hi Eric,

I am currently using the AT89C52 and I want to migrate to the P89C51RD2. I am concerned that I will inadvertently overwrite the bootvector!

There have been posts in the past which claim that this chip is jinxed :-) Which really scares me!
http://www.8052.com/forum/read.phtml?id=34831
http://www.8052.com/forum/read.phtml?id=31057

you state in your NoTouch doucment "...While it is a fact that an EMI caused scramble of
a specific flash location ( boot vector ) would disable this the statistical likelihood of being unable to perform ISP is greatly reduced. I do not understand why Philips when they did the right thing by using ROM rather than flash for the bootloader did not hard code the boot vector to avoid this problem..."

Surely i could with some dumb programming :-) manage to overwrite the Boot Vector or so i gather form the backdoor doucment.

I have access to an universal programmer, which can parallel program the P89C51RD2. Is it possible to reprogram the bootvector location using the parallel programming technique? Or is the chip good only for the trash can?

should i parallel program the chip the first time, introducing your code for touchless ISP, and then consequently start using ISP?

I haven't started using the P89C51RD2 yet!

please advice,

Sushil