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1541 Write Protect Hack?

I'm trying to learn a bit more about this crazy 1541 drive that I have. This is the same one I tested out at the August PDXCUG meeting. It has what appears to be a write protect bypass switch on the front (which is an old broken toggle switch), which seems at least partly hooked up to this.... What is THIS? Has anyone ever seen anything like this?

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rmzalbar 10/8/2020

Yeah, looks like the write protect hack. A bit over-implemented there. In addition to the switch, diode, and resistor there should be an electrolytic cap in there somewhere. The charge time of the capacitor allows the write protect to 'blip' briefly when sliding disks in and out but always return to the write-enabled state. This way the drive will know that there was a disk change, but will still leave the write protect disabled. The switch needs to be 'on' for normal write protect function, so if yours is broken then you have no write protection.