I am working with the AT89S53 and try to get Terminal messages. i looked at the "Hello World" example and did exectly as they did in the example. i still not get the "printf()" commands to the serial port as i have to. pleas advice me by send me a short example. the "Hello World" example monitor configuration: /*------------------------------------------------ The main C function. Program execution starts here after stack initialization. ------------------------------------------------*/ void main (void) { /*------------------------------------------------ Setup the serial port for 1200 baud at 16MHz. ------------------------------------------------*/ #ifndef MONITOR51 SCON = 0x50; /* SCON: mode 1, 8-bit UART, enable rcvr */ TMOD |= 0x20; /* TMOD: timer 1, mode 2, 8-bit reload */ TH1 = 221; /* TH1: reload value for 1200 baud @ 16MHz */ TR1 = 1; /* TR1: timer 1 run */ TI = 1; /* TI: set TI to send first char of UART */ #endif /*------------------------------------------------ Note that an embedded program never exits (because there is no operating system to return to). It must loop and execute forever. ------------------------------------------------*/ while (1) { P1 ^= 0x01; /* Toggle P1.0 each time we print */ printf ("Hello World\n"); /* Print "Hello World" */ } } Thanks.