NES RGB mod

Started by Bostich, August 29, 2005, 08:22:17 AM

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Live_Steam_Mad

#200
Playchoice 10 PCB's (with RP2C03B PPU in a socket) come up on Ebay at least once every 3 or 4 weeks. Some go for about ten GBP, some for 30 GBP or so, but not much more than that. Most still have their PPU. Some have no heatsink on the PPU. Some have PPU missing. A lot are untested  and seem to come from UK sellers (nearly all UK sourced ones have Brent Leisure stickers on them it seems, whoever they were?).

Cheers,

Alistair G.

panzeroceania

ah, so I should be checking ebay.co.uk

thanks for the tip.

Jon8RFC

HVC-101 able to be modded?

I haven't seen any info other than someone selling this:
http://www.sega-16.com/forum/showthread.php?t=16290


I've left my NES sitting in San Antonio, alongside my playchoice board, for at least a couple of years.  I just don't have the time or drive to make the mod happen.  Now that I've seen 1) the HVC-101 (which I didn't know existed, I though there was just the bubble-top NES2), and 2) that it has been RGB-modded, I'd prefer that for space, top-loading, standard Nintendo AV output, and lack of needing to hack up the case itself.

Drakon, what would you charge me to do every possibly improvement you've found to give me an amazing video output?  I read your post elsewhere about the AV Famicom having a superior picture when modded, which is what lead me to shift gears on hardware desires.  Stereo mixing would be amazing as well, if you're comfortable with that.  A potentiometer for adjustment would be handy, so I can tweak to my liking.

I'm content with s-video output, if that's your forte.  My Aptus-1 is a failure compared to running s-video right out of my SNES...unless you suggest that I shell out for the Premium RGB --> component converter from the same company, and go RGB all around from NES to N64.

On a side note, what would you charge me to fix the Japanese RGB N64 I purchased?  I think it needs an amp at minimum.  It works, but it's unplayable because of the dimness.  The quality is unacceptable as well.

Live_Steam_Mad

#203
OK so I last night cut off my Composite PPU from my USA NTSC Toaster NES. Just checked the traces on the PCB and I did no damage yet. I checked the traces and solder pads with a magnifying loop (8x) (and also later on checked with the loupe that I did not bridge any connections with the desoldering of the legs that remained in the PCB that needed removing). When cutting the legs of the PPU I used the silver coloured tool which is shown in the picture attached. Not sure what this tool is actually for, it's made in Germany and probably more than 25 years old, I inherited it from my late father. It's jaws are curved upwards in the vertical axis which is very strange. Anyway it worked a treat for *almost* cutting through the legs at the top of the PPU chip. After I had used this silver tool on every leg of the PPU, I then used the Tamiya brand Modeller's Side Cutters (straight edged) as shown in the photo's that follow (Google Picassa link in next post, below) to snip completely through each leg at the top (you get a loud click as it cuts through each one, worked great).

Then I desoldered the legs which remained embedded in the PCB, by gripping the PCB by the top right corner of the component side of the board in a mini table vice (smooth jaws) and using an Antex 50W TCS series soldering iron set to medium temperature with the 1mm single eliptical faced, chamfered (angled) bit (they are interchangeable) (I prefer more powerful irons in general LOL) along with a little Deans brand Racing Solder (for RC cars) to get some heat conduction, I held the iron bit against each connection on the solder side of the board for about 8 seconds or so whilst simultaneously pulling on the leg of the chip left embedded in the board on the component side with a pair of Tamiya brand long nose pliers with smooth jaws, and pulled each PPU leg out. I only pulled at the leg whilst the leg was being heated. The smooth jaws limited the grip that I got on the leg on purpose so as not to tear a trace or bend the board or fracture anything.

I must say it was quite easy and enjoyable, except for pins 14, 15, 16, 17, 19, and 20 which were an absolute bitch to remove as they refused to come out without quite a few minutes total spent on each one pulling and twisting (without bending the board too much I hope). Of course, I only heated each connection for about 10 seconds maximum each time and tried removing it then waited for it to cool down and then repeated until each one of the difficult ones came out.

Pic's in the link in the following post of the operation and of how the board looks now.

I would like to get an RGB to component converter for use with my RGB modded NES and Infocus IN76 projector and use a component video switcher or my Sony STRDA1200ES AV amplifier to switch between the component connections, since I normally use a Component connection on my projector for my Pioneer LX60D DVD / HDD recorder. I use HDMI and analog audio for my PS3 at the moment LOL. I listen almost always on headphones to watch "TV" with.

