Philips annonced new 51-based chip 8051MX. "With the introduction of the 80C51MX Memory eXtension, Philips Semiconductors has extended the 80C51 architecture to support more than 64 KBytes of on-chip memory. " And they tell about KEIL support of this chip. "Keil Software recognizes the market demand for an extension of the current 80C51 beyond the 64K byte barrier and will provide a complete tool chain to support Philips Semiconductors 80C51MX Memory eXtension," said Reinhard Keil" I was unsuccessful to find full DATASHEET of 80C51MX, only advertisement, like:
Have you asked Philips, or your friendly neighbourhood distributor?