OK, I got that to work more-or-less. Proof:
The screen is slightly noisy because I had a long cable run to the TV and also assembled it on a breadboard. One slight snag, I don't have an NES controller so I can't actually move my character around. I'll order one from eBay, but what sort do I want exactly? Just a classic NES controller?
Errata:
- On the circuit 4FSC pin number is not marked (it is pin 3).
- You might mention that AD725 pins 9 and 11 are NC.
- On the Atmega328 the AUD pin number is not marked (it looks like it is pin 11).
By the way, I didn't have a 14.31818 MHz oscillator (waiting on a delivery) so I used the 17.734475 MHz one which had arrived. I tied pin 1 to Gnd rather than +5V (to indicate PAL) and it works fine.
I haven't tested the sound yet.
It's ultra cool however. I'm really impressed you managed to squeeze this sort of performance out of it. Once I get my controller I'll be able to give it a real test.