NEStopia 1.40 has an option in options/video/palette to change from YUV to RGB so you can preview the change to using an RGB PPU in a NES emulator. Suddenly SMB becomes like the box art LOL.

BTW my video projector shows very vibrant composite colours from my NES with no interference on the picture at all. But it's got the Composite color palette and the "vertical lines have zig zags" problem that the Composite PPU generates.

Before I did this PPU removal I reconnected this my USA NTSC Toaster NES with serial number below 1 million (N0639771) to my Infocus IN76 projector via composite lead (after I had just modded it for stereo audio with a quick soldering of cables, just before my hot glue gun to arrived) and checked and I got no white borders anywhere with the standard composite PPU

Best Regards,

Alistair G.

Live_Steam_Mad

#204
More pic's ;-

https://picasaweb.google.com/LiveSteamMad/RGB_NES_mod02#

I tried to attach multiple pic's at once to this forum but it won't let me and to add them one by one is not practable. So Google Picassa it is then.

Cheers,

Alistair G.

DaddyLongLegs

Just did this mod to my NES, but the jailbars are there :(

They aren't huge, and it's not noticeable in all games, but you can definitely see it in Super Mario Bros 1 and 2.

I am assuming that since I am using a toaster NES I have to live with it? :(

Zom

Can someone tell if there are any major differences on modding a Famicom, or is it basically the same procedures?
I modded mine for compositea good while ago, but if there won't be too many complications that arise from Famicom/NES differences, I'd love to try & replace the PPU on mine.

Thanks.

Live_Steam_Mad

#207
OK I first tried to remove the solder that was left in the PPU holes in the PCB by using my Antex 50W TCS iron @ medium temp with the 1mm single eliptical face (angled face) bit and thought against using braid or a solder sucker, and then instead was trying to do it using a pin made from a cut off section from a large Safety Pin, held in a pair of pliers, with the 3mm or 6mm single eliptical (angled / chamfered) face bit, slightly tinned, held against the pin to heat it, melting the solder in the holes, but the holes kept re-sealing with solder LOL so I removed all I could and then made sure each blind hole was a little depressed in the middle, and then drilled each hole out with a Swivel Head Pin Vice and a 0.7mm drill bit. Worked great, now my precision IC socket fits the PCB perfectly it seems. Not soldered it in yet...

Quote1. Desoldered the original PPU from the NES
2. Soldered a 40-pin IC socket where the PPU used to be

You need a praecision instead a standard IC socket for a good connection.

3. Soldered wires to pins 14,15,16,and 21 (red, green, blue, and sync, respectively)

The RGB Pins should not connect from the socket to the pcb, because it is ground.
You have also ONLY lift the 3 RGB pins, not Pin 21.
Take composite sync from the yellow Video RC Socket from the HF-Modulator.
You need an amplifier for the RGB signal.

I saw in a reply to the original poster that Mooseman mentioned "Take composite sync from the yellow Video RC Socket from the HF-Modulator", does that mean that I open the RF box and solder a yellow wire to this point in my attached picture? (picture to follow in a moment)

I just ordered 7/0.2 mm red, green, blue and yellow equipment wire (PVC insulation, eyuk I hate it, silicone is way easier to solder but seems only to be available in larger sizes of wire only?).

Cheers,

Alistair G.

Live_Steam_Mad

#208
> "Take composite sync from the yellow Video RC Socket from the HF-Modulator", does that mean that I open the RF box and solder a yellow wire to this point that I labelled with a red arrow, in my attached picture below?

Also, in which case, how does it manage to produce Composite Sync from there when I have cut out the Composite PPU ????

EDIT: Oh I see, because pin 21 of the RGB PPU generates Composite Sync which then gets amplified by the circuit inside the RF box that would normally amplify Composite Video from the Composite PPU. RGB Displays need this Composite Sync in addition to the raw RGB apparently, so the RGB PPU generates it always, to suit the RGB displays.

Cheers,

Alistair G.

kschafer2598

Quote from: Drakon on September 22, 2010, 12:43:32 PM
Quote from: xenomus on September 21, 2010, 12:32:16 PM
So, I'm working on my RGB kit for the Famicom AV and I'm getting close! But all I seem to get is pictures like these:

http://imgur.com/hqxwt.jpg
http://imgur.com/hkDzg.jpg
http://imgur.com/UK3CT.jpg

It appears to be pulling sprite information from the wrong addresses, or something like that. It should be noted that I can't get the one actual Famicom game I have to load up. The only games that I can get to load are NES games thru a NES-to-Famicom converter. Sound comes through just fine. It's just the pictures are garbled. At least the colors are crisp and bold thanks to the RGB! But, yeah, this is something of an issue.

