Advancemame users: sync polarity parameter?

[Ummon]

Does anyone know what the parameter in Advancemame is for switching the sync polarity?

[Ummon]

This is the passage in the 'install' doc:

If the monitor accepts a composite sync signal, instead of using a sync conversion circuits you can also try twisting the two H and V VGA signal together. It works if you select VGA negative H and V sync on the programs.

Okay, and what is this? I know that putting a '-' or '+' by the h/vsync in a modeline can affect this, but I'm looking for a global effect.

[NickG]

This is the passage in the 'install' doc:

If the monitor accepts a composite sync signal, instead of using a sync conversion circuits you can also try twisting the two H and V VGA signal together. It works if you select VGA negative H and V sync on the programs.

Okay, and what is this?

It changes the sync polarity.  If your monitor video processing circuits can accept either polarity of signal then it should not change anything.  If your monitor is more "finicky", it may cause rolling or a slightly shifted over and/or down image.  If you are using a composite (or twisted) sync line then you should probably match the polarity of the sync, and try both H and V as negative first, if your picture is rolling. 

Edit: technically you should try to hunt down your monitor specs before going about a trial and error method, so as not to cause damage...

[Ummon]

<edit>

[Ummon]

I meant, what is this parametre to be entered in the rc file? He seems to refer to one and then doesn't say what it is. I get Windows and Mame by wiring the contacts together and doing nothing else.

[tikbalang]

the parameter you are looking for is the modeline created by advcfg.exe or advv.exe. you will still need these two:

device_video_clock
device_video_format

from your monitor specs.

once you test and select working modelines, it will be added into your .rc file. you can force modeline usage with:

display_mode auto | MODELINE_NAME

i don't use this method.

[Ummon]

I've thought about all that. In the first part, I get the same scrambled picture when selecting '15khz starndard resolution monitor' in advcfg, so I can't even get a 'format' out of it.

[tikbalang]

i forgot to mention that i'm using a pc monitor with advmame. you also have to consider the capabilities of your video card. there was a time i was using an old 4mb s3 virge agp and the video came out as:

Code: [Select]


[ ]]]]]


or

Code: [Select]


[ ][ ][ ]
[ ][ ][ ]


where [ ] = one screen. i don't know what kind of error it was but the game screen is multiplied depending on its resolution. i swapped the s3 card with a 2mb ati pci and it worked with no speed losses.

the list of vidcards in the docfiles are outdated. if you want, you can try lincade.

[Ummon]

I'm using the Windows version.

[Ummon]

Here's a bump. I just can't figure this. I get a stable picture in Windows Mame. But in Advancemame I get a stable, it doesn't roll, yet scrambled picture.

[tikbalang]

try pressing "." or "," (dot or comma) while in-game.

[Ummon]

I found out some interesting things. These buttons just toggle through the list of available modes. For example, if device_video_adjust is set to 'generate_yclock', it's on 'auto', and there is only one mode - the one generated. If it's set to 'none', then it will automatically select a number of modelines available within the bounds of the device_video_format, and hence you can toggle through them, back and forth (the list doesn't roll over).

To test something, I inserted a modeline at display_video, in this case ntsc_320x240. This was then the only modeline available. (I'm not sure why one would want to do this, necessarily, even if using for only one game, when the auto mode is more effective, but...) I noticed the default sync was negative, but I tried it (again) anyways, as well as changing to positive sync. There was no change in the image - neither on this monitor nor the multisync (which displayed either sync polarity fine) I was using to access windows and pre-test things.

I went back to the doc and looked again at what it says about using composite sync:

If the monitor accepts a composite sync signal, instead of using a sync conversion circuits you can also try twisting the two H and V VGA signal together. It works if you select VGA negative H and V sync on the programs. To be on safe side I DO NOT RECOMMEND THIS HACK to connect sync signals directly together. Technically you should never just tie sync signal lines together. They are not usually designed for this, so this can damage your video card. If you try, use with caution.

So maybe I need a sync converter? I didn't want to have to pull the monitor out and run separate sync lines, but it's looking like I'll have to. Anyways, thank you for your assistance.

[NickG]

You shouldn't need any additional circuitry for Advancemame, because you had a stable picture in Windows Mame.
The picture just looks too high sync or too high of pixel clock.  Have you tried the horizontal sync line only trick?

[Ummon]

If I touch the lead to both V and H/C in Windows and Mame, I get the proper picture. (Of course, unless at 15khz, Windows is tri'ed, but it's not scrambled.) With Advancemame, lead on both or only on H/C and it's scrambled and runs. On V it's only scrambled.