Empty slot

The absolutely most accurate way is to open it up and look for an empty RAM slot next to an occupied one Another accurate and easier way is to

By using the proposed system one can preemptively know whether there is an empty slot or not by looking the LCD display outside the premises as

empty slot You don't have any attunement slots You need at least 10 attunement to get first slot Then you'll have

empty the bank slot PLC, cover, empty slot