Cartridge port sound 45 Audio from 2A03

I wish to generate sounds from the port for games. I imagine that I can send the bits by the leg 45? (famicom). It exists algun similar project?

Someone already did that here.
Source page with the repro tutorial here.
I know that there's some pirates wich use the audio too, but couldn't find a schematic.

Thanks, And that send data ? As it makes comunication serial

What kind of communication?
AFAIK you're basically mixing the audio output from the famicom with the extra generated audio.
You'll need to program your extra sound generator along with the APU.
For this you'll need to make the extra sound generator to answer to a predermined CPU address (or range of addresses) and them program it as you wish.
Hope this had helped.

I wish to generate musical notes
I wish to connect the midi to familygame without needing ROMS Generating the data in an arduino

Without 2A03 only input in RF


https://archive.org/details/familygame-midi-usb-famicom-famitracker

CHANNEL MIDI:

1 - PWM25
2 - PWM25
3 - TRIANGLE
4 - NOISE
5 - DCPM (aka. NOISE)