How to dimension a slot in a drawing?

How Can I Check If a Memory Slot Is Faulty? & Upgrade dim slot ASUS ROG Maximus IX Apex Z270 slot ASUS ROG Maximus IX Apex Z270 uses a slot The motherboard doesn't have any slots on it interesting dimm2 slot Remove the replacement DIMM from the antistatic shipping bag, hold the DIMM by the corners, and align it to the slot The notch among the pins

dimm 2 slot in my design, witch of slot A and Slot B is Dimm #0 ? and witch of them is Dimm #1? let me know either Slot A should be placed furthest or