And now for something else: NES RGB mod

[ckong]

Because I'm a bit stuck regarding my attempts repairing the monitors of Black Widow and Tempest, I thought it would be a nice change to do something console related today, in casu RGB-modding my NES. So I did, took me whole afternoon.

However, without the help of Etiènne I couldn't have done it. Most difficult part namely is the first step, remove the original PPU from the NES mobo and solder it on the RGB board. My (de-)soldering skills are not good enough for that job, but fortunately Etiènne offered to do this, it took him almost a year    and with this nice result (the board is in the yellow rectangle). Thank you, Etiènne.  




What remained to do for me was soldering a lot of wires on the board and install the S-video connector, the RGB-connector, sound jack, moddong the NES case and test it of course. And yes, succes!! (I could use a hobby related success this week).

Here are some pics of the NES RGB mod work of today:














Here a few pictures of some NES games (shown on a Sony PVM monitor), 240p RGB, bloody sharp and Scanlines!!!!  









Tomorrow back to Black Widow and Tempest, I guess.  

[Etienne MacGyver]

cool !  i am happy it works !

Video of the desoldering process will be uploaded soon  

By the way, your solderpoints look perfect also 

[joeks]

Great work Erik and Etienne!
The image it produces looks ace!

Thinking about doing this mod for some time now.
But probably it's a too much (and expensive) for the amount of playtime my NES gets.

And bought a very nice Famicom recently, which I still have to AV-mod before I can use it
Just love the small size and design of the thing. Not to mention the colorful and smaller game-cartridges.

[level42]

Holy crap is that entire extra board ONLY for RGB ?? That's pretty crazy lot of hardware needed for just that !?!?! Or does it also give you each and every game ever released for the system ?

But.........it looks fantastic !

[ckong]

The board gives RGB,  S-video,  some sound options and 3 selectable color palette options (on the fly) .  And if you eliminate the RGB output,  by a switch,  then the original composite video and audio data is deverted to the original video connector,  so you can hook it up to a composite video receiver,  like a TV.  Not that you would want to do that,  RGB is far more superior,  hence the mod. And it works with the Everdrive multi game solution. 

[Etienne MacGyver]

Video of the desoldering process will be uploaded soon  

[ckong]

Very nice video and very original way to remove the PPU. I will link to the video in the respective SHMUP thread: http://shmups.system11.org/viewtopic.php?f=6&t=47617&p=1118269#p1118269

One hint: I had trouble reading the scrolling text because of its fast pace. Could be me of course. 

[Etienne MacGyver]

hehehe, yeah me too, it was a quick and dirty editting job 

Glad you liked it

[leonk]

technical background on NESRGB:

- the NES PPU chip only outputs composite video (Playchoice-10 is the only PPU that has RGB out, but the color pallet is not the same as NES, some games have slightly different colors.  e.g. brown where it's supposed to be more red).
- the FPGA on NESRGB sits between CPU and PPU and intercepts writes to PPU
- it forces PPU to output most of the digital data (color vectors) on the PPU's EXP pins (these pins are normally connected to ground!)
- only missing data is if color belongs to foreground, or background.  To force that data out of PPU, the FPGA will force picture to black and white palettes. Then analyze output from composite video which will tell it if the color was foreground or background!

Now NESRGB has all the info it requires (color and sync information) in pure RGB.  It can then output the RGB, or convert it internally to S-Video or composite which is much cleaner than the old NES PCB which has a lot of added noise.

It was a huge breakthrough that occurred on NESDEV back in 2013.  It was Tim W. who made the NESRGB the commercial success it has become.  If this wasn't for this work, a lot more PC10 systems would be killed for its RGB PPU.

[level42]

That explains the extensive hardware, thanks !