I'm using a philips emulator and it's emulation software (PDS51) as well as the latest Keil 7.07a compiler. I've added "startup.a51" to my project. According to my emulation software, the P89C66X has configuration bytes at 0FD0h. This is where one would tell the core what type of clock (exernal, internal, etc), brownout voltage, etc. As I understand it, if I were to place these configuration values in my startup, they would directly transfer when I import my omf into the emulation sofware. I have looked all through Philips documentation and nowhere do I see these configuration bytes specified. Anybody know what they are? Or where I can find them? Thanks Javier