NeoVGA: Lagless, pixel-perfect line doubler for Neo-Geo MVS and AES

mikejmoffitt

mikejmoffitt

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I can't wait to wire it up. Unfortunately I've promised myself I won't do that until I've finished this final project I'm working on. Graduating is important!
 
bartre

bartre

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man, i'm glad this is coming together so nicely.
I'm sure it's been asked before, but what types of video will this output, just VGA?
 
mikejmoffitt

mikejmoffitt

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It'll do 480p VGA, 480p Component, 240p RGB, and 240p Component. Two switches modify the colorspace (RGB/YPbPr) and resolution (480p/240p).
 
Lemony Vengeance

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mikejmoffitt said:
It'll do 480p VGA, 480p Component, 240p RGB, and 240p Component. Two switches modify the colorspace (RGB/YPbPr) and resolution (480p/240p).
Click to expand...

are the RGB OUT lines pulled down to an acceptable video voltage for Televisions (.7v)? I mean, I shouldn't even have to ask, but just curious. This is an amazing solution :D
 
mikejmoffitt

mikejmoffitt

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They output 0.7Vp-p with respect to ground, and are 75-ohm terminated, ready to go to your PVM or XRGB or capture card or whatever. For component video, or sync-on-green, it gets a DC bias of 0.3v for the sync level. The outputs are ready to go straight to the VGA cable, and follows the application circuit of the DAC precisely, so there's no adding extra resistors and caps or other funny business.

If you wire your RGB like I do (through a VGA port with CSync on the HSYNC pin) then a single VGA port with switches for resolution and rgb/component can be used, and you don't need a redundant port. The NeoVGA in 240p mode is a better DAC than the original one, if only because it's not a cheap linear resistor DAC with 5% rated resistors...
 
GohanX

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I'm probably the only person in the world to ask this, but would it work on a CDZ?
 
mikejmoffitt

mikejmoffitt

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It ought to. I just don't have one, so I can't promise that until I've messed with one. However, all the Neo-Geo systems can mostly be broken down into there generations, and the last one (MV1C, all-in-one JAMMA, maybe CDZ?) use the NEO-GRZ ASIC and it has slightly different timings. I still support it, though, through an option jumper on the PCB.

If you want to donate a CDZ, I'd be happy to try (or borrow, but there's a chance your shit can get ruined because it's mechanical and I can only be so patient)
 
Lemony Vengeance

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mikejmoffitt said:
They output 0.7Vp-p with respect to ground, and are 75-ohm terminated, ready to go to your PVM or XRGB or capture card or whatever. For component video, or sync-on-green, it gets a DC bias of 0.3v for the sync level. The outputs are ready to go straight to the VGA cable, and follows the application circuit of the DAC precisely, so there's no adding extra resistors and caps or other funny business.

If you wire your RGB like I do (through a VGA port with CSync on the HSYNC pin) then a single VGA port with switches for resolution and rgb/component can be used, and you don't need a redundant port. The NeoVGA in 240p mode is a better DAC than the original one, if only because it's not a cheap linear resistor DAC with 5% rated resistors...
Click to expand...

I want this even more now. Thanks!
 
bartre

bartre

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Does this do anything different than the RGB going out of the system, or is the RGB out simply a bypass solution (so there's less holes, like you mentioned)
 
mikejmoffitt

mikejmoffitt

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The RGB is captured from before the original DAC, but when it's on 240p mode it's more or less a pass-through (no scaling or processing done, other than Component conversion optionally)
 
xsq

xsq

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this is some good stuff. Thanks for the additional info and all the best for your graduation.
 
-SD-

-SD-

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This is an amazing achievement, can't wait to get one installed in my AES :buttrock: It'd also help with consolizing the PGM too assuming it works with that system.
 
mikejmoffitt

mikejmoffitt

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Alright, I sent out a bunch of e-mails and private messages to everyone on my spreadsheet. It's a pretty generic one, so please don't be offended if it's relatively impersonal!
 
fenikso

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mikejmoffitt said:
Alright, I sent out a bunch of e-mails and private messages to everyone on my spreadsheet. It's a pretty generic one, so please don't be offended if it's relatively impersonal!
Click to expand...

Did I not make the cut? I posted in the other thread that I was interested, but if I'm too late, then it is what it is.
 
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