And I'm pretty sure it's not the fault of the converter, since I got NES games to play on the system with it just fine before I started the modding. The PPU I'm using is RP2C03B, which I think is compatible but I'm not 100% sure since my Japanese is rusty. (For reference: http://homepage3.nifty.com/F-LABO/ProductsList.html ; third item down.)

Any advice?

yikes, only time I had stuff like that happen was when some pins weren't connected, check your connections.  I really gotta find a way to make a low pass filter to get rid of these stupid lines...

Did you ever find a solution?

I've been trying to get this mod to work on my Famicom (non-av) with the same results - garbled sprites. Games do play and sound good, just garbled all up.

After also ripping apart my NES, I got the PlayChoice PPU installed there, and the picture looks great! No sprite issues.

I do want an RGB famicom since I prefer the looks of the japanese console and it'd be easier to use the famicom disk system on it.

Please help!

marqs

Seems like some address/data lines are short-circuited or unconnected. I'd also check the cartridge connector pins. My famicom has similar issues if I push the cartridge full way down, but if I pull it a bit up from the bottom then it's fixed. I have RP2C03B inside the famicom so it shouldn't be a compatibility issue.

kschafer2598

Quote from: marqs on May 30, 2011, 05:42:54 AM
Seems like some address/data lines are short-circuited or unconnected. I'd also check the cartridge connector pins. My famicom has similar issues if I push the cartridge full way down, but if I pull it a bit up from the bottom then it's fixed. I have RP2C03B inside the famicom so it shouldn't be a compatibility issue.

Thanks for the info, I'll give it a shot. Weird thing is that with the stock fami PPU it works fine - no glitches. I was thinking that maybe I screwed up  a trace or crossed something somewhere but since the standard PPU works I'm not sure what could be wrong.


Salamander

#212
Followed this mod using the THS7314 but mostly Moosmann techniques (thanks much for putting all this info out there) and it looks amazing.  While I was at it I got to wondering if it was possible to take the RGBS lines off the RP2C03B and, using an AD725, getting Chroma/Luma/Composite.  I built the circuit following Ben Heck's diagram here...

http://www.engadget.com/2006/11/28/how-to-consolize-an-arcade-game/

Anyone else tried something similar to this?  

The video signal I get out of the AD725 is basically a green screen with a faint image of what should be present but it's scrambled.

Salamander

Instead of sending the CSync from the RP2C03B into the AD725 and sending it straight out the back to the television it produces this.  Sort of Gameboy-ish but still not where I want to be  ???

Salamander

Success!!!  AD725 apparently is fussy about the sync signals it receives so if you try this go with a sync cleaner.   S-video shot of Castlevania which turns out quite nice from this encoder in my opinion.  The Composite signal however is dot crawl paradise so be warned!  I'm going to try the luma trap once the inductors show up but don't have high hopes for that end of this project.

One additional issue I notice while running S-Video...a faint herringbone type pattern that runs 2 o'clock-8 o'clock.  I'd assume this is sync related as well but what residual issue could there possibly be after sending this through a JROK?

Live_Steam_Mad

#215
Oh Boy what a job that was. PPU socket now soldered in (I used my 50W Antex TCS iron on medium temperature and used the 1mm single eliptical face (angled face) bit, using Deans Racing Solder with ProFlux), RGB PPU inserted, and I can hear music coming from my speaker so looks like my early USA NES isn't dead  :D And the first of my RGB PPU's worked!!  :) Happy Days!!

The PPU I am using is RP2C03B with purple / brown body and Gold legs, marked 9F3 27, removed from my 1986 PlayChoice 10 PCB, PCH1-04-CPU, serial no. C-013507. EDIT: I have two RP2C03B's marked with this same 9F3 27 batch number, the other one had the mashed legs. The one I used here has the straight legs.

Now just got to tidy things up and figure out what the heck I'm going to connect the RGB to.

I found that although I filed down the 3 legs on my precision style IC socket for pins 14, 15, 16 and put 1 piece of PVC electric tape (should have used cloth tape like Markus but didn't realise that until later on doah!) on the PCB covering those 3 holes, I had soldered the 3 RGB wires to the bottom of where the pins used to be (before I filed them off), and the wires and solder had then to be filed down with a very fine file (you get them cheap from hobby shops) yet again as much as I could get away with, and even then only about 1mm of the full length pins or less came through on the other side protruding from the PCB above it's surface on the no-components side of the PCB.

