The design (and the wiring of the circuit diagram) is able to adress 16 bit of memory....64K. But I don't think that the system will ever use 64K of memory. So i decided to only realise 10bit of adress logic...this means the program counter, the program counter help register (PC_HR), the +1 adder, 2 MUX , the adress register and the adressbus-register are only using 10 bit. In my calculation this saves me 84 relays, thats more than 10%. Thats not nothing.