Yes that technique looks like what I was describing at first (using the timer interrupt to handle the buffer).

I think after I actually wrote up the ISR, I can get all my processing done right in the interrupt. It's just a bunch of switch and if statements so the actual thread of execution stays quite short.

As for doing it in mainline, it can't work in my situation, I need to do the byte processing in some interrupt.

Thanks
John K.