Hi Erik

The distance betwen R0 pin and pull up is 3mm
for test nothing else connected, so very short line.
What I see is 2- 3 µsecond to 2/3Vcc and i don't think this all right.

All is the result of a change bevore I used a 80c32 with external ROM everything was fine if I ad external ROM to 89c52 everything is fine again, but It's the internal code memory I want to use. By the way The difference betwen 35cm leads and 3mm is none.

Thank's Peter