You may connect the 8MB ramdisk to your DUE via the External Memory Bus (Static 8bit memory) - 8MB Ramdisk (external RAM) for Arduino.. - Other Hardware Development - Arduino Forum
RDisk DUE (EMB signal names)
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D0-D7 D0-D7
NWR NWE
NRD NRD
NDATA Ax
With Ax = 1 you write the 24bit starting address of a block
With Ax = 0 you write/read the bytes sequentially from the address