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Ravepants

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Hi All,

I recently acquired a Net City cab and wanted to put my Naomi in there, but i don't think it has the original CRT?
As far as my research tells me the Net city should have a Tri sync 15/24/31 chasis, but mine does not appear to do 31khz, only 15/24 , as they are the only 2 frequencies listed on the pots on the board, (PCB Nanao 05A00675C2), Hitachi Tube, tube surround/mount claims Nanao MS9-29SU

It came wired for JAMMA (this was working fine with a pandoras box), but I have converted it back to JVS, this is where my issues start.

The monitor has no VGA in (there appear to be no empty connectors on the board for a VGA connector either), only a 15 pin AMP UP, with R - G - B - S - G, the JAMMA loom was hard wired to this , but I cut the cables and wired in a VGA breakout, thinking that I can set the Naomi for 15Khz and it should be fine through the standard VGA cable, I wired the VGA breakout as follows:

R-G-B to R-G-B,
All RGB grounds, sync ground and ground the AMP connectors Ground.
H/Csync to Sync on the AMP connector (I am lead to believe that VGA HSync is also Csysnc?)

I figured this should work, but I get a constantly horizontal rolling picture.
I have tried removing the grounds one by one but it make no difference, and tried adjusting the H Hold on the chasis, still rolls.

is it possible I need to combine the H and V sync together? Or perhaps i need some sort of sync cleaner or separator/combiner?


one thing i did find is that is i put it all back to how it was and use the capcom I/O I have, and the naomi set to 15Khzthe picture is absolutely fine! yes this is a solution, but its messy as i have tone of boxes and cables on the cab this way!

So if anyone has any ideas and can help that would be greatly appreciated.

I can post some pics if required.

Thanks,

Rave.
 
It's a sync issue, yes. Are you sure you have the Naomi set to 15khz? I think it's DIP SW1 on the filter board. In 15khz it should output composite sync from the H Sync pin, but honestly I haven't messed it with that much. I think I've had my Naomi on 15Khz once, and that was by accident.

Anyway, you could tie both H and V sync together OR you could use the V sync input pin on the chassis. It's not wired to the 15 pin AMP UP connector, but it's there on the board.
 
Yes as nem says, the chassis has a 6 pin jst eh (sb correct me if I'm wrong) connector you can use to wire up the vsync. My MS9 works perfectly with the Naomi like this.
 
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Hi both, thanks for the input I appreciate it!

It's definitely on 15khz as that works through the capcom i/o and 31khz does not in its current jamma state.

I will try first try tying the H/V together, and failing that I'll try using the V on the 6pin on the chassis.

Thanks for the ideas and I'll post back how it goes either way! :)
 
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Yes as nem says, the chassis has a 6 pin jst eh (sb correct me if I'm wrong) connector you can use to wire up the vsync. My MS9 works perfectly with the Naomi like this.
Are you passing the Naomi video signal to the MS9 via an I/O board though?
Hi both, thanks for the input I appreciate it!

It's definitely on 15khz as that works through the capcom i/o and 31khz does not in its current jamma state.

I will try first try tying the H/V together, and failing that I'll try using the V on the 6pin on the chassis.

Thanks for the ideas and I'll post back how it goes either way! :)
So to confirm the Naomi works set to 15 khz via the Capcom I/O but not when direct via the breakout board you've fitted?

Even when set to 15 khz isn't the Naomi output voltage level still as per VGA spec so 0.7V peak to peak. You are feeding that directly into an arcade monitor designed for high impedance 4-5V peak to peak jamma video.
 
Yes as nem says, the chassis has a 6 pin jst eh (sb correct me if I'm wrong) connector you can use to wire up the vsync. My MS9 works perfectly with the Naomi like this.
Are you passing the Naomi video signal to the MS9 via an I/O board though?So to confirm the Naomi works set to 15 khz via the Capcom I/O but not when direct via the breakout board you've fitted?
I know the voltages are different, but no I'm not. I've wired the 6 pin JST EH (confirmed it actually is JST EH) to the 15 pin AMP UP and from there made a Y-splitter cable, one going to the jamma harness, and the other to a VGA breakout cable.

