Thanks all.
@CrossRoads: Just some clarification please on the zeners for limiting pin voltage to 3V (say). I can see how that's beneficial when the chip is powered but when it isn't that's STILL 2.5V above Vcc so is it going to achieve anything?
Thanks all.
@CrossRoads: Just some clarification please on the zeners for limiting pin voltage to 3V (say). I can see how that's beneficial when the chip is powered but when it isn't that's STILL 2.5V above Vcc so is it going to achieve anything?