JP1 Remotes

Yep. Works fine. Here's how to connect:
https://www.hifi-remote.com/forums/viewtopic.php?p=127948#p127948
Thanks for the link. That is helpful! That looks solely as UART/serial mode... which might be ok (not sure yet) but I suspect the need will be more in a bit-bang mode. Thoughts?

Before I jump ...

Ok, so I may be up for the challenge to write a SAM8 tool mode recovery program... BUT, I will need a little info first: I am not 100% sure on the pinout and how to set the hardware up beforehand. I have a ATT Uverse S30 remote I can tinker with. It has the 4 pin (odd) connector on it and I am ...

I *think* this is what you are looking for...
https://static.arantius.com/misc/S3%20E ... amming.pdf

It describes Tool Mode programming for the S3 / SAM8 protocol.

Let me know if this is helpful or I am off base.