Hi,
I've got a French PAL NES and I'm trying to hook it up a computer (I've got no real TV) . I've been told French NES only output RGB. Would there be a quite simple hack to get composite out of the NES ? The PPU is a 2C07.
Thanks for your help !
Alex
The French NES uses a custom AV/RF/AC module which converts the composite video from the NES board to RGB output. It has nothing to do with the PPU.
If you want, you could buy a French NES (if you can find one) and desolder the modules then swap them around.
French NES also uses a custom video cable only available in the same places it was. Unless you want to do some creative rewiring, its advisable to get one of those as well.
If you're in PAL territory I'm guessing you'd have SCART. IIRC thats what the FR NES video cable outputs to.
Hi
Thanks for your answer
To be more precise my two NES are actually French, with PAL RGB on SCART and no composite. I'm in France, so that's my only easy option.
The problem is I own no TV set, so I cannot use SCART. What I wanted to do was to use a computer as display. The computer I planned to use is a Silicon Graphics Indy with built-in video-in but it has only composite and S-video (like most computers anyway).
So, I did a bit of reverse-engineering yesterday. I soldered an RCA female plug on the pin connecting the motherboard to the AV module. This is the pin closest to the corner of the module.
So now, I've got composite out of my NES. Victory !
The only thing is that I find the colors a bit strange. Dimmed, like. Maybe the signal level is a bit low. Maybe I'm missing a bit of electronics.
Has someone got the schematics of the module of a composite version for me to compare and maybe complete the circuitry ?
I could find the schematics of the motherboard, but not of the AV/RF/AC module.
Thanks !
alex wrote:
To be more precise my two NES are actually French, with PAL RGB on SCART and no composite. I'm in France, so that's my only easy option.
The problem is I own no TV set, so I cannot use SCART. What I wanted to do was to use a computer as display.
Why not connect the SCART directly to your computer's monitor? Or does your monitor not go down to arcade scan rates like 15.6 Hz?
There's no scart on a computer monitor, but I guess that's not what you mean ?
You mean connecting the RGB pins from the SCART to the input of the computer ? If the the signals are compatible between SCART and VGA it would be a good idea.
Actually, I didnt consider this, because the computer I want to use (the Indy) is hooked up to a LCD screen that uses a proprietary input (not VGA or other usual stuff) where RGB values are transmitted on a digital bus over 24 wires (or is it 48 ?). This is 15y old equipement. At that time there was no standard among LCD screens. The video card is also proprietary and works only with this screen.
alex wrote:
You mean connecting the RGB pins from the SCART to the input of the computer ? If the the signals are compatible between SCART and VGA it would be a good idea.
That's what I was thinking about. SCART RGB is a "standard resolution" signal with a 15.6 kHz horizontal frequency, the same used by old CGA monitors, Apple IIGS RGB monitors, and standard resolution arcade monitors. The lowest resolution VGA modes has a minimum scan rate roughly twice this. Some monitors, especially those made by Wells Gardner, can handle 15.6 Hz, but a lot of VGA monitors can't.
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Actually, I didnt consider this, because the computer I want to use (the Indy) is hooked up to a LCD screen that uses a proprietary input (not VGA or other usual stuff) where RGB values are transmitted on a digital bus over 24 wires (or is it 48 ?).
So that's what they had before DVI, right?
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This is 15y old equipement. At that time there was no standard among LCD screens.
I didn't know, as modern cheap computer LCD panels use VGA.
Excuse my ignorance, but I thought the FR NES only took a composite signal and ran it through a scart connector, so while the picture appears via a scart conncetor, it is actually just a crappy composite signal. Is there no simple adapter?
-Rob
tepples wrote:
The lowest resolution VGA modes has a minimum scan rate roughly twice this. Some monitors, especially those made by Wells Gardner, can handle 15.6 Hz, but a lot of VGA monitors can't.
True. My main CRT display is given for 30-96Hz, and I guess the others are no better. And I don't feel like getting an old CGA or EGA out of the cupboard just for this.
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So that's what they had before DVI, right?
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I didn't know, as modern cheap computer LCD panels use VGA.
