Set a timer up for the proper buad rate. You may need to make it high priority if you have busy interupts.

Note you can use a delay loop, or a timer with no interupts

on the interupt....

switch(tx2_state)
{
   case 0:	 // tx not in progress
	break;
   case 1:	 // send start Bit 1
	TX2_BIT = SPACE;
	tx2_state++;
	break;
   default:  // states 2,3,4,5,6,7,8,9 data bits lsb first
	TX2_BIT = (tx2_byte & 0x01)?MARK:SPACE;	// send LSB
	tx2_byte = tx2_byte >> 1;	        // shift for next Time
	tx2_state++;
	break;
   case 10:	 // send stop Bit 
	TX2_BIT = MARK;
	tx2_state++;
	break;
}

translate to asm and you are done.
enjoy