I came across this forum after looking for information on how to mod an SMS2 for A/V out capability.
My friend said he'd seen some people doing it and wanted to know if I could do the mod on his console for him.
I Googled around and found several websites showing circuits similar but not the same: Some don't use resistors, some use a capacitor on the audio line and some don't. Some use audio from one IC, some take it from another.
What all seems to be consistent however is that they use 220uF capacitors on the video lines - This seems odd as every diagram shown in the CXA1145 Datasheet shows 470uF capacitors used.
And that brings me to another question:
What is the difference between the first example circuit and the other two?
The first shows all video outputs with two 75 ohm resistors, one in series with the signal and the other going to ground.
Similarly, the audio output has a 10K ohm resistor going to ground.
Neither of the other two circuits have these resistors.
Also, in the first circuit, the composite output from pin 20 has two connections: (C) and (C') - what is the use of (C') ?
Can anyone help answer these questions?
Thanks in advance.