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Volunteers Needed! - New JAMMA Kit for Vewlix (and more!) - Universal JAMMA Interface

Niko said:
Instead of a Genesis 2 style connector, why not an 8pin mini din? Doesn't the Genesis2 scart cables have components to level the video output from a Genesis?
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Because there are plenty of high quality Genesis 2 SCART, Component, and even HDMI cables (rad2x) readily available from a variety of different manufacturers. For mini din 8 you basically have to get custom cables made and you don't have access to cool stuff like the aforementioned Rad2x cables.

The Genesis 2 cable has 75R series resistors and AC coupling capacitors in the cable, but there's really not a clear disadvantage to this so I'm not sure why people always bring it up as a con for the Genesis 2 connector
 
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Arthrimus said:
Niko said:
Instead of a Genesis 2 style connector, why not an 8pin mini din? Doesn't the Genesis2 scart cables have components to level the video output from a Genesis?
Click to expand...
Because there are plenty of high quality Genesis 2 SCART, Component, and even HDMI cables (rad2x) readily available from a variety of different manufacturers. For mini din 8 you basically have to get custom cables made and you don't have access to cool stuff like the aforementioned Rad2x cables.
The Genesis 2 cable has 75R series resistors and AC coupling capacitors in the cable, but there's really not a clear disadvantage to this so I'm not sure why people always bring it up as a con for the Genesis 2 connector
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Ok cool, I wasn't complaining just generally curious.
 
I think the secondary video out is pointless given the device's intended use case. Do a single video out over a DE-15 VGA connector and call it good. The JVS spec calls for VGA-style RGBHV over DE-15 and effectively every desirable scaler out there can take DE-15 directly or via a BNC breakout cable (with BNC/RCA adapters, as needed). The Framemeister XRGB Mini guys would need a custom cable, but that's about it. As far as I know, all JVS cab monitors are tri-sync CRT, fixed 31 khz CRT, or flat panel over VGA.

That said, however, you'll definitely want TTL vs 75R and raw vs buffered vs regenerated options for the sync lines to handle basically anything, including the infamous Taito F3 (later revisions of the HAS supergun and Tri-Sync Helper being something to emulate for their sync correction and output features). Any common monitors out there explicitly require H/V sync or will everything take C-sync?

Also, given the intended use case of this, I think the PCB is best hard mounted on standoffs with the JAMMA connection being via a JAMMA extension cable. There's just too many connectors and physical mass on this PCB to not be hard mounted. DE-15 is also more mechanically secure than mini-DIN.
 
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is there a tentative date when this may be released for purchase?

im definately interested in purchasing a kit!
 
This project was sidelined for a while but I'm working on it again. I've been using the first version of this kit to run JAMMA games in my New Net City for the past few months. In that time I've made a small list of changes I'd like to make to the design to make it a little more user friendly, I've only just now started a new revision of the board but I hope to have a second more refined version prototyped within the next few weeks. If that goes well I don't see anything stopping me from launching it after that.
 
I'd be in for one if there are screw holes for mounting to standoffs. looks a bit too heavy to be comfortable leaving it all on the JAMMA edge. I'm not sure the JVS power harness even reaches far enough to get to the pcb on my cab.

It would also be cool to see an MVS remap switch (move A to bottom left, B-D to the top row), but that seems like a pcb design nightmare lol
 
Would it be possible to combine Sega/Taito/Namco control panel connectors all on the same input bridge card? Think 3x input connectors with a single output on a bridge board.

Visually looking at the mechanical packaging of the JVS IO boards in the Vewlix (Taito K91X1097B, K91X1097C, K91X1147A, K91X1245A, K9101262B - missing any?), Lindberg (Sega 837-14572, 837-15257), and Noir (Namco NAJV2), it should be possible to make a single drop-in board for all three using the existing standoff locations. Just be careful to clear the rest of the case around the standoff locations.
 
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A new (hopefully final) prototype is in production right now. Chinese new year is slowing things down, but I hope to have them here in early march.
mvBBFlc.jpg

The main change is that I expanded the size of the PCB a bit to make room for a built in -5V regulator, and cleaned up the audio and video routing significantly. Since I had extra space on the board I decided to also add a 20 pin ATX power connector for those who may not have a JVS power supply in their cabinets. I also added a switch for button 6 on the JAMMA edge in case anyone wants to run CHAMMA style boards.
 
Niko said:
Instead of a Genesis 2 style connector, why not an 8pin mini din? Doesn't the Genesis2 scart cables have components to level the video output from a Genesis?
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That ^
JESUS FUCKING CHRIST THAT!!!

Please, please, please remove that trash 9pin mini din in favor of 8pin mini din @ proper/SCART levels.
Genesis SCART cables have components inside them, thus require a video output that isn't 100% pure SCART level.
It is WRONG to place ANY components inside cables for ANY reason EVER...
and I will gladly fight anyone who disagrees to the death with the weapons/at the location of your choosing (ie have extra coffin, don't care who go's inside).

P.S. I do appreciate the HD15 connector because when using the Taito F3 PCB this is the best way to connect it (using the SCART port requires modification of the OSSC).
 
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Niko said:
Ok cool, I wasn't complaining just generally curious.
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No its NOT OK, I'm totally complaining! X(
Genesis 2 SCART cables are trash!

