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I found the problem. The psen pin was not joninted with the iron, i found it only with the dvm as you suggested. I am sorry. Thank you very much for your support. I just started yesterday to enjoy my first 8051 based circuit.
Thank you again.

Francesco Fontana

No way, I followed the instructions in the errata sheet about P89C51Rx2 page 3 i guess, title:

FUNCTIONAL DEVIATIONS OF P89C51RX2 /01

I did the connection as shown in the two circuits. Vpp pin connected to +5 throw a 3,3 K resistor and to ground throw a 10 uF capacitor. And i connected Psen pin to +5v throw a 10 uF capacitor and to ground throw a 3,3 K resistor. The circuit of the the reset pin is the same of the an461 i only used a 4148 diode instead of the one used in the circuit. The cristal is a 12 MHz. In the meantime i "burned" another chip with a program that make the led blinking just to be sure that the circuit is running the program loaded. Should i increase the value of the two 3,3 K resistor to a 33 K as i read somewhere in the forum. May i send you the schematic of the circuit i am using?

Thank you

Francesco Fontana

I managed to download a simple program in a   P89CRC2BN using Flash magic but now I can