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Neo Geo MVS, incompatible with SuzoHapp CGA LCD?

Kujako

Kujako

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So pulling my 25" CRT from my MVS "big red" so that I can work on it, planned on putting in a 19" SuzoHapp CGA/VGA LCD for the time being so I can keep using it. Now this cabinet has a JAMMA switcher and seven different arcade boards in it, including a MVS-2F and MVS-1B. Wiring is still MVS, using adapters for the JAMMA boards. I hooked up the LCD outside of the cabinet to test, and all boards work EXCEPT the two Neo Geo's. On both of those, I get no signal.

Any ideas? Again, works with a Sega 16b, CPS2, Sega STV & PGM. Not working with Neo Geo MVS (and it looks like also not working with a Namco 256, not tried any others).

I can try using the VGA port and 31khz with the devices that support it, and I guess I could scale CGA to VGA... but this is supposed to be temporary. So there's limits to what I want to try.
 
Neo-Geo is an odd duck, not as bad as say the Midway family of PCBs...
But yes even on the OSSC it required "special" pre/post coast settings to lock a sync.

I have heard of an old work around...
Bypassing the off-spec sync using the sync pin from the GPU, and with a 480ohm resistor connecting it directly to the sync pin on the edge (cutting the original trace).

PLEASE do proper research IF you want to attempt this, I've never personally done it (and I'm speaking from memory/smoked pot almost daily for the past 30 years). ;)

Maybe @XianXi could go into further detail.
 
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jassin000 said:
PLEASE do proper research IF you want to attempt this, I've never personally done it (and I'm speaking from memory/smoked pot almost daily for the past 30 years). ;)
Click to expand...
Yeah that would be way beyond what I'm willing to do for this. Plan is still to get back to the CRT, but after the second sprained finger trying to fiddle around inside the cabinet I've opted to pull the CRT frame out and get it running on a workbench. The LCD is just to tide me over (and perhaps for another project later). I've got an old GBS 8200 I may try, if that circumvents the issue I'll consider doing the whole "GBS Control" thing to it. But definitely no modifications to the arcade boards, only willing to do something that can be run inline between the RGBS and the LCD. I mean, WORSE case I can just not use the Neo Geo or other boards that don't work... but that would make me sad (also haven't tested my CPS2 & 3 multi, Naomi, etc. So others may have issues as well). Only issue is I don't have a wiring harness for the GBS that'll work... but that seems more manageable. Can probably jury-rig up something to at least see if it'll work.
 
I guess that GBS control project is OK, can't be worse than the device stock thats for sure (like so many of the devices I deem junk I gave mine away).
I still say the OSSC with a freesync monitor is the way to go, supports EVERYTHING (with proper settings/configuration)!

Doubtful you'll have any issues with CPS1/2 if you've gotten ANY other 15khz stuff working.
Naomi being a 31khz system native, I would think it a total non issue (unless that LCD ONLY dose 15khz, but then just flip the DIP).

GBS? Its pretty... pretty... pretty... OK.
70047_v9_bb.jpg


heh
 
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jassin000 said:
Naomi being a 31khz system native, I would think it a total non issue (unless that LCD ONLY dose 15khz, but then just flip the DIP).
Click to expand...
True, I guess I can run the JVS stuff to the 31khz VGA. As for using an OSSC, I'm far too lazy. I opted for a RetroTink2x for my consoles. From what I've seen, the GBS-Control does a good job of making the device more usable. But so far I've only determined that mine doesn't blow up when plugged in after all these years.
 
Kujako said:
As for using an OSSC, I'm far too lazy.
Click to expand...
Sure it takes work to setup everything, but then you just save a profile (0~9) to the SD card and you never have to screw with it again.
Objectively (because I <3 OSSC) the biggest issue is monitors that won't display anything but 60hz (making that freesync LCD pretty much a requirement for use/NOT optional).

OSSC = 180$
Custom VLX LCD mounting bracket = 200$
32" LG freesync LCD = 450$

So basically almost 1K to "upgrade" a Vewlix (and we haven't even gotten into the Jammifier cost yet). :S
 
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jassin000 said:
Sure it takes work to setup everything, but then you just save a profile (0~9) to the SD card and you never have to screw with it again.
Objectively (because I <3 OSSC) the biggest issue is monitors that won't display anything but 60hz (making that freesync LCD pretty much a requirement for use/NOT optional).

OSSC = 180$
Custom VLX LCD mounting bracket = 200$
32" LG freesync LCD = 450$

So basically almost 1K to "upgrade" a Vewlix (and we haven't even gotten into the Jammifier cost yet). :S
Click to expand...
Sounds nice, but way more involved than I can justify at the moment. Perhaps if I ever track down a candy cab in my area... but for now, it seems that the wiring harness I made for the GBS out of staples and cheap alligator clips isn't working (shocking I know). I'll have to track down some 0.156 pin male connectors and try again. Any chance you know what the pitch is on a CGA ten pin connector (guess I can just measure it).

IMG_0844.jpg
 
OK, so following up. Tried to jury-rig a harnnes again, using copper wire rather than zinc coated staples (must have been really tired to have thought that would work) and the GBS does indeed handle the sync signal from the Neo Geo MVS. So looks like that's the solution for me. Will source the parts for the GBS Control mod, which will address the latency and "softening" effect the GBS scaler has. A bit of wavy lines at the top of the image, but that can be compensated for if it persists after the GBS is upgraded (I think this artifacting is the reason the MVS failed to sync to the monitor in the first place. Could be wrong through).
IMG_0845.jpg
 
Does that monitor have V-size and H-size controls to allow for games that used non-square pixels?

