I believe I have the answer
Well, I think I figured it out. Here is the solution to using non-standard baud rates on a PC:
1) Use the TIOCGSERIAL ioctl to get the serial_struct for the
2) Set the ASYNC_SPD_CUST flag in the serial_struct "flags"
field and set the "custom_divisor" field to whatever you
3) Use the TIOCSSERIAL ioctl to write it back.