I have an existing design with external RAM mapped from 0000 and a lot of units manufactured. To rectify some intermittent errors in the original code, I need to gain a bit more RAM without modifying the hardware, so I want to use a chip with some internal XDATA memory in it. 1) How do I define which variables are in internal XDATA and which are in external XDATA since the addresses are the same, and MOVX is used in either case. 2) How do I specify the switch mechanism between internal and external XDATA since they are chip dependent (I know that e.g. Winbond and Philips use different mechanisms). Erik