then use an 89C52RD2 and FlashMagic
My suggestion, but higher up you countered it with
True, but if he has the 8052AH-BASIC, you can only program the external EPROMs

By the way, if you want to use FlashMagic (an excellent choice) you need the P89c51Rx2 (x = B, C or D depending on flash size).

Erik