It is very similar to the ADuC, except a 128 bytes FLASH page rather than 64 bytes in the AD part. So I have to find some extra RAM and more of it for the Philips than for the AD. And the bootloader is in the lower part - I have to rearrange the parts concerning programming (well this is easy, but different from the others).

But which makes the P89V51RD2 very impractical is that it has only 768 bytes XRAM (they merrily claim "1kB data RAM", including the internal RAM); and this leaves mere 256 bytes for program data (512 bytes eats up the BASIC). The ADuC has 2kB XRAM, I think. From this respect the P89C668 is a winner with its unique-of-its-kind 8kB of RAM; however, the FLASH has to be erased in huge blocks, making the direct BASIC programming impossible.

SST has something very similar to the P89V51RD2 (I don't remember the marking at the moment), but it is not available here.

Nevertheless, I have a P89V51RD2 here and can try if I will have during the holidays (which I doubt, as my kids really require my presence...)



Jan Waclawek