NEC DM-2600P info needed....

[dmarcum99]

On to the issue at hand.  I bought a monitor in Indy from a nice fellow....a NEC DM-2600P.  He said he had it hooked up to his mac as a computer monitor and no longer needed it  He said it should hook up to a PC and would give me a BNC-to-VGA cable.  I jumped on it...drove to Indy to find the monitor sitting in the driveway (not a good sign).  I paid the guy $20 for it picture unseen as he said he was taking the family to grandmas.  I get it home and it has a wierd RGB interface....a 34 pin connector like a floppy cable connector.  The guy gave me the cables he had...and I can get a picture, but it's not perfect.  I'm hoping  anyone here has any experience with the monitor and could tell me if this will do 15K.  I attempted, but the picture would not sync...perhaps I need different cables.

From the TV...the connection goes as follows:
34 pin connector coming from TV and end of this connector is a 4-plug BNC connector.  
Connected to this is a 4-plug BNC connector to VGA connecting to my video card.

On to the advice/info needed.  As I mentioned earlier, the picture is not perfect.  I have vertical scrolling that I cannot control.  Even after a couple of minutes of stable picture, it will begin to roll.

The picture is OK, but it is squished horizontally.  I cannot get the pic to extend to the edges.

Lastly, since this was a broadcast monitor, I thought it would do 15k resolutions....but when I try Donkey Kong or Pac Man, it doesn't sync and I see the colors, but the picture cannot be made out.  I'm using Soft15k... perhaps the connectors are wrong...?

[MonMotha]

Pictures of the input connections available would be handy.  It's possible that there are other connections available that are more suited to your use.

Since you only have 4 BNC connectors, the monitor is probably expecting composite sync.  Ensure that your PC is set up to output this.  You may need to try both polarities (positive and negative).  Arcades usually use negative composite sync, but other industries pick other things.

Everything else just sounds adjustment or connection related.

[dmarcum99]

Thanks MonMotha...I'll post pics and make sure my ATI 4200 is set for composite sync when I get home from work tonight.

[dmarcum99]

I set the ATI catalyst software to have the video card to composite sync and the picture finally stopped rolling!!  YES!!!  The picture is noticeably better now.  I did have options to set the sync's to + or -....I am such beginner I didn't know which to select.  I tried some different settings but didn't notice any difference.  Small VICTORY!!!

On to the horizontal squish...after getting the composite sync set up, I was hoping the horiz squish would be solved...but I was hoping for too much.  Still have it and haven't found any adjustments that would work.  Again, I'm still green on this stuff so maybe there's something I'm missing.

Here's the pics about the back RGB connector and the horiz issues....

[MonMotha]

Is the picture actually that overly bright and blooming at the edges, or is that just due to the camera overexposing the image?

As for the width, check if there's a menu or set of controls to adjust.  If not, you'll have to see if you can remove a LOT of blank area using software (CCC MIGHT let you do this), otherwise you'll probably have to open 'er up and adjust the horizontal width coil.

That connector is something I've never seen used for this purpose.  Looks like a professionally made breakout cable, though, so apparently it was at least somewhat popular.  I don't see any other options for RGB input, unfortunately.

[dmarcum99]

the camera is the fault of the blooming picture.  Actually, it's quite nice....I have a zenith C27v36 as a candidate if I can't sort out the NEC's issues and at default the brightness is scorching.  I'd rather not use the zenith if I don't have to as the pic at 640X480 is so much better than the zenith...

Well, I just spent the last hour trying to adjust the horiz width coil....no go.  I was able to turn the hex key in any direction for as many turns as I wanted and got no response. 

Would this suggest the horiz width caps are bad or the coil? or both?

[Jack Burton]

Try these things in this order

-Does your monitor have a control panel on the front, does it have a H-width option?

-what refresh rate are you running this monitor at?

On all my studio monitors the screen will start to squish more and more towards the center as you increase the refresh rate.  You might try to see if you have it set to 75hz and change it to 60hz and see what happens.

-You can probably also use the ATI control center to increase the horizontal range of the image.

-If all else fails you can use Advancemame and it's ADVV utility to set up a custom back and front porch for your monitor, and fit the image that way.  I had to do this with my Mitsubishi AM-3501R.  I could never get the image to move far enough over to the left.

Once you set the image in ADVV you can copy the resolution out of the ini files in advancemame's directory, and set up soft 15khz to use them all the time so you aren't limited to only using advancemame for emulation.

[dmarcum99]

good advice....I'll look at the monitor's refresh rate when I get home.

The monitor does have a H-width knob on the front panel...and it's adjusted all the way out.
I used the ATI control software to expand it as much as it would allow.  It did help, but not much.

If all else fails, I'll get advancemame and try to make the adjustments you suggested.

[I/O]

Have you run the range of standard game resolutions (including vertical display games in vertical mode) to see how each displays?

[dmarcum99]

Well I'm stumped......

For grins, I hooked up my soft-modded xbox(original).  I hooked it up through s-video and wouldn't ya know.....IT PLAYED FULL SCREEN!!

