From my post at the Keil forum:

RE: isp programming at89c51rd2

My idea was to try to clear the BLJB, set the BSB to 0xFF, set SBV to 0xFC (all this by software when i send a commnad to the micro) and then generate a reset; that way the micro will go into bootloader and now I can run flip to program the chip.

I have been reading a little bit more and I think i will not be able to do this

you should be able to do it, someone has done it.

I will try to hunt up who, but have not much hope.

When I published NoTouch and "the backdoor" for the Philips P89C51Rx2's someone did exactly this for the Atmels These, of course are moot by now since the NXP 'V' chips automatically go into ISP.

I do not know if it will help you any, but NoTouch and "the backdoor" can both be found at the FlashMagic (esacademy) website

Erik

If you are the author of NoTouch for Atmel, please post the solution (in the FAQ?)

Also, if you are not the author, but have the code (and verified it) please post.

Erik