I purchased an sd2iec from a guy in poland. The thing works well. But, I can't swap disks. I found out other people had this capability on theirs...but why didn't mine? I reached out to this guy and get sent me a picture of the board and that there are ares for drive 1, and drive 2. I guess I have to solder some kind of switches here, but I'm not sure what kind. momentary? on/off? I really don't know. Any suggestions?