> Then do one thing just write a small routine for toggling an LED and program your 89s52 an find out for your self if its working?

As I wrote here http://www.8052.com/forum/read.phtml?id=55531 I've already done a small test program for AT89S52 and it works in the same scheme. The difference between these programs is mostly in calculation part and in used RAM size. I suppose, that hardware is working properly. Of cause in calculation part could be mistakes, but I do not understand why it works on C52 and does not work on S52 :(