When I go back to the RGB input, the squished sides are there.  For Vertical gaming it's not an issue, but the horizontal games are losing 1.5-2.0" per side.

I guess I'll have to read up on advancemame........

**edit** I almost forgot...while in windows I am unable to change refresh rate....it's stuck @ 60hz

[Jack Burton]

Strangely enough, on my monitor when I hook up the S-video it looks fine, but if I do RGB SCART input through my PS3 I cannot squish the screen enough for it to fit everything in in.  I always have about 10% cut off, and it's offset largely to the left.

Not really helpful info, but just letting you know that strange things happen when we try to combine technologies together that may be compatible on paper, but slight differences in purpose and design can cause problems like this.

This thread on shmups is relevant: http://shmups.system11.org/viewtopic.php?f=6&t=30640

This post is especially relevant:

Composite video takes a some time to process and turn into RGB for the picture tube. The video sweep is compensated for this so the picture is in the centre.

RGB video over SCART usess composite video for sync, the sync follows the same signal path as it would for a composite video only signal. RGB video doesn't need decoding, it's switched right into the RGB video amplifiers which drive the picture tube. The delay to accomidate the decoding is still there and the video information arrives too early.

It's a silly design fault, basically. A well designed TV/Monitor wouldn't do this...

If you're good at building electronic circuits then you might want to try this:
http://members.optusnet.com.au/eviltim/ ... tysync.png

I think you can also buy video processors which have a shift feature.

In your situation it's like there is some extra circuitry that is used to center and size the picture correctly that is being bypassed via RGB, but is there for S-video.  

What you can probably do is alter the video signal using Soft 15khz, advancemame, or Powerstrip to compensate for this.  

Before you do any of that though, you should also look on your monitor to see if it has an overscan ON/OFF functionality.  This is a feature that most professional monitors have that automatically shrink the image size to allow you to see the parts of the image that are usually in the overscan area of a television signal.  If you have this turned on you will be unable to get a full screen image, even with the H-width turned all the way up.  

It's even conceivable that this is a function that is achieved via a pin on that RGB connector that you have.  It may be neccesary to short a pin on that cable in order to tell the monitor to turn the overscan OFF.  See if you can find a pinout for that connector.

[dmarcum99]

Thanks for the advice!  As luck would have it, the guy who I bought the monitor from emailed me and told me he had the manual to the monitor.  He's mailing it to me and I should have it by weekend.  I'll give it a read and see what the deal is....The picture is so nice on this set and it was made in 1989!!  I just wish I could get the screen to the edged of the tube.   

On a side note, I installed advancemame in my cab last night and I gotta say that I believe the picture coming from advancemame was superior to the picture from mameui.  Granted, I still had the squish, but the difference was noticeable.  Is there a reason I saw a difference?  Was advancemame choosing different resolutions?  Has anyone got advancemame to run with Hyperspin?  Are there any popular games that I'd miss if I kept advancemame @ .106 instead of the current mame builds?

[Jack Burton]

MAMEUI by itself hasn't even begun to tap the potential of this monitor if it supports 15khz modes.

Advancemame usually chooses a resolution that is compatible with your current registry settings and is closest to the game.  So it's possible that advancemame was using double resolutions, and those would certainly look better than what MAMEUI and Direct3d puts out.  

Just wait, man, you ain't seen nothing yet.

There's not much you would miss.  There are actually even some unofficial advancemame builds that include new games like the CPS3 and later Neo-geo games. 

One thing I wish advancemame had was proper discrete sound emulation for Donkey Kong,

BUT

it's possible to use advancemame resolutions with regular MAME!  But before you even attempt something like that you should try to fix your squished image problem first. 

[dmarcum99]

OK...I got the manual from the guy from Indy.  It's H freq range is from 15-35.5hz and the V freq range is 50-87hz.  

I made a PDF file of the RGB pinout. I also downloaded a diagram of a VGA pinout.   Maybe the RGB-to-4BNC-to-VGA is the culprit...?  If I wanted to make my own cable going straight from VGA TO RGB I will need some help on a few connections.  Any help would be great.  Also any advice against me making such a cable would be welcome as well.

Also, I have 2 adjustable pots in the front that I haven't used yet.  I didn't know what they were so I didn't touch them.  SUB T......and SUB C........my owners manual only states that these are "Serviceman control"....any ideas?

[dmarcum99]

Well last night I thought I was going to make some headway but it was uneventful.  Looking over the 34pin piut diagram on my NEC DM-2600P, I noticed that the composite ground wire was connected to the BLUE TTL pin on the monitor.  I changed that(connected to ground), but got no improvements.  

So I got frustrated and opened the back of the unit and started turning every pot I could find.  I found one that would shrink the horiz, but could not expand it any more.    

At first I thought it was going to need a cap kit, but I found out I got a full screen picture while connected to s-video...  

This monitor can accept both separate H & V sync signals and composite.  Since I am using a 4-wire BNC cable it's feeding a composite synch.  Would it make a difference if I fed it separate H & V syncs?

