Hi Kai,

You are right, it is better to tied them with resistors to +5V. But in our case here, that will not change the result (all 1's at P0 pins instead of the internal programmed byte).

About brand new ones, I said that they all worked fine on the new programmer (ALL-11 that I borrowed :) )

My question is:
Is reading AT89S51 static or not? It seems it isn't though it is static for AT89C51.

Kerim