On the MC68000 a copy of the processor condition codes can be obtained
with the MOVE SR,<ea> instruction.  On MC68010 processors and up however,
the instruction MOVE CCR,<ea> must be used.  Using the specific MC68000
instruction on later processors will cause a 680x0 exception since it is a
privileged instruction on those processors.  The GetCC() function provides
a processor independent way of obtaining a copy of the condition codes.
For all processors there are 5 bits which can indicate the result of an
integer or a system control instruction:

    X - extend    N - negative    Z - zero    V - overflow    C - carry

The X bit is used for multiprecision calculations. If used, it is copy of
the carry bit.  The other bits state the result of a processor operation.

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