Thanks for your answers.

89c668 seems to be a good chip. I'm looking for a distributor here in France.

I agree to say that even if external memories are connected, the ISP capability could be still implemented, by downloading a bootloader in the uC emmbeded Flash.
Nevermind, with 64kb, I suppose it could be enough for most of my applications.

As I wrote before, this board will be designed to match most of my applications.

Currently, I'm designing a VHF transceiver and I'd like to implement a graphic LCD.
But other ideas are waiting since a while and this board will be the common part for future projects.

The purpose for me is to design a board with several peripherals I could depopulate when it's not needed by the application. That's why I would not buy a commercial one for the moment.

Peter, I don't know what you're speaking about with the Keil capability to reduce the variable space. Could you tell me a little more ?

Regards

Stephane