89C51RD2 does not identify your chip. However since you mention FLIP, I assume iyt is the AT or the T. If so, no one HERE will know, this is a FlashMagic forum. Find a Flip forum. If, however your chip is P89C51RD2 and NOT AT89C51RD2 or T89C51RD2, Flip will not work.
P.... = use Flash Magic
AT... = use FLIP
T.... = use FLIP
Erik