PAL N64 with DENC-NUS encoder and VDC-NUS replacement chip: size differs?!

Started by keropi, October 15, 2009, 09:07:27 PM

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keropi

October 15, 2009, 09:07:27 PM Last Edit: October 15, 2009, 09:37:04 PM by keropi
Hiya!!!

I am in the process of replacing the video encoders , but as you can see in the pics the actual chips are of different size... will it work if I replace the DENC-NUS? are the chips pin-compatible?








THANKS for any info!!!!


PS. the mobo revision is NUS- CPU (P) - 01 , will it need an RGB amplifier in the cable too?  ???

Link83

#1
October 15, 2009, 10:43:30 PM Last Edit: October 15, 2009, 10:46:53 PM by Link83
No i'm afraid the chips are not pin compatible  :(
Pinout for the VDC-NUS chip is here:-
http://gamesx.com/wiki/doku.php?id=av:n64rgb-ntsc
Pinout for the DENC-NUS chip is at the bottom of this page:-
http://members.optusnet.com.au/eviltim/n64rgb/n64rgb.html
(Both pinouts thanks to Viletim)

Yes you would also require an RGB amp, and if you are removing the DENC-NUS chip you will also lose Composite and S-Video output  :-\

You might want to try and 'piggyback' the current DENC-NUS chip and 'rewire' the VDC-NUS to match? No idea if that would work though!  ???

keropi

#2
October 15, 2009, 10:50:28 PM
Thanks!!!

I do not care about loosing vhs/svhs at all, I have another n64 if i want those...  I will use the info and rewire to the VDC-NUS standards  ;D
Will the video amp seen here sufice?  http://www.mmmonkey.co.uk/console/nintendo/ntsc-n64-rbg-booster1.htm

I am not building it my self, I re-direct all info to my technician  ::)

keropi

#3
October 15, 2009, 11:20:07 PM
OK, those are the schematics:



obviously D0->D6 are easy to find, as well as Csync , and GND points. What about VCC?  and on the left side of the VDC-NUS I connect only GND, VCC and CSYNC pins to the mobo?

damn this turned out a more difficult task than what I was told....  :(

Link83

#4
October 15, 2009, 11:57:28 PM Last Edit: October 16, 2009, 12:16:10 AM by Link83
Its been a while since I looked into this now, but I remember that some of the "?" points are actually VREF, IREF and BFP/BP - these will also all need to be connected.  I'm afraid you will have to work out which ones are which by looking at the surrounding circuitry and components (I might have a look myself sometime but I dont have time at the moment)

VCC/+3.3V is the same if I recall correctly (But please double check the voltages)

That amp would probably work, but its been discussed before and decided to be a "poor design", to quote fromViletim in this thread:-
http://nfggames.com/forum2/index.php?topic=3380.0
Quote from: viletimVoltage gain of this amplifier is something like 0.95. The Vpp would be unchanged, there would be an additional DC offset added. The exact value of this offset would depend on both the average brightness of the picture, and gain of the individual transistor used. Makes it very difficult to predict.

Basically, the idea is to reduce the impedance of the circuit to as low as possible then stick it into a TV. Then the 75 ohm load of the TV harly makes any difference to the amplitude.

This circuit relies on tolerances which vary too much...it's a poor design.
I have tried Waltazars amp myself and had quite good results on a CRT, but have also heard that it has problems on LCD's/Plasmas.

I would recommend using Viletims amp which I have already linked to in the Wiki.

Dont forget if your planning to use an RGB Scart connection you will need the Composite Video signal from the DENC-NUS chip (Or a buffered C-Sync signal - not directly from the VDC-NUS chip) in order to get a stable RGB image.

....If anyone told you this would be easy they were very wrong!  :-\

If I were you I would probably start looking for an "NUS-001(FRA)" French N64 console which plays PAL games and already has the VDC-NUS chip inside, aswell as an video encoder that outputs amplified RGB so only requires minor modding (In comparison to this planned mod)

keropi

#5
October 16, 2009, 12:37:49 AM
I see....  :-\

then due to the new developments, I am abandoning this project....  THANKS Link83 for all your info, I really appreciate it! I will follow your advice and get a FR rgb modded n64 that I see in eBay...

Link83

#6
October 16, 2009, 01:06:18 AM
Quote from: keropi on October 16, 2009, 12:37:49 AM
I see....  :-\

then due to the new developments, I am abandoning this project....  THANKS Link83 for all your info, I really appreciate it! I will follow your advice and get a FR rgb modded n64 that I see in eBay...

No problem, glad I could help :) Sorry your project would be so difficult to impliment, its a nice idea though.

If it helps there is some more info in this thread about the "NUS-001(FRA)" French N64 model:-
http://nfggames.com/forum2/index.php?topic=3083.0
If you buy one make sure it says "NUS-001(FRA)" on the bottom sticker and not "NUS-001(EUR)"

Good luck  ;D

Fab

#8
October 24, 2009, 07:24:25 AM
why are you doin this ? you want modify a pal one to get an RGB Picture ? Or do you want convert a PAL 50hz into a NTSC 60hz console... sorry for my noob question

kendrick

#9
October 24, 2009, 07:48:19 AM
Welcome to GamesX. Although many Nintendo consoles use the same video connector, they do not all produce the same signals. Have a look at the wiki page that enumerates the variants here:

http://gamesx.com/wiki/doku.php?id=av:nintendomultiav
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