 
Fair enough, wasn't sure if the voltage difference was the cause of the problem
 
It will cause the screen to be a bit dimmer, but other than that it shouldn't be an issue afaik.
 
Yes as nem says, the chassis has a 6 pin jst eh (sb correct me if I'm wrong) connector you can use to wire up the vsync. My MS9 works perfectly with the Naomi like this.
Are you passing the Naomi video signal to the MS9 via an I/O board though?
Hi both, thanks for the input I appreciate it!

It's definitely on 15khz as that works through the capcom i/o and 31khz does not in its current jamma state.

I will try first try tying the H/V together, and failing that I'll try using the V on the 6pin on the chassis.

Thanks for the ideas and I'll post back how it goes either way! :)
So to confirm the Naomi works set to 15 khz via the Capcom I/O but not when direct via the breakout board you've fitted?
Even when set to 15 khz isn't the Naomi output voltage level still as per VGA spec so 0.7V peak to peak. You are feeding that directly into an arcade monitor designed for high impedance 4-5V peak to peak jamma video.
Hi Tiff_lee,

Yes, that's correct.

Via the capcom i/o the 15k picture is fine, and direct from naomi to monitor the picture rolls.
 
I no longer own a Capcom IO... But isn't this because the Capcom IO is compositing the H and V syncs together for C-sync?
Direct from the Naomi's DSUB port, even in 15khz mode I believe the system is still outputting separate syncs (hence the rolling effect)?

Oh N/M looks like its solved above by @tiff_lee because its a amplification issue (CRT needs higher amplification)?
 
I no longer own a Capcom IO... But isn't this because the Capcom IO is compositing the H and V syncs together for C-sync?
Direct from the Naomi's DSUB port, even in 15khz mode I believe the system is still outputting separate syncs (hence the rolling effect)?

Oh N/M looks like its solved above by @tiff_lee because its a amplification issue (CRT needs higher amplification)?
I think you're on the money with the sync combination as well. Oh actually I see Nem mentined it
in 15khz it should output composite sync from the H Sync pin, but honestly I haven't messed it with that much. I think I've had my Naomi on 15Khz once, and that was by accident.
but then Ravepants said he tried that already?

@Sp33dFr34k how have you got sync wired up on that cable of yours?
 
@Sp33dFr34k how have you got sync wired up on that cable of yours?
Just wired h and v sync seperately, from the JST NH to the 15 pin AMP UP (pick any free spot) to the VGA connector, pin 13 hsync, pin 14 vsync.
Yep, there's an empty spot on the JST EH connector on the chassis for V signal.

I have ordered a new EH connector and some pins, and will make up a cable like sp33d has, hopefully that will do the job, and I can leave the original AMP UP there incase I ever want to jamma it.

I probably wont get the parts until early next week but I'll up date the post with my results.

Thanks everyone for your help, I really appreciate it. :)
 
@Sp33dFr34k how have you got sync wired up on that cable of yours?
Just wired h and v sync seperately, from the JST NH to the 15 pin AMP UP (pick any free spot) to the VGA connector, pin 13 hsync, pin 14 vsync.
Yep, there's an empty spot on the JST EH connector on the chassis for V signal.
I have ordered a new EH connector and some pins, and will make up a cable like sp33d has, hopefully that will do the job, and I can leave the original AMP UP there incase I ever want to jamma it.

I probably wont get the parts until early next week but I'll up date the post with my results.

Thanks everyone for your help, I really appreciate it. :)
Good job, that's definitely the best and most versatile solution :)
 
Hi all,

Well my jst eh connectors came this morning and I wired them up, and I'm happy to say it's now working!

Amazing the difference a single V signal makes!

I've been happily netbooting most fighting games all day testing my new 6 button layout with the kick harness I got.

Thanks everyone for your help, couldn't have done it without you!

I suppose I should now make a post in the net City owners appreciation thread :D
 
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