I don’t really remember what motherboard I had. It definitely didn’t have dual sockets because the first PIII (Katmai) were Slot A devices. I even ran the utility to turn off the controversial unique serial number. I remember having all sorts of trouble after I replaced a processor because it turned out they had different steppings. I complained and made a pain of myself and eventually they replaced the existing unit with an equal stepping. Again, I can’t remember all the details.