AFAIK it is the only standalone (ie not in a laptop computer) LCD of the early 90's. So I guess there was no standard at all. I seem to remember around USD 10000 at the time. Screen and board alone. The computer was the same.
rbudrick wrote:
Excuse my ignorance, but I thought the FR NES only took a composite signal and ran it through a scart connector, so while the picture appears via a scart conncetor, it is actually just a crappy composite signal. Is there no simple adapter?
I'm no expert. From what I read, the French NES is the only one with native RGB output. I'm pretty sure now that the SCART pin for composite is not wired at all.
In the small AV/RF/AC box there is a Sony V7021 chip whose purpose is to convert the composite output by the PPU to RGB for the SCART.
I think it is an interesting piece for those who want RGB and only have composite.
Alex, I'm almost certain that there was a thread here once that a poster examined a FR NES and saw that it was not RGB at all...just composite running through an SCART connector. I do not believe the FR NES is RGB at all. Can't find the thread, though.
-Rob
rbudrick wrote:
Alex, I'm almost certain that there was a thread here once that a poster examined a FR NES and saw that it was not RGB at all...just composite running through an SCART connector. I do not believe the FR NES is RGB at all. Can't find the thread, though.
-Rob
The french NES is indeed RGB out on the scart connector. This is because france wanted to be different from everyone else and use SECAM instead of PAL. It's like PAL just with an extra refreshing zing. Sooo, the french NES has a regular ol' PAL gut with a PAL PPU, which sends its composite to the modulator, where a PAL to RGB decoder lives. This decodes the signal into RGB which is fed to the TV.
You can recover the PAL video but as someone already found out, it's lower level than what a TV likes and is dark as a result. You need to boost it a tad to use it.
kevtris wrote:
The french NES is indeed RGB out on the scart connector. This is because france wanted to be different from everyone else and use SECAM instead of PAL.
System Essentially Contrary to American Method
Systeme Elegante Contre les Americains
Quote:
It's like PAL just with an extra refreshing zing.
SECAM has the same scan frequency as PAL but uses FM instead of QAM for the color subcarrier, which hides things like dot crawl, hue distortion, and a few other artifacts seen in NTSC. In addition to the color encoding difference, which shows up in baseband composite video, broadcast PAL and SECAM also differ on a few aspects in the RF domain (frequencies, x vs. 1.0-x modulation, etc).
kevtris wrote:
rbudrick wrote:
Alex, I'm almost certain that there was a thread here once that a poster examined a FR NES and saw that it was not RGB at all...just composite running through an SCART connector. I do not believe the FR NES is RGB at all. Can't find the thread, though.
-Rob
The french NES is indeed RGB out on the scart connector. This is because france wanted to be different from everyone else and use SECAM instead of PAL. It's like PAL just with an extra refreshing zing. Sooo, the french NES has a regular ol' PAL gut with a PAL PPU, which sends its composite to the modulator, where a PAL to RGB decoder lives. This decodes the signal into RGB which is fed to the TV.
You can recover the PAL video but as someone already found out, it's lower level than what a TV likes and is dark as a result. You need to boost it a tad to use it.
Hmm, ok, I understand it converts the signal to RGB, but is the signal better than composite, or does it look like true RGB?
-Rob
It probably uses a PAL color decoder board, such that the RGB signal faithfully reproduces PAL artifacts. I think the level-following circuit that I have suggested before that tries to infer the hue and brightness of each pixel would have been too expensive to implement.
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It probably uses a PAL color decoder board, such that the RGB signal faithfully reproduces PAL artifacts. I think the level-following circuit that I have suggested before that tries to infer the hue and brightness of each pixel would have been too expensive to implement.
Ok, good. I guess I wasn't totally crazy after all, then.
Are PPUs PAL/NTSC dependant? Or rather, is it possible to use a Duck Hunt or Tennis Vs. PPU to make the FR NES true RGB via SCART?
-Rob
I don't know if my German NES is the same as the units in France, and I don't understand much to that signal thing, but my NES only have one jack output, which seems to multiplex audio and video in some way. A Nintendo-made adaptater should be placed between the output and the TV in order to get a true PAL video signal and a separate audio channel in order to connect it to a TV.
