Hi Shankara,

1.
You tell not, which 87c51 /89c51 derivate you use.
Maybe it can help, use another derivate (Atmel, Philips, Intel, ...).

2.
This behavior was not faulty, since the state of any pin was only defined after 24 crystal cycles after reset was applied.

3.
Put a 100 Ohms resistor in series to the input, which should limit the strong current to a safe level, but not disturb the logic level.


Peter