Hi, I am playing with demo version of the Keil µVersion 2.03 and the Infineon SK-167SR. Also , I am not very familair with in C, which makes thinks not easier for me. For me the problem is rather strange. During a debug session almost every thing is runining fine, but if i let the same programm run from the flash of the board it does not. here is (not) working code void main(void) { unsigned char num_str[6]; ... do soemthing ... write_string(num_str,1); } void write_string(char * s, unsigned char line) { unsigned int i; if (line == 1) LCD_CNTL = 0x80; wait(30000); for (i=0; i<strlen(s); i++) { LCD_DATA = s[i]; wait(300); } } During debuging this is working perfectly. It shows some data on a LCD, but the same program running from flash, writes "only" black squares on the LCD (the complete fist line on my 20*2 LCD). For me it is quite hard to find the reason for this behavior. thanks in advance, Thomas