Can I ask a favour from someone with a fully working Mac LC and a scope? The original model, not LC II of newer. I need to know the voltage of logic 1 on the address bus. To do what, with the Mac off: 1. Plug scope ground to the PDS pin in the middle row closest to internal SCSI port; 2. In the same row, advance two pins and connect scope probe. See image. This will probe A17. 3. Power on. You will see the signal changing. I need to know the voltage when signal is high. #retroApple