Also had to smear the bits of solder with the iron around every hole on the component side of the PCB to flatten them down as best I could and then redrill (from the non-component side) some holes where it filled them back in by doing this. Still there was well enough of each pin sticking though on the non-component side to solder to, but I did find myself checking each pin on this side with a cheapo 8x  magnifying loupe and refreshing the solder joints several times over for quite a few pins before I was happy with every joint, and I checked for bridged joints also. Fortunately the PPU that I used had already had the heatsink removed so that was one less stage that I had to do.  Seems to work.

Can't tell at the moment whether I am going to get a picture out of this yet LOL.

Cheers,

Alistair G.

Salamander

#216
Got the last of the video issues resolved and as it turns out the herringbone/crosshatch was being caused by the xtal.  Replaced that and it's a herringbone free image so here's a little more eye candy to keep those working on this motivated (I hope).  The infamous CV2 title screen, not so bad really, but it's for sure got the most noticeable jailbars of any game I have on hand to test.  

Most games do seem to run glitchfree but the two problem titles I own are Megaman 2 and Kirby's Adventure though the issues are minor.  There is currently a 120pf cap soldered in between pin 24 and gnd.  Anybody tried further experimentation with values here to see if it can be totally resolved?

Live_Steam_Mad

#217
Quote from: Salamander on July 26, 2011, 01:00:40 AM
the herringbone/crosshatch was being caused by the xtal.  Replaced that and it's a herringbone free image

You replaced the NES's 21.47727MHz Crystal with another crystal of the exact same frequency ? Which exact brand and item code of crystal did you use? Does it matter which way round you solder it in?

BTW I have a SNES with this herringbone pattern problem on the screen but only on the S-Video connection, composite seems to be almost entirely free of it, when viewed on my Infocus IN76 projector.  The herringbone pattern is only visible on my In76 projector on S-Video from the SNES and never on my Sony 29" Trinitron TV when using S-Video from the same console. I have suspected the cheap (probably unshielded) S-Video custom SNES adapter cable in the past but could it be the SNES's crystal? In which case could I solder into the SNES the exact same replacement crystal that you soldered into your NES to remove the herringbone / crosshatch pattern on your NES?

Cheers,

Alistair G.

Salamander

@Live_Steam_Mad:  It's actually a separate but related issue with the s-video encoder.  It requires a 4FSC xtal to generate the chroma/luma/composite and while experimenting to try and resolve the issue I discovered it was the problem.  As for the herringbone issue on the SNES, are you getting an audible hum in the video?  I ran into a similar issue using the 'cheap' multi-out -> SCART off eBay and wound up just building my own using high quality shielded cable with a drain wire.  The unofficial cables on eBay are cheaply made 28 or 30 gauge using a common ground for everything with no shielding.

Live_Steam_Mad

#219
Quote from: Moosmann on September 23, 2005, 10:36:54 PM
RGB Amplifier:


Sync and Audio:


Final (black wire is 5V, brown wire is ground):


Bye Markus

Can I ask please Markus, in your picture labelled "Sync and Audio" above (which seems to be a picture of the RF modulator of the NES), it looks like your red wire has shielding around it and runs inside the left side of the double wire (figure 8 cross section) black cable, and connects to the audio ((red) left hand RCA socket in the picture i.e. amplified (by the RF box circuitry) mono sound (left and right audio channels mixed into one audio channel)) and the blue wire also looks like it has it's own individual shield and runs inside the right hand side of the double wire black cable, and connects to the ((yellow) right hand RCA socket in the picture, i.e. amplified composite sync from the RP2C03B PPU (as opposed to amplified composite PAL or NTSC video from RP2C02/RP2C07)) and that you have used one of the shields (the one from surrounding the red cable) to connect to the metal plate (is that ground?) that the 2 RCA audio and video sockets are attached to. And you seem to have put black PVC electrical insulation tape around this shield wire that connects to ground? Is that right?

Where does the other end of the red wire go to? I am guessing to your NES's stereo modification to mix with the 2 mono channels to get nice stereo mix effect like I and many others have done?

Where does the other end of the blue wire go to? I am assuming that it provides Composite sync on that 8 pin DIN that you installed on the back of the NES for any RGB to Component converter or RGB SCART connector or similar?

Where does the other end of the Ground cable on the left of the red wire go to? Does it connect to your 8 pin DIN connector to provide video ground for an RGB SCART cable for example?

