hi,
i can give u an algorithm which i had followed in my college project....
set a timer according to the baud rate that you require. in the vector location for that timer.....do the following..
push acc and psw into stack.....get the data to be transmitted into the acc. then rotate the acc once and check whether the lsb (or msb) is one or not. depending upon that, either set or clear the acc bit and then move it into the port bit through which u want to communicate. then again load the count into the timer, pop acc and psw and return.
i guess the baud rate of 9600 gives enough time for all these operations.
let me know if this works.
regards
tushar