Hi, I'm just switching over from Atmel AVR's to work on a project that involves working with AT89C51SND1 micro. Perviously, I've used Atmel's CodeVision Compiler and now switching over to Keil. I have very few basic questions that I need help with, regarding the comipler. As I understand that to declare a port as an input in Kiel, the format is: P1 = 0xff; // (Entire Port 1 is Input) what i'd like to know is if i want to read a pin value on P1, how do i do it? is it... some_variable = P1; because in CodeVision it is as following: some_variable = PINA; and similarly how to write to a port, is it: P1 = value; in Codevision it is: PORTA = value; I've downladed some exmaple programs of the keil website and they've been helpful, but just want to confirm if i'm on the right track. Thank you