In your photo labelled "Final", is that black wire I can see coming off your amplifier PCB going to the NES PCB to the last pin on the far right of the cartridge connector to get 5V off the cartridge connector to power the amplifier with? So your RGB amplifier is getting power from the NES?    EDIT: Yes this must be true since I later connected this end pin of the NES edge (cart) connector to my Moosmann amplifier and the amp works so must be 5V.

In which case why is there another black wire going from near that wire on the amplifier PCB to the 8 pin DIN connector? What is that for? (I am assuming it's +5V to go through a 75 Ohm resistor and then into SCART pin 16 ("RGB selection voltage", between 1 and 3 V is to switch the TV to RGB input mode automatically).

Also can you post the amplifier picture / schematic that you used that had the broken link above?

Cheers,

Alistair G.

Salamander

Visit this website: http://playoffline.wordpress.com/mod/nesrgb/

I prefer using a THS7314 as an amp for the RGB over using a mishmash of transistors and resistors. 

It's very simple to build as it's a single 8 pin IC (small too!). 

Go to this website (translate): http://baku.homeunix.net/RGB/RGB_FC/RGB_FC.html  and scroll down to RGB Buffer Amplifier for a diagram and parts list.

Moosmann

I already use THS7314 OPV since the last 3 Mods, but without the 100nF Capacitor between 5V and GND (causes very small errors in the amplified signals).

Greetings Markus

RGB32E

Quote from: Moosmann on July 29, 2011, 08:31:24 PM
I already use THS7314 OPV since the last 3 Mods, but without the 100nF Capacitor between 5V and GND (causes very small errors in the amplified signals).

Greetings Markus

Do you use a cap between 5V and GND for your THS7314 circuit?  If so, what value?  Do you use the existing circuitry in the NES for CSYNC, and tap from the composite video output connector?

Moosmann

#223
I don`t use a capacitor between 5V and GND Pins on the THS OPV. I take composite Sync from the Multi-Out (AV-Famicom) or like my old US NES Mods (it is the same).



BTW: Modifications with a C1 PPU, you have chance C5 (220uF) to a smaller capacitor in order to place the C1 PPU with heatsinks

Greetings Markus

Live_Steam_Mad

#224
Responding to something someone mentioned earlier about the PlayChoice PCB's, I tested each of my 5 PlayChoice 10's (serial numbers C010996, C013507, C013450, C011325, C008239) (I think they are all single monitor boards) and I found that PPU pin 17 is always connected to PPU pin 20 with no resistance, and that PPU pin 20 is always connected to ground with no resistance, this all being tested by not having any PPU's in any of the PlayChoice 10 PCB sockets.

I tested the 4 off RP2C03B PPU's that I have left (not for sale) and pin 17 is always connected to pin 20 inside the chip with between 38 to 43 Ohms resistance so there is a connection internally inside the chip between the two pins but there are components between the two pins.

Tested with DT830B cheapo multimeter (+/- 0.8 per cent rated accuracy on Ohms allegedly, not bad for 3 quid. But when I tested it, it is always 0.6 Ohms higher than it should be (zero resistance displays as 0.6 Ohms, and a 2.2 Ohm resistor with 1 per cent tolerance displayed as 2.8 Ohms, but at least the voltage readout on a 12V 7Ah battery agrees with my hobby charger's LCD readout within 0.01V, but the only adjustment pot internally inside the DT830B is for voltage, there is no adjustment for resistance).

Cheers,

Alistair G.

Salamander

Quote from: Moosmann on July 30, 2011, 04:30:06 AMModifications with a C1 PPU

C1 NES TV also used an RGB PPU?  If so, that's another commercial release so I really don't understand the folks who see the minor palette issues as such a big deal.

About the grounds...lifting 17 has never made a difference for me on this mod.  The interference is really not that bad unless it's displaying certain colors (light blues or the blue-green color of CV2 title).  For the most part you will either never notice it or the improved overall clarity more than makes up for it.

Live_Steam_Mad

#226
I just wired up my RGB NES's green PPU pin to pin 11 of my SCART input on an opened up SNES cable as a quick test. I tested and get continuity between the RP2C03B's "green leg" i.e. 6th pin from the right on the chip, i.e. PPU pin 16, and the SCART pin 11. And  I get SMB1 music through my TV but no picture at all (TV doesn't sync). It's a Sony portable 14" TV (UK model). How do I test if it's working (what is the minimum needed) ? Do I need a ground hooked up? If so, from where to where?

