Computer memory refers to the storage of programs or data on a temporary or permanent basis. Memory devices can be classified into two distinct groups: primary and secondary. Memory chips may be ...

program counter (PC) - holds the memory address of the next instruction to be fetched from primary memory memory address register (MAR) - holds the address of the current instruction that is to be ...

Depending on the type of instruction, additional steps may be taken: If the instruction is to transfer data held in the ACC back to primary memory, the intended memory address is copied into the MAR.