I should have mentioned this earlier...but I am using the on-board ati4200 video.  Would this have any affect since this is such an old monitor?

Also, it was mentioned that I might need to adjust the front and back porches....?  Could someone expand on that so I could get an idea what that is about and possibly some links for me to go for help??

[dmarcum99]

I'm starting to think it's my video card not playing nice with the monitor.  I just read from easymamecab tutorial that if my "pclock" on my video card isn't right, then my monitor could over/underscan...

http://easymamecab.mameworld.info/html/monito10.htm

So....tonight I'm going to put in my ati 9200se PCI video card and see it it helps.  At least I could try to use the advcfg utility as this card is supported.  I hope it helps....but at the same time this is kinda sucky.  I bought the mobo with ATI4200 on-board so I wouldn't have to worry about a separate video card.  At least I found some XP64 drivers....on ATI's site I can't find XP64 drivers for the 92XX series cards....

[Jack Burton]

it's certainly possible, and you can change the pclock via advv if neccesary on the current card in your setup. 

but let's see what happens when you switch before we do that. 

[I/O]

I should think the BNC to interface you have is adequate. Are you sure you're running games at 15khz?

[dmarcum99]

It was the VIDOE CARD!!!  AAHHHAHAHAHAHAAHAHAHAH!    

Now since I messed with EVERY pot on the boards I now have to go back and try to dial the picture in as I introduced geometry issues.....   

I'm not sure how it happened, but now I have some convergence issues.  Well, I'm lying....I do know how it happened but I'm not supposed to tell anybody. (shhh...secret)  The rings on the neck were loose and I bumped them while adjusting pots on the chassis.....   

1) Does anyone know where I can get a 640 X480 convergence pattern screen?  I tried to use the program in the downloads section, but it says it's not for this program....I'm using XP64.

2) Would anyone know why I couldn't get "advcfg.exe advmamec" & "svgawin.exe -l" to work?  I thought since I used a card that was on the compatibility list (ati 9200SE) that I could get these program to work.  For svgawin, I got a message that the driver was installed, but when trying advcfg, I got the no hardware installed message.  Would XP64 be the problem?  I only found one XP64 driver...and it wasn't signed.  It was a beta 6.6 catylist driver package.  Mameui was a little glitchy with the 9200SE/catylist 6.6 beta combination...

The good news is that I'm close...really close to be able to use this monitor to it's fullest.  Sometimes I wonder if the XP64 thing was such a good idea as I keep running into roadblocks.

[MonMotha]

Given that XP64 is totally unsupported/end of life due to lack of SP3, I'd question its usage.  It was never well supported anyway, especially wrt driver availability.

The reason your program is probably saying it's "not for this operating system" or whatever the error is is because it's probably a 16-bit Windows app (i.e. for Windows 3.1).  64-bit Windows drops support for that.

Convergence is usually just set using a white grid pattern.  The Nokia monitor test application can probably generate one of this, or you can just load up MAME and use any one of the many games that have such a pattern in their test mode.

[Jack Burton]

I use nokia monitor test for my convergence tests. 

http://www.softpedia.com/get/Multimedia/Video/Other-VIDEO-Tools/Nokia-Monitor-Test.shtml

I would definitely uninstall XP64 and get everything running on 32 bit windows before I even tried to get stuff on 64 bit. 

[dmarcum99]

UPDATE:
I went from 64bit XP to 32bit.  I was able to get better drivers and manage the screen.  This was great news.  I wasn't able to use the advcfg or advv programs....but that wasn't a big deal.  I was able to get the games to play full screen in their native res.  I was going to make a cable going directly from VGA to the 34 pin connector.  Using H & V sync compared to composite will keep my screen from rolling at bootup.  BIG PLUS!!!

But alas, for me, the journey for this monitor has come to an end.  I scored the best deal yet.....I went from using a Sony 24" WEGA on component -to- 27" VGA monitor -to- NEC DM-2600P to the grandaddy of them all... the XM2950.  I found a kid on craigslist selling the XM2950 for $80.  I was able to talk him down to $60 and it has the remote.  So, my total investment for my cab's monitor(s)comes in at $150.  The picture is just fantastic.  The DM-2600P and the XM2950 are very close in comparison...  I can't wait to get it in my cab.  My only concern is decasing it.  With case, it's 25 3/8" wide and my cab's monitor opening is only 25".  With so many boards on this chassis, this will be a challenge for me.

It anyone in the cincy area wants to buy the DM-2600P just PM me.  $35 takes it to BYOAC'ers.  You also get the parts to make the custom cable.  It was a nightmare to find another 34 pin connector.  I guess I could have used a floppy connector in a pinch, but who wants to go sloppy?  The DM-2600P is a great monitor, it just now needs a little time spent to dial the picture as a result of my troubleshooting.

If anyone is interested in the sony 24" WEGA, it is for sale too...it's de-cased and has a custom wood mounting panel for the 25" midway cabs...$20 and it's yours!