MOVing between two memory addresses

I'm trying to learn assembly (so bear with me) and I'm getting a compile error on this line: ``` mov byte [t_last], [t_cur] ``` The error is ``` error: invalid combination of opcode and operands ``` I suspect that the cause of this error is simply that its not possible for a mov instruction to move between two memory addresses, but half an hour of googling and I haven't been able to confirm this - is this the case? Also, assuming I'm right that means I need to use a register as an intermediate point for copying memory: ``` mov cl, [t_cur] mov [t_last], cl ``` Whats the recommended register to use (or should I use the stack instead)?