HDMI -VGA Direct Out to Arcade Monitor Help

[Sirsalt]

I've searched for hours and can't seem to find any definitive information on the settings/wiring to an arcade monitor (19" Well Gardner 4900 CRT). There seems to be detailed accounts of every type of CRT via the HDMI to VGA cable except arcade monitors. Most videos and posts on the subject seem to very light on how things are hooked up on the arcade monitor side. I'm not having any luck, and I'm sure I'm missing some key information. Below is my setup.

Hardware
- Mister
- Rankie HDMI to VGA adapter (purchased the one linked on RetroRGB)
- Custom VGA to Arcade Monitor cable (Made by me per VGA pinout standards)

Mister Configuration (Mister.ini)
a) direct_video=1 and composite_sync=1 (No activity on arcade monitor)
b) direct_video=1 and composite_sync=0 (No activity on arcade monitor)

The #1 question I have is, how should the sync be wired on the arcade monitor side? I've owned over 100 arcade machines over the years and have rebuild over a hundred monitors during that time as well (I used to own a retro arcade). I've rebuilt, fixed and restored over 100 arcade machines over the years and there always seems to be some crazy problem that needs to be solved... When connecting a monitor to a game, there are many different ways the sync should be wired depending on the game. I can't find any information as to how people are wiring the sync on the arcade monitor side when setting up the MIster. Below are the pinouts from the VGA side of the Rankie HDMI top VGA adapter and the available pins on an arcade monitor:

- Rankie Adapter VGA out: R G B Ground H-Sync V-Sync (Total of 6 Terminals)
- Arcade monitor input header: R G B Ground H-sync V-sync (Total of 6 Terminals)

Arcade PCB"s normally only have a single sync wire that connects to either the V-Sync, H-Sync or ties into both the V-Sync and H-sync There's never a separate V-Sync and H-Sync coming from the arcade PCB that connects to the V-Sync and H-Sync on the arcade monitor. MY question is, how am I supposed to wire the arcade monitor input header? I've tried every combination and get absolutely no activity on the Arcade monitor. I verified my arcade monitor is good by running my test pattern generator on it, and it looks great.

I made my own VGA to Arcade monitor cable and wired it per standard VGA pinouts. I verified my wiring around the 5 grounds and all are wired correctly per VGA standards.

I've run out of scenarios to test and would appreciate any help. I'm hoping I just missed a step or configuration somewhere...

Thanks
-John

[Tulius]

Wouldn't be easier if you just buy an analog io-board for Mister and direct connect a VGA cable to the monitor? With this board is just plug and play because you're connecting a VGA PC and not a consumer CRT TV.

[akeley]

Did you see this: https://www.retrorgb.com/mistercade-ins ... rview.html

[FoxbatStargazer]

Any HDMI->VGA adapter is going to default to RGBHV output. csync=1 should combine the syncs into one, but I'm suspicious whether all hdmi adapters support passing through the combined sync from the Mister.

The other thing I would check is voltages, arcade monitors often demanded different values than the 0.7 v RGB that is standard for VGA, as well as the 5 v TTL sync. I would also try some other device besides Mister with your cable to confirm that it is put together correctly.

[callanabrown]

Hi! I'm also using a K4900 so I can help.

I'm using a HDMI->VGA, then an Ultimarc VGA amplifier (https://www.ultimarc.com/arcade-vga-and ... amplifier/) which gives you screw terminals. Then I got to the K4900 with RGB, composite sync and ground. In my MiSter.ini, I have it set to direct video and composite sync enabled.

I personally found the video to be much too dark without the Ultimarc amplifier. I highly recommend adding it into your chain. It does need a little mod because it expects 5V over the input VGA, which your HDMI->VGA cable won't provide. I just spliced in another microUSB cable connecting only the 5V and ground.

You mentioned "no activity on arcade monitor". No activity means there must be something off about the HDMI adapter. Regardless of sync, you should get color on the arcade monitor if any of the RGB signals are working. Are you powering the HDMI converter with the microUSB cable? This is necessary.

Another question - did you wire all the grounds on the VGA cable together? I have some memory of needing to do that. VGA has a ground for each color.

[Sirsalt]

Thanks for the help everyone. I'm going to run some tests now and see if I can iron out the issue. I'm close...

Did you see this: https://www.retrorgb.com/mistercade-ins ... rview.html

I did see this. From my experience, once you start adding boards between the original outputs it ends up adding lag. I'd rather go with the straight through connection of the HDMI to VGA, and add my own zero delay controls via USB. A lot cheaper going this route as well.

Any HDMI->VGA adapter is going to default to RGBHV output. csync=1 should combine the syncs into one, but I'm suspicious whether all hdmi adapters support passing through the combined sync from the Mister.

The other thing I would check is voltages, arcade monitors often demanded different values than the 0.7 v RGB that is standard for VGA, as well as the 5 v TTL sync. I would also try some other device besides Mister with your cable to confirm that it is put together correctly.

I'll give that a go. Looks like I also need to add the 5v micro USB to the Rankie as well. Good stuff, thanks for the help!

Hi! I'm also using a K4900 so I can help.

I'm using a HDMI->VGA, then an Ultimarc VGA amplifier (https://www.ultimarc.com/arcade-vga-and ... amplifier/) which gives you screw terminals. Then I got to the K4900 with RGB, composite sync and ground. In my MiSter.ini, I have it set to direct video and composite sync enabled.

