- Thread starter Frank_fjs
- Start date
JVS does need 3.3v. So in this case, I didn't terminate any connections on the +3.3v pins off of the JVS power connector. I just pulled +5vdc and +12vdc off of the JVS power connector and am feeding it to the JAMMA edge.
DoktorSleepless
Professional
I thought the Jammafier didn't touch the video signal, it just used the HD15 connector since that's what's in most JVS cabinets. I'd like to be wrong, though. Then I could just plug this thing in instead of waiting for a Jassifier and an OSSC.
I don't know what JAMMAfier does with the video signal. But I do know JAMMAfier sends the video signal down the VGA cable. I know that VGA video is 0.7vpp. Whereas JAMMA video is between 2-5vpp. I know each tri-sync monitor has a high impedence connection for JAMMA video. Then a separate VGA connection.
And lastly, I know that with a JAMMA loom, I am conecting JAMMA video to the high impedence connection on the chassis.
And lastly, I know that with a JAMMA loom, I am conecting JAMMA video to the high impedence connection on the chassis.
DoktorSleepless
Professional
True, but just because it uses the same cable doesn't mean it's using the same signal. I'm not trying to dissuade you from the project, I'm merely attempting to understand it so that I can determine if I'm going down the right path or not with my own cabinet.
That is the point. VGA video and JAMMA video are different signals. That is why I am using a JAMMA loom to send JAMMA video to the high impedence connection on the chassis. The VGA cable in the JAMMA cab is connected to a different (low impedence) connector on the chassis. I would only connect my JVS boards or MAME to the VGA cable in my JVS cabs. Two different signals. Two different cables for each signal. Two different connections on the chassis for the different video signals.
And you aren't dissuading me. I have 3 JVS cabs so economically it doesn't make sense for me to pay for a JAMMAfier for each one. Besides, I like to tinker. Also, I've already created JAMMA looms for 1 of 3 of my JVS cabs. Just working on the other two now.
@DoktorSleepless, so you are right, JAMMAfier doesn't alter the video signal from the JAMMA board. It just sends the high impedence signal down the VGA cable. The VGA cable then of course is connected to the low impedence connection on the tri-sync monitor's chassis.
As for your scenario, you are feeding JAMMA video into a SCART connection. SCART video is 0.7vpp and JAMMA video is 2-5vpp. So use the JASSifier to knock it down to be safe, which is why @jassin000 made it. If I was a Viewlix owner/user, I would fab a JAMMA loom and skip all the other things you have to buy to make playing JAMMA games on your cab possible. But if I were to do that, then first I would have to understand if your monitors has a high impedence connection able to accept un-altered JAMMA video. Maybe it does, maybe it doesn't. But then again, I am not a Viewlix owner/user. So no need for me to cross that bridge.
People tend to say, "just get a JAMMAfier" for your JVS cab to make playing JAMMA PCB's easy. I know JAMMAfier makes the setup simple but there seems to be trade-offs: proper or improper video connection across different monitors as described above, some fractional lag, and I've read of incompatibilities with certain PCB's. Can't beat good ol' copper to copper when using a loom. The only trade-off with a loom is the effort you have to invest to get it going. But then again, you save about $150 too if you fab your own loom.
No idea if the two connections (low impedence for VGA video and high impedence for JAMMA video) on a tri-sync monitor are any different from one another. Or if they are just separate connections and pipe the signal into the circuitry which then processes the levels and other things. Also, no idea if different tri-sync monitors are built handle the signals differently from the two connections or not. All I know is that using a JAMMA loom to pipe the high impedence JAMMA video to the high impedence connection on my tri-sync monitor is proper. Afterall, why would there be a high and low impedence connection on a tri-sync monitor?
As for your scenario, you are feeding JAMMA video into a SCART connection. SCART video is 0.7vpp and JAMMA video is 2-5vpp. So use the JASSifier to knock it down to be safe, which is why @jassin000 made it. If I was a Viewlix owner/user, I would fab a JAMMA loom and skip all the other things you have to buy to make playing JAMMA games on your cab possible. But if I were to do that, then first I would have to understand if your monitors has a high impedence connection able to accept un-altered JAMMA video. Maybe it does, maybe it doesn't. But then again, I am not a Viewlix owner/user. So no need for me to cross that bridge.
