 

[genesim]

Fine its only what you said.   Sorry for ever asking anything different and trying to understand.   You have spoken.

[ahofle]

He's doing line doubling I believe.  Basically running the same resolution, but at a much higher refresh rate (actually running at 31khz).

[genesim]

Hence a conversion is taking place because it starts with the 15khz signal from MAME?

Isn't this actually the exact opposite of a CGA card that output 15khz signal?

[CheffoJeffo]

When I referred to the ArcadeVGA as a CGA card I was talking about its capability to output a 15KHz signal to drive a CGA monitor, as opposed to using it to generate lower resolutions (e.g. those used by CGA monitors) with a 31KHz signal on a VGA monitor.

[ahofle]

Hence a conversion is taking place because it starts with the 15khz signal from MAME?

Isn't this actually the exact opposite of a CGA card that output 15khz signal?

MAME doesn't produce any video signals.  It 'draws' the screen buffer in memory similar to how the original game would have.  This buffer is then 'applied' or copied to the selected resolution.  If you are using Direct3D or DirectDraw with hardware stretch, the screen is scaled to the selected resolution.  If DirectDraw and no hardware stretch, it is copied directly (plus any necessary borders to fit into the selected resolution are added).  That's my understanding anyway.

[genesim]

Cheffo,

I am not talking about that function of the ArcadeVGA.   I am talking about the scaling function as Ahofle has said.

Ahofle,

Yes I guess my confusion is emulated signal vs hardware induced signal.

All that matters to me is a proper emulation of the chipset.    That is what the ArcadeVGA is doing and I guess that is where we separate.   I understand your point.

[CheffoJeffo]

I am not talking about that function of the ArcadeVGA.   I am talking about the scaling function as Ahofle has said.

I know, but *I* was when I was talking about the only think that I can think of that put out a 15KHz signal are CGA cards (or cards acting as CGA cards) and std res arcade PCBs, which you questioned.

[genesim]

My mistake.   I didn't understand the hardware.   If you anyone knows differently please post.

So in closing the 15khz that Andy is quoting being scaled from MAME is like an emulated 15khz signal and not a true one?

[slapaham]

Christ! Last time I looked this morning there were only a few replies... I haven't read all the posts so far but I'll explain why I asked such a (seemingly) daft question!

A couple of days ago I suggested splitting the video signal from a PC to 2 cabinets - so I could either have player 1 on cab1 and player 2 on cab2 or even a 4 player set up. The 2 cabs in question are a Sega Naomi Uni (31Khz monitor) and a Taito Egret 2 (15Khz/25Khz, I believe). Now having purchased a JVS-Pac and a J-Pac I wanted to have both cabs linked up to the same PC at the same time. However, using Soft15Khz wouldn't be a suitable option from what people have said, as it would only work on the Egret and not on the Naomi. Therefore, I need an option which can output at 31KHz and at the same time output at 15KHz or 25Khz... having looked at the Ultimarc website the new ArcadeVGA seems to allow for this, saying that it can do both at once...

If I'm not mistaken, I think I have concluded this one...

No issues with Jamma PCBs, if I can't get them up and running by now I don't deserve to own a cab!

[RandyT]

Be sure to report back if you go this route.  I'm curious as to whether you can get both to fill the screen the way you are hoping it will.

Also, remember to add some context next time

RandyT

[slapaham]

Randy, I was half asleep when I wrote it!

Well, this looks like the only route so when I eventually take it, I will let you know but don't expect it to be too soon!

[RandyT]

Well, this looks like the only route so when I eventually take it, I will let you know but don't expect it to be too soon!

Seeing that you are in the UK, any "upscaler / line doubler" products available to your locale will have a higher probability of RGB input compatibility than what is usually offered in the US by virtue of the SCART interface.  So if your first approach doesn't get you where you want to be, you can still explore that possibility.  Some of the converters do ok, but finding out which ones will likely take some effort.

On the same note, you can go the other direction as well (if you really end up needing to).  You could use a standard, dual-out VGA card to drive the 31khz monitor directly from one output, and use a SCART/RGB compatible "downscaler" (AKA: PC to TV converter) to drive the 15khz monitor from the second output.  Again, there would likely be a quality tradeoff that would need to be considered, but this approach will likely provide more options in the way of more common hardware.