This design is almost perfect, why ruin it?
Why pretend something isn't a problem when it clearly IS and can be proven as such?
If your intention is to use a SCART based device like the OSSC you want SCART levels at output, not skewed and dependent on some cable (with components of its own) to alter/provide them for you.
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Let us not forget (now or EVER) the lesion of the Nintendo Gamecube...
By placing the DAC inside the component cable (and not the console itself) when the cables were no longer produced prices spiked to astronomical (200$+) levels.
We didn't have any solution for this until the DAC was reversed engineered and reproduced.

Using less words... The DAC should have ALWAYS been inside the console, because proper levels at output fucking matter.
Nintendo did it to save production costs, it wasn't with the consumers best interest in mind... Never could be with a design like that, the system is incomplete.
You want to follow in these footsteps missteps?
 
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jassin000 said:
That ^
JESUS FUCKING CHRIST THAT!!!

Please, please, please remove that trash 9pin mini din in favor of 8pin mini din @ proper/SCART levels.
Genesis SCART cables have components inside them, thus require a video output that isn't 100% pure SCART level.
It is WRONG to place ANY components inside cables for ANY reason EVER... and I will gladly fight anyone who disagrees to the death with the weapons/at the location of your choosing.

P.S. I do appreciate the HD15 connector because when using the Taito F3 PCB this is the best way to connect it (using the SCART port requires modification of the OSSC).
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Yeah, no. High quality Genesis 2 cables are readily available in many different flavors, including HD Retrovision Component cables and Mike Chi's RAD2X HDMI adapter. The same cannot be said for the 8 Pin Mini DIN. This is a project designed for convenience to get JAMMA boards up and running in non JAMMA cabinets as easily as possible. I don't know why you are obsessed with this, because there is literally no functional difference whether the capacitors and 75ohm resistors are in the cable or on the PCB, but I am not interested in reworking my design to suit your whims.
 
Arthrimus said:
but I am not interested in reworking my design to suit your whims.
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If my above examples haven't shown this isn't just some personal "whim" then we have nothing left to discuss.
Also it was first suggested by @Niko (clearly NOT me) so... Personal whim? *shakes head in disappointment*
 
jassin000 said:
If my above examples haven't shown this isn't just some personal "whim" then we have nothing left to discuss.
Also it was first suggested by @Niko (clearly NOT me) so... Personal whim? *shakes head in disappointment*
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Jassin, the only arguments I've ever seen you make about this are purely personal, and have never been backed with any actual data. You have an ideological issue with how console SCART cables were designed, and your argument starts and ends with "I DON'T LIKE IT, THEREFORE BAD". That's totally fine that you don't like it, but it's not exactly a compelling argument.

The one example you did just provide is a completely insane comparison. If you think that the Genesis 2 cable is remotely comparable to the Gamecube Component cable, then you are totally out of your mind. The Genesis 2 cable has 3 220uf electrolytic capacitors and 3 75ohm resistors inline. That's about 25 cents worth of off the shelf components. The Gamecube had a custom designed DAC that had to be reverse engineered and reimplemented in an FPGA. Show me a real example of how the using a Genesis 2 cable reduces video performance in a way that outweighs the numerous benefits that I have already explained, then maybe we can talk. Until then I think I'll continue to design my projects the way I see best suits the end user.
 
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No biggie, perhaps we can design a bypass board like was done for the SSDS3.
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You know, containing the components of the Genesis 2 SCART cable with a proper 8pin mini din port on it. ;)
I think I'll call it the "JassiFixer" or something...
 
I'm in full agreement with Jassin on this one. Capacitors have this annoying tendency to fail and leak corrosive liquid. At least if it's on the board, it's easy to clean up and fix. Inside some of these Genesis 2 SCART cables, though? I'd be better off throwing it away and buying a new one, which is admittedly wasteful as fuck, but I've tried soldering to SCART connectors. I'd rather solder to my own junk than do that again, and that was on a clean connector! These Genesis 2 cables have all sorts of shit under the SCART hood, to the point where I'm genuinely impressed that they don't generate interference.

However, you do what you think is right. I'm just making my case for what I think is an improvement. Unfortunately, in the Arcade scene, I'm not knowledgeable enough to pull off that image of John Rhys-Davies in Sliders holding up his book titled "Everything I Say is Right". So I could be entirely off-base, and that's fine.
 
Yes, that one. I can't claim to be knowledgeable enough to get away with posting that here. I'm fully able to admit being wrong in this space, because it's very likely that I am at any given point about any given subject.

I just have this pathological hatred of capacitors in places where they're harder to clean up and can take more skill than I have to cleanly replace. Sure it might not be an issue now, but after some time has passed, it could happen.
 
I don't care that Gamecube used a DAC and Genesis 2 uses caps/resistors, the lesion that we ALL should have learned from this is DONT DO THAT.
Proper = At output the signal is set, the device complete, the cables to connect it are just dumb copper that merely transport a signal (not alter it).

That way no one is bound to using any specific cabling, or getting incorrect values if they decide to hook up directly.
Many many different RGB projects use 8pin mini din now (etim's RGB NES kit maybe most famously) so purchasing these SCART cables is easy/cheap.
I dare say just as common, if not more so today than the Genesis 2 SCART cable. You'd also have the option of using this...
69m38SG.jpg


I don't understand in respect to this device why that GEN2 cable is an easier/better option?
IE the HD15 port must be pushing proper SCART values already, so you'll take that perfectly fine signal (that you would only need to add a 8pin mini din) and further skew it to get what would be proper values for the 9pin mini din when used with a Gen2 SCART cable?
God why?

Its more work adapting a common signal into two different level outputs, more components needed and locking the user to a specifically designed cable that should have been discontinued about 30 years ago.
 
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