I personally found the video to be much too dark without the Ultimarc amplifier. I highly recommend adding it into your chain. It does need a little mod because it expects 5V over the input VGA, which your HDMI->VGA cable won't provide. I just spliced in another microUSB cable connecting only the 5V and ground.

You mentioned "no activity on arcade monitor". No activity means there must be something off about the HDMI adapter. Regardless of sync, you should get color on the arcade monitor if any of the RGB signals are working. Are you powering the HDMI converter with the microUSB cable? This is necessary.

Another question - did you wire all the grounds on the VGA cable together? I have some memory of needing to do that. VGA has a ground for each color.

The link to the amplifier really helped. It explained connectivity on the monitor side very well, which does translate to wiring the mister directly with my cable. Also, I was not using the 5V micro USB connection on the Rankie. When I did, setup the "old" way I was doing it, I did get picture on the monitor, but it was all wacky out of sync. So I'm pretty sure my cable is good, I just need to iron out the sync issue.

[Sirsalt]

Getting closer... Any suggestions?

I get the same issue with "composite_sync=1 or composite_sync=0. Only difference with this setting is how the sync wires are ran to the arcade monitor. So I at least proved that the arcade monitor will work with csync set to 0 or 1, you just have to wire it differently on the arcade monitor side. So now I have an issue that I don't think is related to the HDMI to VGA setup. I did some searching on the web for this issue in general, and found an instance where an arcade game running under windows did this, and it was a driver issue, which leads me to believe there may be an issue with signal being sent from the mister. Possibly resolution? Which doesn't really make sense, as the direct out=0 is supposed to send the native core signal out...

Any suggestions? I'm out of ideas for the moment.

20220616_020515[1].jpg (6.02 MiB) Viewed 3147 times

[callanabrown]

So from your custom cable, how did you deal with sync? Did you wire H and V from your connector to H and V on the K4900? Like you said, most (not all) arcade boards use composite sync. When you set composite_sync=1 in your MiSTer.ini, you get composite sync on the H pin from the VGA connector, which you can connect to both the H and V pins on the K4900.

For anyone not familiar with arcade monitors, it would seem weird to connect composite sync to both H and V inputs on the monitor, but this is how it's done.

Regarding your problem, it's a little strange that it seems to have the horizontal sync working but starting in the totally wrong part of the screen... Is it possible you hooked up to positive sync on your k4900? Sync from the MiSTer is negative sync.

From back to front the pinout is:
R
G
B
GND
+V
+H

GND
-V
-H

[Sirsalt]

Regarding your problem, it's a little strange that it seems to have the horizontal sync working but starting in the totally wrong part of the screen... Is it possible you hooked up to positive sync on your k4900? Sync from the MiSTer is negative sync.

I believe you nailed it. I'm connected to positive sync. I'm at work now. I'll give it a go when I get home.

Didn't even think to move over to negative.

Thanks!

[Sirsalt]

Moved to negative sync and good to go!

20220616_214437.jpg (8.54 MiB) Viewed 3080 times

I personally found the video to be much too dark without the Ultimarc amplifier.

callanabrown, I see what you mean about how dim it is. The pic makes it look nice and bright, but that's just my phone boosting the contrast. Is there a way to boost the signal without using the amplifier? Can I I just run 5V to pin9?

-John

[callanabrown]

Hi John, great!! Glad I could help. Yes whatever way you do it you need to get 5v to the amp. I'll post a picture of my arrangement shortly.

As far as skipping the amp altogether, I thought I could get away without it just by using the various neckboard controls, but in the end I concluded it was necessary for at least this model.

Anyone else using a MiSTer with a vintage arcade monitor care to chime in? K4600, K7000, G07 etc?

[Sirsalt]

Hi John, great!! Glad I could help. Yes whatever way you do it you need to get 5v to the amp. I'll post a picture of my arrangement shortly.

As far as skipping the amp altogether, I thought I could get away without it just by using the various neckboard controls, but in the end I concluded it was necessary for at least this model.

Anyone else using a MiSTer with a vintage arcade monitor care to chime in? 4600, K7000, G07 etc?

Ya, I've gotten pretty good over the years adjusting monitors, and no matter what technique I use, I can't get the normal "pop" you usually get with a monitor. I was wondering what would happen if I pump up the B+. That will usually knock the brightness up, but at the cost of possibly overdriving the monitor. I'll get the amplifier if I have to, but hoping I can come up with a safe alternative.

My next step was to try with other models to see what happens. I currently have some 19" k7000 & GO7. This was just a proof of concept. My end goal is to setup a cab with a 25" K7000.

I'll update what I find here, as I go.

[FoxbatStargazer]

That's what I was getting at with the RGB voltage. Usually the specs are in the manual that will tell you the "peak-to-peak" voltage which gives the max value. Then you just get an amplifier to match that.

I spent a while trying to figure out how to get an Atari ST monitor hooked up to Mister. Its RGBHV and finding a custom cable wasn't hard, but the image was fairly dim. The specs indicated that the RGB signals were supposed to max at 1v and I noticed that the Mister output 0.7. I tried out an extron P/2 DA4xi because it had a switch on back for amplifying VGA output to 1 v and it fixed my problem 100% and now was the same brightness as a real Atari ST. So you just need to look up the RGB voltage peak-peak values in your monitor and amplifier and you should be able to amplify safely.

[Sirsalt]

Anyone else using a MiSTer with a vintage arcade monitor care to chime in? K4600, K7000, G07 etc?

How are you getting sound? I tried connecting speakers to the auido port on the HDMI>VGA, and I just get buzzing.

-John

[callanabrown]

You need an amplifier. I use a Lepy from Amazon.