I am using a P89C669 and I am confused about the internal SRAM. The data sheets say there is 2K of on-board static RAM but the user manual shows that only 768 bytes in the on board XDATA space. However if a P89C669 device is selected as the target processor the dialog box shows a check box labelled "Use On chip XRAM 0x00- 0x6FF" What's the story or is my brain finally going to mush?