I can't fully see in the photo but it looks like the wavy lines at the top are the ones that are meant to be there. They'd just not be visible on a CRT as they'd be clipped by over-scan.

I assume they must have a way of making games fill the screen?
 
Zebra said:
Does that monitor have V-size and H-size controls to allow for games that used non-square pixels?

I can't fully see in the photo but it looks like the wavy lines at the top are the ones that are meant to be there. They'd just not be visible on a CRT as they'd be clipped by over-scan.

I assume they must have a way of making games fill the screen?
Click to expand...
Yeah it has V/H position and size controls, as well as digital RGB adjustments. It is made for use in arcade machines and has everything that would be expected from that (despite the sync issues with the built in CGA to VGA scaler). The arduino controller should arrive today (had to buy three, cause they're too cheap for people to sell just one), then should be able to get the GBS upgraded.
 
That's a strange approach on their part (I mean Happ).

Stretching an image to fill the screen on an LCD is just more scaling. It's not like the analog stretch on a CRT where you change the shape and size without changing the resolution.

Even the best scaler in the world wouldn't help if you add bad scaling on top of good. I would have thought it would have made more sense to have the scaler output all games at the monitor's native res.

Does it make the image softer when you use the v-size and H-size controls?
 
Zebra said:
That's a strange approach on their part (I mean Happ).

Stretching an image to fill the screen on an LCD is just more scaling. It's not like the analog stretch on a CRT where you change the shape and size without changing the resolution.

Even the best scaler in the world wouldn't help if you add bad scaling on top of good. I would have thought it would have made more sense to have the scaler output all games at the monitor's native res.

Does it make the image softer when you use the v-size and H-size controls?
Click to expand...
Yes, the built in scaler isn't great (though I was not able to detect any latency). It's definitely not as sharp as I would have liked. From what I've been able to read/review online, the modified GBS running to the VGA input rather than the CGA input on the Happ LCD should work better. Guess I'll find out.
 
Luckily it's only temporary and hopefully it will just make you appreciate your crt even more when it's fixed.

Arcade scaling is a tricky issue with there being so many obscure resolutions. An algorithm that looks OK upscaling 240p to 960p for 1080p and 4k monitors might not be so great for 256p games or for 1024p or 768p 4:3 arcade LCDs.

Will the modified GBS have different settings for all the different arcade resolutions?
 
Zebra said:
Luckily it's only temporary and hopefully it will just make you appreciate your crt even more when it's fixed.

Arcade scaling is a tricky issue with there being so many obscure resolutions. An algorithm that looks OK upscaling 240p to 960p for 1080p and 4k monitors might not be so great for 256p games or for 1024p or 768p 4:3 arcade LCDs.

Will the modified GBS have different settings for all the different arcade resolutions?
Click to expand...

It should, and will use the WiFi of the Arduino to allow configuration change from a web interface. Was going to work on it this weekend, but then I got tired...
 
Kujako said:
The GBS Control web ui allows saving presets, so I should be able to tweak things for the different boards and then quickly load the saved preset.
https://admin.retrorgb.com/wp-content/uploads/2021/03/GBScUIv2-scaled.jpg

Got the arduino setup, now just need to do the soldering.
Click to expand...
That's awesome if it has different scaling algorithms that are optimized for each game. I don't know of any other options that are so versatile.

I love that people are doing diy and open source scalers using commonly available and inexpensive hardware these days.

Decent scalers have historically been outrageously expensive. Those OSSC guys have done the world a solid by kicking down that door.

I might check it out to see if DVDs still have a place in my home theater room.
 
I don't want to downplay the fine work in this thread....
But let it be known this Suzo Happ LCD is NOT a good option for 15khz games, likewise pairing it with a GBS.

I don't think I need to go into all the reasons why (should be obvious and I'm trying to keep this "polite" for a change). ;)
 
GBS-CONTROL is pretty damned nice. I bought a GBS just to play with it and see what it could do with an arcade board...namely a CPS2 board. I already had an OSSC,
so the GBS was not to be my "go to" connection to a 31KHz monitor. The default GBS is garbage...I was getting all sorts of artifacts, sparkling, etc. Well, that all changed
after modifying it with the GBSControl hardware. No more artifacts, no latency I can see, scanline simulation that looks just as good as that of the OSSC, IMO, and web based control
of settings. I'd recommend at least trying it out. Someone is even selling a kit on eBay that allows you to make the needed connections to the PLCC without having to solder to it.
 
jassin000 said:
I don't want to downplay the fine work in this thread....
But let it be known this Suzo Happ LCD is NOT a good option for 15khz games, likewise pairing it with a GBS.

I don't think I need to go into all the reasons why (should be obvious and I'm trying to keep this "polite" for a change). ;)
Click to expand...
Oh I know, I went with a cheap option because it's only going to be used while I work on the CRT (think I paid like 125$ for the LCD). Had it mostly worked I'd have been happy enough, but as it failed to sync to the Neo Geos I'll have the opportunity to do the GBS Control thing given that I had a GBS 8200 collecting dust and the rest of the parts are cheap. From everything I've seen, it's a massive improvement over the stock firmware. It's also kind of interesting to me as none of the reviews or write ups I've seen for it approach using it for arcade systems. If it works well, I may pair it with a better LCD down the road, or build the current one into a bar-top.
 
I dub it, the "thingamabob". No idea if it works yet, but it passed the smoke test. Since the LCD runs off 12v, and the GBS can run on 5-12v, I added a buck transformer to step down the 12v I'll run the GBS off of (using a y-cable to the LCD) to 5v to power the arduino.

IMG_0846.jpg
 
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