Beg thy pardon?

When factory fresh, the Rx2 of any kind and manufacturer goes into the bootloader directly and does nothing but wait until somebody sends the 'U'. It does not start to transmit without receiving.

However, in P89C51Rx2H (and obviously also non-H, just I have none to try) - if bootvector "is lost" but the chip is erased (which means it is not absolutely factory fresh anymore, but might got into this state e.g. because of RC reset induced bootvector loss without actually being programmed), in RD2, the FF's got executed up to the bootloader start; in RC2, as there is a "gap" with no flash, I-don't-know-what-happens, maybe it starts transmit spontaneously...

Not that it matters too much; bootvector lost so the chip needs treatment anyway...

Jan Waclawek

PS. OF COURSE the real solution would be to throw it away and get a P89V51Rx2, but again, I doubt OP can do that easily...