Also I tested and there is continuity between the metal ground going all the way around the NES PCB and pin 17 and pin 20 of the PPU. However PPU pins 14,15,16 are definitely not connected to ground, so looks like I lifted those pins properly.

I just need to see that one of the 3 colors works (it's OK for it to be very dark for now as long as I can see that it's working).

Do I need to put +1 to +3 V e.g. from an AA cell on SCART pin 16 and -ve to pin 18? As this selects RGB instead of Composite...

http://en.wikipedia.org/wiki/SCART

Do I need anything on pin 21?

Just had a thought, this TV is UK so might not be capable of sync'ing to 525/60 and 3.58MHz NTSC color subcarrier or RGB - will go and test the TV with something else to verify.

EDIT: Nope, TV in front room (29" Sony CRT) accepts 525 lines @ 60 fields/sec and 3.58MHz NTSC and RGB and still I get only sound and no picture.

I notice that my Infocus IN76 projector uses "Sync on Green" on Component, where there are 3 RCA jacks colored red, green and blue and if you only insert the green you get a picture but if you put in the others on their own you don't get a picture. Not that I am willing to risk connection of anything to my projector until I get a picture on either of my 2 TV's first... but is my SCART problem anything to do with Composite Sync needed to be connected to the SCART green pin (11) as well as the green RGB wire from the PPU?

EDIT : I just read that "RGB SCART gets the Sync signal from Composite video" (here ;- http://www.mmmonkey.co.uk/console/nintendo/rgbntsc.htm#link83 ) , I suppose that's why there's no picture, it's because there is no Composite Sync wired up to Composite Video IN on my SCART yet...

Help!

Alistair G.

Live_Steam_Mad

#227
Yeay...just connected test wire from Composite Sync coming out of the  RF modulator section (which is connected to the yellow RCA jack's hole) to pin 20 on SCART (Composite Video In) and instead of a jet black screen I'm getting a very dark grey screen with interference on most of the upper section of the screen and what looks like a very faint picture of the wall on Super Mario Bros 1 along the bottom of the screen. No color yet.

Is this all the picture that you get from a non-amplified RGB output  ??? ? There's next to no picture at all...but very faint indeed. Brightening the picture doesn't help.

I think I'll connect up the RGB Green ground (pin 9) of SCART to NES PCB ground next to see if I get a proper dark green picture.

EDIT: Nope, connecting SCART pin 9 to ground on NES PCB just wipes out my picture back to very dark grey with NOTHING visible.

HELP

Alistair G.

Salamander

Output even non-amplified should be present just too dark.  SCART takes sync from composite video on pin 20 so send csync from the RF box there instead and it should work.

A site to visit for some additional help with console SCART: http://members.optusnet.com.au/eviltim/gamescart/gamescart.htm

Live_Steam_Mad

#229
Quote from: Salamander on August 04, 2011, 12:21:07 AM
send csync from the RF box there instead and it should work.

I already did that (the solder point that I showed in my picture above on the RF box's PCB, same as yellow RCA hole, going to SCART pin 20) and that's the thing that got me a picture at all, without it I had no picture whatsoever. Now I have a picture but it's VERY faint. This being on the 14" Sony portable with FD (flat) Trinitron screen.

So far I have PPU green hooked up to SCART pin 11, and SCART Green Ground ready to be hooked up to NES PCB (but when I do my picture vanishes completely but the line stucture is still there so Sync is working. Also have Composite Sync from RF box (yellow RCA inner) connected to SCART pin 20.  The connections are direct, no resistors or capacitors.

Next I'm going to try making the amplifier circuit for the green color channel as I just got the components. I suspect that the PPU chip's output is weak (current-wise) and that the voltage may be being dragged down too low (SCART has 75 Ohms resistance in the TV circuit PCB ?) and the amplifier would I imagine provide a power transistor that can deliver more current and a voltage that doesn't drop under load so hugely brighter picture? I'll soon find out.

I was just depressed and irritated to see how the unamplified picture wasn't just dark it was almost not there at all!

Cheers,

Alistair G.


Live_Steam_Mad

#230
Quote from: Salamander on August 04, 2011, 12:21:07 AM
A site to visit for some additional help with console SCART: http://members.optusnet.com.au/eviltim/gamescart/gamescart.htm

Ahh now I know why Markus Brandel (alias Moosmann here) is using an 8 pin DIN connector to go from RGB NES to TV, it would appear he's using a Megadrive / Genesis to SCART cable as shown further down that web page you mentioned http://members.optusnet.com.au/eviltim/gamescart/gamescart.htm#megamstr. Markus's webpage is in German so I am using http://translate.google.co.uk/translate?js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&sl=auto&tl=en&u=http%3A%2F%2Fplayoffline.wordpress.com%2Fmod%2Fnesrgb%2F to translate, but he doesn't mention that you use a Genesis / Megadrive cable to connect RGB NES to TV. He must have forgotten to include that information??

