I agree with Craig - your code would be much clearer & more easily maintainable if you used an array of structures (see my reply to your cross-posting on the Keil forum!). It might even enable the Compiler to generate more efficient code?

In ANSI 'C' (and Keil C51 is an implementation of ANSI 'C') you can simply assign one structure to another; you do not have to "manually" write the memcpy call.

However, in C51, it might be advantageous to use the memcpy, since C51 can use a 2nd DPTR in memcpy - provided you have a suitable processor, and select the right compiler options.