The PPU is a PAL one, and probably directly output a PAL video signal directly, that is only amplified (and multiplexed with audio ?) by the output circuitery.
rbudrick wrote:
Are PPUs PAL/NTSC dependant?
Yes. These exist:
- NES PPU with NTSC timing that outputs an NTSC signal (used in Famicom and North American NES)
- NES PPU with NTSC timing that outputs an NTSC signal, run through an NTSC to PAL/M decoder board (used in Brazil NES)
- NES PPU with PAL timing that outputs a PAL signal (used in some European NES)
- NES PPU with PAL timing that outputs a PAL signal, run through a PAL to RGB decoder board (used in other European NES)
- NES PPU with NTSC timing that outputs an RGB signal (used in Vs. and PlayChoice)
Nintendo never made these to my knowledge:
- NES PPU with PAL timing that outputs an RGB signal
- NES PPU that outputs an S-video signal
There's also the official and unofficial NTSC Famicom systems in Hong Kong which output a PAL RF signal. One of Bung's first products is a transcoder board for the FC. I'm not sure if the official HK Famicom has NTSC or PAL output though.
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NES PPU that outputs an S-video signal
I've read that if one had access to the pixel clock, one could do a 100% perfect Y/C separation and thus artifact-free S-Video output. Any truth to this, and if yes, how feasible?
NewRisingSun wrote:
Quote:
NES PPU that outputs an S-video signal
I've read that if one had access to the pixel clock, one could do a 100% perfect Y/C separation and thus artifact-free S-Video output. Any truth to this, and if yes, how feasible?
If you have M2, you can post-process the NTSC PPU's output to recover a perfect artifact-free stream of palette IDs, which can be further processed into a conforming RGB, component, or S-video signal. But to do a proper analysis of a pixel's high level, low level, and phase, you'd probably need to have an ADC that samples both at high and low states of the master clock, which comes out to 12 times the color subcarrier frequency. That'd be 43 MHz on NTSC or even higher on PAL, rawther expen$ive.
EDIT: fixed when the ADC needs to sample
Just a quick correction, M2 is not the clock you want. M2 is the CPU memory access clock not the 21Mhz clock.
43MHz ADC is obviously way too fast for the PICs that I know of. Are there dsPICs/AVR/FPGA that would be able to do it?
How about a delta ADC and FPGA?
Don't delta ADCs have slope overload?
And you can regenerate the master clock from M2 with a PLL, right?
Yes, it's clearly not as good as a delta sigma DAC :) I guess you really need a discrete flash ADC + FPGA. The good thing though is that FPGA have enough memory for LUTs.
Why can't you just use M1 @ 21Mhz instead of M2? Skew?
Since there are so few PPU output voltages (10 or so?), could you just use several comparators, one for each level?
tepples wrote:
- NES PPU that outputs an S-video signal
doesn't
Sharp Famicom Titler do that?
I had forgotten about that one. There are past posts like
this that discuss the Titler;
search for them. Specifically,
kyuusaku seems to think that the Titler has an RGB PPU:
- NES PPU with NTSC timing that outputs an RGB signal, run through an RGB to NTSC S-video encoder board (used in Famicom Titler)
In fact my PAL NES and SNES output a RF signal (It's written RF out on the jack).
There is also spearate audio and video outputs on the side of the NES, I don't remember seeing anything equivalent on the SNES and I've never used them on the NES either. I pass the RF singal trough an adaptater called NESP-003 which has a inpuf forom the RF, another input that I use on my VHS recorder, and the output to the TV.
I don't know if the french NES is identical. All 3 of my NES are mostly identical (at least when it comes to I/O) and they say "NESE-001" and "FRG" on the back. All text on these are in german.
Hi,
Mine has no jacks. The box has this 2x5 pin custom Nintendo connector out (labeled "RGB out") and the cable that goes there ends up in a SCART connector.
I am 95% sure there is no composite out the SCART. There is composite in the console before the small RF box containing that sony V7021 chip.
This chip converts composite to RGB. I've soldered my RCA just before this chip.
Inside the box, the RGB pins of the PPU are linked to the ground, and maybe there isnt anything going out them. I have no scope to tell precisely.