One thing is odd though, the pinout that Markus gives matches the Megadrive / Genesis to SCART cable EXCEPT where Markus has pin 5 of the DIN as audio and the above page says that DIN pin 5 should be Green. Also, Markus has pin 7 of DIN as green, whereas the above web page says that pin 7 should have no connection!

Why is this? Who is incorrect?

Cheers,

Alistair G.

Salamander

It's because his DIN pinout is custom and could be wired any way you want.  What you see at that link is what is output at those specific pins without modification from the original console.

Live_Steam_Mad

Is there a web page with a diagram that shows you how to connect an RGB NES to SCART ?

ARG

Salamander

You can wire up the DIN side any way you like so long as the SCART end is correct (it can only be done one way).  Copying the NTSC SNES pinout should work fine though the caps are basically optional.

Live_Steam_Mad

Quote from: davidleeroth on December 12, 2007, 11:28:26 PM
Ok, changed the CPU and the crystal to NTSC's so now this bad boy is working! The composite picture on the NES had a huge issue with dot crawl and it's all gone now. The improvement is clear in pics but you can really appreciate when there's movement i.e. the first scene of Life Force, which in composite looked ridiculous. I'm very impressed.

The RP2C03 palette does make some games look a bit different, like some Konami games look like they're on MSX but that's to be expected. Games with cartoony colors and graphics like Mega Man seem to come out the best. All in all, the trade-off is well worth it.

Moosmann, I get vertical stripes in some games as well, but they only appear with my RGB monitor. My Sony TV doesn't have even a trace. The stripes are grey on black areas like intro screen in Probotector II.

In your PAL NES that you RGB modded and put NTSC CPU in, which revision PAL NES  was this? Do you have a photo of the PCB ? And a serial number? Would be interesting to know since I also have a PAL NES but if it gives the jail bars when RGB modded then I'll stick with my NTSC Revision 4 NES with serial number N0639771 on the underside of the NES, and of year 1986 on the PCB.

Cheers,

ARG

Live_Steam_Mad

Here is the appearance of my screen (Sony 14" CRT) with just PPU Green and Composite Sync and no grounds wired up ;-

ARG

Live_Steam_Mad

#236
OK I built the Moosmann amplifier, but only 1 amp out of 3 yet, from Markus's web page of http://translate.google.co.uk/translate?hl=en&sl=de&u=http://playoffline.wordpress.com/mod/nesrgb/&ei=FJoxToK0CY608QPpt5mhDg&sa=X&oi=translate&ct=result&resnum=1&ved=0CB4Q7gEwAA&prev=/search%3Fq%3Dhttp://playoffline.wordpress.com/mod/nesrgb/%26hl%3Den%26client%3Dfirefox-a%26hs%3D0BV%26rls%3Dorg.mozilla:en-GB:official%26prmd%3Divns, I used a CTBC337-25 transistor (seller told me was Philips brand), and a CTBC557B that the other seller told me was Fairchild Semiconductor brand. Transistor pinouts were both the same as on Markus's web page (it seems). I used 1 per cent tolerance resistors, metal film type, and an electrolytic capacitor (i.e. polarised) in the amp, as prescribed by Markus on that page.

I wired up the PPU Green to the amp. IN, and Green OUT of amp. directly to pin 11 of SCART, no other cap's or anything. I left the Green Ground (pin 9 of SCART) dangling on a flying lead.

Now when I feed the NES into the Sony KV-14LT1U 14" FD Trinitron CRT 4:3 TV I get a picture (as before) since I have Composite Sync (yellow RCA inner pin from RF box on NES) wired direct to pin 20 of SCART, no other components in the path, and I have Green connected, but the picture is a hell of a lot brighter than the almost non existant picture that I was getting before.. I get music from the NES. I can see SMB 1 playing nicely on the screen BUT it's a little faint for my liking (maybe because the other 2 color components will make it brighter later on) and it's got wavy lines (but less than before) on the screen, and it's in Black and White, NOT green, which I thought was odd. Also if I connect pin 9 of SCART (Green Ground) to the NES PCB the picture is very dark (and still black and white).
The wavy lines dissappear when I ground pin 9 (green ground) to the NES PCB.

