N64 RGB (Gah, different models) +other N64 stuff

segasonicfan · Post by **segasonicfan** » Wed Oct 20, 2004 9:29 pm

Well, I have 3 N64's: a 1996, a 98 and a 99. The 98 and 99 models work but I broke the 96 model a while back. Recently, to my disappointment, I discovered that the 96 model is the only model I have which is RGB-mod compatible...because the other two have differenct video ICs! The pinout is completely different and the chip is that NUS crap. I read some earlier threads on this, but it doesn't look like a mod is available. Using my multimeter and doing some work today I figured out most of the pinout for the outputs on the chip (on the right side, pins 17 to 32). Here's what I got:

32-? +3.07v
31-? +1.21v
30-? +1.21v
29-Y (luma)
28-Ground
27-Comp Video
26-Ground
25-C (Chroma)
24-Ground
23- +VCC in (5v)
22-Ground
21-Ground
20-Audio left
19-Ground
18-? +1.67v (and it just ends at a capacitor...)
17-Audio right

I want to test the '?' lines for RGB but I don't know how to get Sync out of this thing...is it mixed with the Composite Video Signal? There's a diagram on GameSX for the LM811 Circuit which can be used to separate the Sync info...is that what I should do? Once I get sync I can start testing the outputs...hopefully RGB is there.

On a side note, I also have news about the N64 power supply. I wired up a portable DVD player battery (7.4v 6amp li-poly cells!) and got a full 2 hours life running the system and a un-modded PSOne Screen! The cells are very thin (something like 2 cm) and can easily fit in the bottom of the N64. The trick to it I found was NOT using a 3v DC-DC converter but taking the 3v right off one of the battery cells! That way it can get close to the 6amps and the 7.4v output can still be used for the screen and the 12v line (but I'm planning on using a 5v DC-DC converter to save more power). Anybody thought of this? It works extremely well and I highly recommend it if you have the batteries to perform it (and its nice not having to bother with those 12 AA's).

Okay, that's all folks...let me know if anyone has any ideas on the RGB stuff.

-Segasonicfan

Post by **gannon** » Thu Oct 21, 2004 4:58 am

Have you tried looking for the rgb mod that taps capacitors instead of the actuall points on the chip? I'm not sure if that one works for the newer n64's either though.

segasonicfan · Post by **segasonicfan** » Thu Oct 21, 2004 3:29 pm

yes, the capacitors on the RGB mod (1996 board) are not present on the newer boards. The resistors the RGB lines run through arent there either (111 ohms). Therefore I have no choice but to follow and test the pins directly off the chip.