hi members... i'm programming assembler and likewise c. a practical training force me to write assembler in c. the serial port names P3.1 and i can send every time 8 bit (2bit = start- and stopbit and the last 6 bit's are data). i must abide the exactly speed (baudrate) for my pc and microcontroller. in assembler is that very easy because i can use the cycle's. i have realized the delay with loops in c but the loops are very inexactly! i've got the answer to use the processortime or related. How!?!?! thank's for you sympathy yours sincerely nick