C51 7.0 supports dual DPTRs, at least in some major library routines. It also supports an extended DPTR. I'd like to be able to do both at once, to do block moves from far xdata to far xdata. It doesn't appear as though the Keil tools support dual far DPTRs, though. You can have two DPTRs, the first of which might be 24 bits wide instead of 16 and the second (if used) always 16. So, if I want a far-to-far memcpy, I'll be writing it myself. Is this conclusion correct?
The Dallas 390 Contigious Mode implementation does not use the XBANKING.A51 file. Instead the DPTR's are directly accessed. Please send your serial number to: support.intl@keil.com I will then send you the source code of the related routines.