Introducing the Mac-O-Meter. An original creation by the CayMac Vintage Team. The item plugs into the external floppy port and displays the 3 main voltages (if available) being the 12v, 5v & -12v. There are 2 versions available: ** - Base unit with DB19 connector that plugs directly into your Mac floppy disk drive port. ** - Base unit with a miniDIN connector & the DB19 to miniDIN adapter. The adapter plugs into your Mac floppy disk drive port. A miniDIN cable runs between your adapter and your base unit using their respective miniDIN connectors. Cables used for connecting ADB keyboards are suitable for this task. ============ If you are using the miniDIN version, make sure that the base unit's miniDIN cable is only connected to the adapter 's miniDIN connector. The only port on the Mac that should be used for either version is a floppy disk drive port. DO NOT attempt to connect the miniDIN cable to your Mac's ADB ports, as it will not provide any useful readings (it is safe to do so, but useless). ============