People tend to say, "just get a JAMMAfier" for your JVS cab to make playing JAMMA PCB's easy. I know JAMMAfier makes the setup simple but there seems to be trade-offs: proper or improper video connection across different monitors as described above, some fractional lag, and I've read of incompatibilities with certain PCB's. Can't beat good ol' copper to copper when using a loom. The only trade-off with a loom is the effort you have to invest to get it going. But then again, you save about $150 too if you fab your own loom.
J
jassin000
Yea just get a Jammafier for your JVS cab...
But also get/build a Jassifier if you need SCART video levels (OSSC or other SCART based device).
The lag is so low (polling so high) its beyond human perception, not as low/nonexistent as real copper tho you'll never know or feel the difference in game play.
No incompatibility, its just not possible as all its doing is providing power and adapting/encoding JAMMA controls...
That being said because the video is unprocessed you might have issues displaying/using that, but of course this isn't the Jammafier's fault/problem.
Oh I guess for games with alternative/non-JAMMA (ie rotary/trackball) control that would be a problem, but duh (they would be a problem for any pure JAMMA supergun).
Last edited by a moderator:
DoktorSleepless
Professional
Makes sense. Proper connections are important, and if you've got 'em, might as well use 'em. Sometimes rolling your own is worth the time and effort. This sounds like one of those times in your use case. Since the Vewlix (to my knowledge) can't accept unmodified JAMMA video, I'm stuck on the route I'm on. Thanks for shedding some light on the subject, I appreciate it. 
J
jassin000
Allow me to fix/adjust your language slightly...
A VLX stock can't accept anything but VGA/DVI (and in a few cases/models HDMI) thats 31khz and 45khz respectfully (a few models will also accept 480i however, which IS 15khz but never common 240p).
A OSSC shouldn't accept unmodified JAMMA level video as its power is too high and WILL lead to damage of the OSSC over time (aka knock it down to SCART with a Jassifier first).
My recommend VLX owners JAMMA rig...
- JAMMA extender
- Jammafier
- Jassifier
- (HQ) 8pin mini din 2 SCART cable
- OSSC
Last edited by a moderator:
Yeah, different applications and scenarios for everyone. No situations are unique. If I had just one JVS cab, I'd grab a JAMMAfier. But I have 3 JVS cabs. So economically, it doesn't make sense to spend an amount that is just about the same as a whole new cab. I read in the JAMMAfier thread some were having issues with certain PCB's. Isolated. No biggie. Also I know JAMMAfier was designed to get that lag down to the lowest possible amount. I recommend JAMMAfier all the time for people.Yea just get a Jammafier for your JVS cab...But also get/build a Jassifier if you need SCART video levels (OSSC or other SCART based device).
The lag is so low (polling so high) its beyond human perception, not as low/nonexistent as real copper tho you'll never know or feel the difference in game play.
No incompatibility, its just not possible as all its doing is providing power and adapting/encoding JAMMA controls...
That being said because the video is unprocessed you might have issues displaying/using that, but of course this isn't the Jammafier's fault/problem.
Oh I guess for games with alternative/non-JAMMA (ie rotary/trackball) control that would be a problem, but duh (they would be a problem for any pure JAMMA supergun).
For me, where I am now beyond the n00b level, tend to be cheap, I have no problem putting in the sweat to fab a loom. Plus, I like to tinker. Ok, now let's get off this tangent and back on the OP. Frank's JAMMA adapter makes things simple for me.
J
jassin000
No debating you'll get the highest quality possible with this method, just like the JAMMA gods intended.
Hi @Frank_fjs,
So here is another use I found for the JAMMA Adapter: US JAMMA wiring to Japanese JAMMA wiring
I'm helping a buddy get his US Capcom Big Blue cab going. But he wants to play NAOMI games (MvC2/CvS2) off a NetDimm. This requires a PSU upgrade and a Capcom I/O. But the Capcom I/O does not send enough amps to power the NAOMI and NetDimm together without modification. Plus, my buddy doesn't want to pay for a Capcom I/O and new PSU. And we don't want to mess with the OG wiring inside a Capcom Big Blue cab. Welp, I have a bunch of spare Sega I/O's and a spare Negatron handy. Will use the Negatron to knock down +5vdc down to +3.3vdc to power the NAOMI and NetDimm. Now we made a harness for the US JAMMA PSU to the NAOMI using the Negatron and it works! But the problem remains, US JAMMA harnesses all have SW1-3 on the edge connector. Positions 25 & 26/c & d where buttons 4 & 5 would be are empty without pins in edge connector and it is impossible to get exact pins for those edge connectors. Japanese wiring standards have SW1-5 on the edge connector.
