The rare rc2c05-04 ppu...

*note* The pallette of the rc2c05-04 ppu is 100% identical to the pallette of the rp2c03b / rc2c03b. Here's some proof.









If anything looks different in these pictures it's because the lighting changed slightly. The colours on these ppus are 100% identical.

There happens to be a few nes style rgb chips that were manufactured. The most common chip is the rp2c03b found on playchoice 10 arcade mainboards. However there's some more obscure / rare chips out there. Some of them came with altered pallettes making them unusable in a regular nes system. Pallette data is hard coded into the chip so there's no way to adjust it without the use of something insane like a fpga. I heard that the rc2c03b chips can drop into the nes and work without any modification just like the rp2c03b. However rc2c03b chips are a royal pain to find. And the rc2c03b does the same thing as the rp2c03b. There is one other chip that out there, and that would be the rc2c05-04. This chip doesn't work if you drop it into a nes or famicom. The pallette of this chip isn't the problem, in the case of this chip nintendo switched two address lines on purpose to make this chip only compatible with a pcb that's wired for it. A while ago I stumbled across a japanese page by baku where he built a circuit that allows you to use the rc2c05-04 on a regular nes / famicom. However baku didn't originally post the schematic for his circuit. Recently baku posted on gamesx and posted his schematic here:



Ignore IC1 that's just a rgb amp I have many of those sitting around. I went to my local electronics store and found ic2 and ic3 so it looks like I'm in business to build this circuit. One of my early clients (onyxdomain) managed to get his hands on one of these extremely rare rc2c05-04 chips and me's mailing it to me and paying me to build the circuit and install this chip into a home system. I'm fairly excited to see the results as this is the first non rp2c03b chip I've ever worked with. I'll probably be the second person in the world to get one of these chips working on a home system (the first being baku) so basically little is known about this chip. I have no idea what type of pallette this chip has but I do know that the pallette is famicom compatible so it'll be interesting to see if this chip shares the same pallette of the rp2c03b or if the pallette is closer to the composite ppu pallette.

*edit*

I've built the circuit and it works fine. I'm waiting on an AV famicom AV upgrade kit so I can install this thing into a system.

I got this chip running in a nes 2 I was commissioned to build (commissioned by the dude who bought this obscure rgb chip and mailed it to me)





Everything works perfectly it's safe to say this project is 100% done. Again huge thanks to bakutendo for coming up with this circuit.

Was a bit depressed to learn it didn't have the composite color palette like some people speculated, but it's all good because I actually enjoy the RGB color palette.

OnyxDomain wrote:

Was a bit depressed to learn it didn't have the composite color palette like some people speculated, but it's all good because I actually enjoy the RGB color palette.

I now have two of these chips here. Guess they're not as rare as I thought?

Hi, what is the game you have got running there on your RC2C05-04 PPU ? Has it got a name that I can Google and find? Or can you post some pictures of some western games being played on it?

Does it have the 2 short blue vertical lines glitch on USA Super Mario Bros 2?

Cheers,

Alistair G.

There is no glitching at all in mario 2. You've never heard of contra?

If you have a ppu that glitches that's probably because something is blown in your ppu chip. Here's a video I made showing a clients glitching rp2c03b chip vs one that's working normally.



His chip only seems to glitch on contra most other games looked fine. The chip is no different than the fully working one it probably just is partly faulty. This is actually the first glitching I've ever experienced with any chip. The only regular glitching you get with these chips is in the bubble man stage of megaman 2 when you're underwater occasionally it draws the wrong tile for a split second in random places.

Drakon wrote:

There is no glitching at all in mario 2. You've never heard of contra?

If you have a ppu that glitches that's probably because something is blown in your ppu chip. Here's a video I made showing a clients glitching rp2c03b chip vs one that's working normally.

His chip only seems to glitch on contra most other games looked fine. The chip is no different than the fully working one it probably just is partly faulty. This is actually the first glitching I've ever experienced with any chip. The only regular glitching you get with these chips is in the bubble man stage of megaman 2 when you're underwater occasionally it draws the wrong tile for a split second in random places.

I tested on my RGB modded USA NTSC Toaster NES Revision 4 (NES-CPU-04) and all 5 off RP2C03B's from my five PlayChoice 10 boards have the same glitch in USA NTSC Super Mario Bros 2. Markus (Moosmann) mentioned that the glitch is normal for the RP2C03B, and a 68pF cap doesn't solve the problem.

Here's what I am seeing ;-

http://nfggames.com/forum2/index.php?topic=1592.msg30764#msg30764

http://nfggames.com/forum2/index.php?action=dlattach;topic=1592.0;attach=1400

https://picasaweb.google.com/lh/photo/dXBc6VURwtV01UWUJgVjSJsL1cJbDsUCEqprHCeUogU?feat=directlink

https://picasaweb.google.com/lh/photo/Xe2ALNii8PfLz9AY71mDC5sL1cJbDsUCEqprHCeUogU?feat=directlink

3 of my PPU's have a different batch number to each other. 3 had heatskinks, 2 didn't.

All worked perfectly in USA NTSC Super Mario Bros 1. No glitch on the right hand last column of pixels. Only in SMB2 does this happen. Maybe related to my NES revision. The glitch in SMB2 happened both before and after I installed the 68pF cap from pin 24 to pin 20 (Moosmann's mod). Salamander on NFG Games also gets this same glitch in SMB2.

I wonder if it's something to do with my actual cart?! Since different games seem to give different glitches (but I don't know whether different batches of the same cart could give a different glitch).

Markus said that although the glitch in SMB2 is "normal for the RP2C03B", the RP2C03C from the C1 TV and the Titler RC2C05-99 PPU don't have the glitch in SMB2. Neither does the actual PlayChoice 10 when playing PC10 SMB2.

Yes I know about Contra but I don't play shoot 'em ups hardly at all LOL I just tried the Gryzor ROM (Japanese version of Contra it seems) in NEStopia like you are running on that NES 2 above, and I see that in Composite palette mode the lower part of the Konami symbol is brown, and the skin tone on the guy on the right is pink, whereas in RGB the Konami same part of the symbol is now red and the skin tone is now yellow, same as in your picture above. It's a real bummer that the RC2C05-04 turns out to have the RGB palette!

Cheers,

Alistair G.

Drakon wrote:

You've never heard of contra?

Where he's from they probably call it Probotector.

I thought id mention that the Rc2c05-03 also works exactly the same as the rc2c05-04.

I sent one to drakon a while back to test out, and it worked.