Hi Hans

I am using Atmel 89C52. R/W is gounded. Same Program with a change in address to 0x4000 as lcd data is working fine. my problem is only with Port P1. And i don't have a scope.

Mean while i have introduced 500ms delay for each command to lcd. and P1, EN and RS are connected to LEDs. E and RS are going high and low as per program. but P1 pins are not changing at all !!. i am writing a message in a while loop. so data pins of lcd should change for each character. it is not happening.