Hi,
I used in my new design Philips P89C51RB2HBBD.
Oscillator freq. 11.0592MHz
I tried to use WINISP v.2.26
I connect P2.7 on high
PSEN on low
Vpp on +12
Vcc on +5
I do this and I enter into ISP.
I didn't change Boot Vector and Status Vector. Only Turn ON/OFF.
I couldn't enter into ISP.
I tried hardware reset, and I changed parameters on PSEN, P2.7&p2.6.
Nothing...
I entered finally. Everything was O.K.
I tried again TURN ON / TURN OFF and everything was same...
Goran