José,

Dallas says
1) "Bootstrap loader mode will not operate correctly if any of the lock bits (LB1, LB2, LB3) are set."
2)
To enter loader mode, port pin P3.7 must be pulled high when the pin biasing combination of RST=1,
PSEN=EA =0 is applied.

I will be try the loader next week so i will post the result in this thread.

regards,
p