RandyT

[slapaham]

Cheers Randy, good information! I'll consider it but I guess what might be a good idea is to get in contact with Andy from Ultimarc first and ask him a few questions - it just seems like a simpler, more dedicated option (if it works! ) but it doesn't do what I hope then I can always pursue what you've suggested as an alternative.
 

[Ummon]

Gene, read the monitor wiki. Pretty straight-forward.

[Jack Burton]

Tell me if this is crazy, but can he program soft 15khz to let him have some resolutions in 15khz and some outside of it?

This way he can send native resolutions to one monitor and scale to the other as long as his graphics card allows him to clone a display at different resolutions across two monitors. 

Isn't it pretty similar to cloning a pc display to a TV while running your desktop on a pc monitor at whatever res you want and letting the card scale down the cloned image for the tv?

Also, is it possible to use two video cards to send two different resolutions from MAME to two different displays?   

[genesim]

Ummon nice advice, but my response was about software with the ArcadeVGA interface, not the monitor.   

The ability of the output of the card itself was never in question from my end.   

[genesim]

My line of thinking is this, if you can get the 15khz signal to the ArcadeVGA then the card can scale the resolution.   Unless it doesn't work that way and uses MAME code only, which is most likely the case.

So in effect it is a little decieving because it isn't real 15khz signal but "soft" signal like everyone else is saying.

Then of course you have to go with a box like I used to get a Playstation to a PC monitor.   I myself had ok results but it was a pain in the ass with varied results.

I know that scalling occurs with a progressive signal pretty good, but there you are dealing with alot better signal and alot more pixels.

[1UP]

Now you can also connect an ordinary PC monitor and get all the resolutions of the 15Khz monitor plus conventional higher Windows resolutions.

Genesim, you have to understand that the ArcadeVGA was originally made to output from a PC to an ARCADE monitor.  What Andy is saying is that, now you can use it with a PC monitor instead of and arcade monitor.  The arcade monitor would be what is using the 15khz, not the PC monitor.  Unless I'm mistaken.

[genesim]

I got that, I really do.

But my point is that a scaling is occuring and perhaps this technology can be of use here.   It is what I have been saying all along.

But of course I have to completely understand how this was achieved.    And of course how something like Advance MAME outputs the 15khz signal to a arcade monitor if it is like what ahofle said where it is just drawing and not really 15khz.

[Jack Burton]

Genesim, all models of the arcadeVGA and advancemame are capable of sending "true" 15khz signals to an arcade monitor. 

15khz only arcade monitors won't accept any signal other than a 15khz one (or in a few cases 16khz).

The arcadeVGA is completely independent of MAME when it comes to producing a 15khz image.  People display all manner of emulators and applications in 15khz through it, and you can even view windows in 640x480i. 

[genesim]

I am getting frustrated.   I am talking about emulator to grapics card and everyone keeps telling me graphics card to monitor.

I guess I just don't understand at all.

From my understanding the Ultimarc Arcade VGA is taking a 15khz signal of some kind and scaling it to PC resolution.   

I would really like to understand this part.   

What comes out, is immaterial to me.  It is what is coming into to be processed by the card that is supposedly different from a PCB. 

[Bluedeath]

i suggest you to start reading the WIKI it will help you a lot.

[genesim]

Or how about answering the direct question?   

Even on here there is conflicting information.

MAME doesn't produce any video signals. 

all models of the arcadeVGA and advancemame are capable of sending "true" 15khz signals to an arcade monitor.

xxxxxxxxxxx

The arcade monitor would be what is using the 15khz, not the PC monitor.

(referring to Arcade VGA on Ultimarc's site)All the native game resolutions are available on both the arcade and the PC monitor.

xxxxxxx

Then of course this is this.

About the only things that I have seen put out 15KHz are arcade PCBs and CGA video cards

Then I say:

If this is true, then what is the purpose of Advance MAME?

So then a retort happens that says this.

MAME doesn't produce any video signals. 

So what happens...I get corrected with:

all models of the arcadeVGA and advancemame are capable of sending "true" 15khz signals to an arcade monitor.

How about correcting others instead and tell them to read the wiki??

I was originally asking the question, but it seems that I understood it correct from the beginning which is MAME behaves like a PCB when paired with a graphics card, so the end result can be what Arcade VGA offers...either true 15khz signal or scalled 15khz signal to a PC Monitor.

Which goes back to my first post, yeah...Arcade VGA can do a 15khz to 31khz conversion.