PDSx000 pedals under the covers

[pcamann@csc.com]

To anyone on the list who knows the PDS2000 and PDS8000 pedals at a
circuit/schematic level:

Are the internals of these two similar, differing only in memory and
addressing circuitry, or do they differ markedly?  And do they use discrete
memory chips (like my RDS1900 and RDS3.6) or is the whole shooting match
embedded in a single chip (like the RDS8000 and the Boss DD5)?

Any input would be very welcome.  Thanks in advance.

Paul Camann