 Not sure if this TV can even handle RGB LOL. There is no button on the remote for switching the TV to RGB either. I suppose that means I will need 1 to 3 V on pin 16 of SCART, and I assume that would also mean I have to ground pin 18 of SCART to the NES since pin 18 is the ground for pin 16?

However when I fed the same NES into the Sony 29" CRT TV (KV-29K5U) which can take RGB and 525 lines / 60 fields/sec, 3.58MHz NTSC, it WON'T sync (except now and again very briefly and then I can see that it looks OK brightness) and everything is distorted, unless I connect pin 9 of SCART (Green Ground) to the NES PCB and then it sync's but the picture then goes INCREDIBLY dark. Also both "pictures" are in black and white, same as my 14" TV when I know that this larger TV can do RGB or NTSC color at 3.58 or 4.43MHz.

Next I will try making 2 more amp's on my perf. board and try running a ground for Composite Sync onto the NES PCB, and will also try grounding the 3 colors of R, G and B.

Below is what my TV picture now looks like on my 14" Sony with my amplified Green. No grounds wired. Only 5V and ground from NES PCB to the amp. of course. The Moosmann amp. obviously works and the signal is way more than before. Ignore the colored red and blue curved fringes lines, they are aliasing from camera chip / CRT screen.

I just want to know why my picture is black and white on both TV's LOL.

EDIT: I just found out that if I disconnect the mono audio from the RCA input on the front of the TV the picture doesn't sync on the 14" TV unless I ground either Green or Composite sync and then I get a picture.  I remember that on my brother's very similar 14" Sony upstairs (older model, not flat Triniton) the  RCA video / audio sockets cannot be used at the same time as the SCART as they seem to be connected together internally inside the TV! And of course the audio ground from the mono audio is connected to the NES RF unit so that's where the return path for ground is coming from. Hence why when I connect the mono audio from the NES into the front of the TV it suddenly gets sync, as it's using the audio ground to ground the Composite Sync!

If I have both Composite Sync's Ground and Green's Ground connected together to the NES PCB I get a picture on the 14" TV, but the picture is quite dark compared to not grounding those. If I do the same on the 29" TV I get no picture at all. But if I connect just Green Ground to NES PCB and not CSync ground I get a picture on the 29" but it's incredibly dark (almost not there at all). This is annoying, what the hell do I do about this?

HELP!

Cheers,

Alistair G.

Live_Steam_Mad

#237
1 more pic of what I'm getting out of SMB 1 at the moment on the 14" TV with just PPU Green connected (and NO grounds connected in this picture except of course for audio ground)... a little depressing  :-[. On the upside, at least the Composite artefacts seem to be gone, vertical edges are now straight finally! ;-

Cheers,

ARG

Moosmann

#238
You have to connect +5V to Scart Pin 8 and via 75 Ohm Resistor to Pin 16. If its doesnt`t work, take the other Scartsocket from your TV.

http://i16.photobucket.com/albums/b14/moosmann/electronic/md1rgb.png

The 8 Din Pinout from my NES Mod is the same Pinout like you modified a NEC PC Engine DUO/R/RX. My RGB Modified PC-Engines are backward compatible with the normal AV Cable.

The 8 Din Connectors are available in "O" and "U" Layout. The Sega Megadrive use the "U" Layout for the Pins. Unfortunately, an nice and stable metall housing plug is not available for "U" Plugs,  so that i prefer the " O" Plugs.

Because the NES have only audio mono, i solder a bridge between 2 pins,  so that i can use the same "Stereo" PC-Engine RGB Cable for the NES.

Greeetings Markus

Live_Steam_Mad

#239
Markus, you are right once again!

I just connected my chipped PlayStation 1 to the 14" TV and used the RGB SCART cable that my Uncle gave me and put in Tomb Raider 1 (NTSC USA) and as soon as I switched on the PSX the TV instantly switched over to RGB mode and I saw a beautiful color picture (I have never seen it do this before on this TV) and showing the 3 green dots on the OSD (On Screen Display) which indicates RGB mode in use on the TV, just like I see when I use RGB mode on the large Sony TV in the front room. So this PSX is giving pin 16 at least 1V to activate RGB mode and this 14" TV can do RGB.

So yes I need to give pin 16 at least 1V on my NES's SCART cable in order to switch this 14" TV to RGB mode when used with the NES, as I never saw the 3 green dots on the OSD at any time so far with the NES on this TV. Will do, and report back.

Thanks!

Alistair G.