I think the signal out of the SCART is PAL : Usually, when I send SECAM to my computer I get a grey picture. Here, I get colors. Ugly colors, but colors anyway. What I don't know is whether this ugliness is :
- due to the fact that I'm getting the signal out of the NES too early
- normal (I havent seen a NES for 20 years before these two)
- due to the signal being in fact SECAM but accepted on the PAL input of my computer and not grey as an exception.
France's official standard is SECAM, but almost all TV sets have been PAL/SECAM for ages, so it would not surprise me if the NES was only putting out PAL. The doc coming with the NES doesn't help.
If I ever come across a real TV set, not a computer, I'll see what it gives with PAL and with SECAM.
alex wrote:
Hi,
Mine has no jacks. The box has this 2x5 pin custom Nintendo connector out (labeled "RGB out") and the cable that goes there ends up in a SCART connector.
The french NES uses a PAL PPU (like the UK NES). It then goes to an RGB decoder to recover RGB which is then sent out to the scart. The PPU does not output RGB or anything other than composite PAL. This composite does not leave the NES except after conversion to RGB.
Tapping the PAL composite signal before the conversion will work, but levels will probably be low (i.e. not proper voltages) so while it may work, the video will be dark possibly.
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Mine has no jacks. The box has this 2x5 pin custom Nintendo connector out (labeled "RGB out") and the cable that goes there ends up in a SCART connector.
I'm pretty sure my SNES has this connector (however I don't use it), but my NES lack it, and have direct A/V jacks instead. I only use RF anyway.
Hi
I finally got it thanks to this thread (beware, it's in French) :
http://www.metagames-eu.com/forums/les-tutoriaux-oldies/nes-creation-dune-sortie-audio-stereo-et-dune-sortie-video-composite-91069.html
Quick summary for those who don't speak French (then you're unlikely to have a French NES, but well...) :
The PAL composite is on the pin closest to the corner of the RF/AV little metal box soldered to the MB. As expected. That's where we pick the signal up.
As also expected, the level is quite low and the colors are too bright. To solve this, you have to replace R2 by a 47ohm (original is 150ohm), and add another 47ohm serially between the RF module pin and your newly added RCA jack. That's all.
The thread on Metagames is doing this a bit more complex. The guy adds a switch and keeps R2 (so either you go through R2=150ohm either you go through the new 47ohm). This is to keep the possibility to go back to RGB when needed. He also adds a wire to send the composite not only to a RCA, but also to the Nintendo connector so that you get composite out the SCART (and RGB. And you use the switch. Got it ?).
I only added the two 47ohm and the RCA jack, and there I go (and another RCA for sound - nothing fancy : just picked it up the next pin on the same connector). When I need RGB, I have a second unmodified NES.
Even if you don't read French you can follow the link, you'll find pictures.
I've gotta go now. Mario's waiting for me.
Donc c'est définitvement vrai, il n'y a que les NES françaises avec la sortie RGB/Péritel (tu me diras si c'est écrit FRA au dos de la tienne, sur mes 3 NES c'est écrit FRG, comme sur les cartouches ou FRA signifie france tandis que FRG signifie une autre région (allemagne ?)).
Ceci probablement parce que la France est le seul pays ou les TV officielles sont en SCEAM et non en PAL ? Donc sortir du composite PAL sur une télévision SCEAM ne fonctionne probablement pas, et c'est pourquoi Nintendo a décidé de sortir une NES différente en France ? Il semblerait que sur la NES Nintendo ait changé d'avis et fait qu'une console universel avec tous les connecteurs, dont un petit connecteur allongé qui, en france, doit sérvir à racorder le péritel à travers un cable ?
En tout cas moi je passe le RF à traver un petit adaptateur gris (qui contient quelques condensateurs et quelques bobines si je me souviens bien) et qui permer de le racrocher à l'antenne et à la télé (il y a donc 2 entrées et une sortie).
Les deux sont FRA. Il n'y a pas de SECAM qui sort, uniquement du PAL. Le module RF/AV et sa puce Sony font la conversion composite -> RGB mais laissent l'image en PAL.
Le connecteur allongé sert bien à brancher la péritel.
Par contre pas de RF (antenne) du tout sur les miennes. Le signal n'existe pas.
I could really go for some freedom fries right about now.
-Rob