In comes the JAMMA adapter to the rescue! We'll just add in the JAMMA adapter. Run wires for buttons 4 & 5 from the tap points on the JAMMA adapter up to the buttons. For button 6, we'll just run that over from the Sega I/O. We took this a step further and made a kick harness that works for CPS1, CPS2, CPS3, and NAOMI all in one finely crafty solution. Boom! Here it is............
You're a life saver sir. Thanks again!
So here is another use I found for the JAMMA Adapter: US JAMMA wiring to Japanese JAMMA wiring
I'm helping a buddy get his US Capcom Big Blue cab going. But he wants to play NAOMI games (MvC2/CvS2) off a NetDimm. This requires a PSU upgrade and a Capcom I/O. But the Capcom I/O does not send enough amps to power the NAOMI and NetDimm together without modification. Plus, my buddy doesn't want to pay for a Capcom I/O and new PSU. And we don't want to mess with the OG wiring inside a Capcom Big Blue cab. Welp, I have a bunch of spare Sega I/O's and a spare Negatron handy. Will use the Negatron to knock down +5vdc down to +3.3vdc to power the NAOMI and NetDimm. Now we made a harness for the US JAMMA PSU to the NAOMI using the Negatron and it works! But the problem remains, US JAMMA harnesses all have SW1-3 on the edge connector. Positions 25 & 26/c & d where buttons 4 & 5 would be are empty without pins in edge connector and it is impossible to get exact pins for those edge connectors. Japanese wiring standards have SW1-5 on the edge connector.
In comes the JAMMA adapter to the rescue! We'll just add in the JAMMA adapter. Run wires for buttons 4 & 5 from the tap points on the JAMMA adapter up to the buttons. For button 6, we'll just run that over from the Sega I/O. We took this a step further and made a kick harness that works for CPS1, CPS2, CPS3, and NAOMI all in one finely crafty solution. Boom! Here it is............
You're a life saver sir. Thanks again!
Hi @Frank_fjs,
today I played a bit around with easyEDA. Since I like to make some adapters I tried my best to modify yours to my needs (adding holes for a volt meter). Here it is:
As you can see I also used feedback provided by @acblunden2 to improve it:
For course im happy to share the easyEDA and Gerber files when I'm finished. If someone needs them to verify my work I'll PM them and I'll upload them when finished. I hope everyone understand that I don't want to publish unfinished PCBs.
Thanks in advance for every feedback
today I played a bit around with easyEDA. Since I like to make some adapters I tried my best to modify yours to my needs (adding holes for a volt meter). Here it is:
As you can see I also used feedback provided by @acblunden2 to improve it:
Since this is the first time I have done something with PCBs and easyEDA I'm not sure if everything is fine and if it will work? Feedback is highly welcome!
For course im happy to share the easyEDA and Gerber files when I'm finished. If someone needs them to verify my work I'll PM them and I'll upload them when finished. I hope everyone understand that I don't want to publish unfinished PCBs.
Thanks in advance for every feedback
Thank you very much for verification!
Here are my files, feel free to use them for yourself
Please keep in mind that I'm not responsible for any harm this adapter does to you or your hardware. You can use my design at your own risk!
This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License.
Here are my files, feel free to use them for yourself
Please keep in mind that I'm not responsible for any harm this adapter does to you or your hardware. You can use my design at your own risk!
This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License.
Last edited:
Oh one more question @Frank_fjs: are the pads far enough away form each other so no electricity can "jump" form one pad to the other?
I've been fiddling with Easy EDA a lot lately too, pivoting off of Frank's work. Getting better with it (I think). Working on this right now:
Just want my test bench to be uncluttered. The one I've used for so long has just been a stripped out harness from a cab. I put a 3P3T switch for all 3 voltages. A hole for calibrating the meter. A DPDT switch for onboard audio to output to an external speaker or to attenuate the signal for the onboard speaker. Test points for a probe. Extra +5v and +12v connections. Ability to use external controls. Most importantly, momentary switches for signal inputs.
Just want my test bench to be uncluttered. The one I've used for so long has just been a stripped out harness from a cab. I put a 3P3T switch for all 3 voltages. A hole for calibrating the meter. A DPDT switch for onboard audio to output to an external speaker or to attenuate the signal for the onboard speaker. Test points for a probe. Extra +5v and +12v connections. Ability to use external controls. Most importantly, momentary switches for signal inputs.
