The "COPY" command(key3) copy the "memory" contents of the master IC to the slaves.
Other extra information in the master chip will not be copied. Instead, some of them are
taken from the settings done by the user.

Before copy, the blank status of every slave was checked (and be erased if required).
Unless all the slave ICs are in blank status(and an empty socket is), the write action
will not proceed.

After copy, there might be some extra actions will be taken, such as writing the sector 
protection bits or configuration information, which depend on what device it is and 
what the setting on the programmer is.

At last, all the slave ICs will be verified with the master(actually, a VERIFY command
was issued) to make sure its correctness.