I stiil do not understand why so many want to "create" bootloader programs. Both Philips (P89C51.. and 89C66x), Tem sorry Atmel (T89C51..) and if I recall Cygnal have chips with "hard" ISP code. Burning a bootloader into flash will work until you see that Murphys Law is true and you have to remove the chip from the board to make it come alive again. The advantage of ROM based bootloaders in flash chips is that you will not lose the ability to program the chip as long as the chip (NOT the program) is working. I am not very familiar with the other brands bootloaders but assume they are similar, anyhow in the Philips case if you destroy your flash by writing total garbage to it, you can still wake the bootloader up with a couple of clip leads.

Have fun, but remember Murphy was an optimist

Erik