The UART can handle 1/12 the clock frequency, so at 12Mhz it can handle 1Mbaud. The problem is that the code to rip the bytes off the read buffer can not be written in 10 machine cycles (oh well, if you have a short message, a long pause and do not want to do anything but receive bytes, you probably can). Th bit-banging I mentioned was definitely for your second (slow) UART.

Yes, I'm Danish, have lived in Sweden and other contries, now living in North Carolina USA.

Trevlig kvall

Erik