I seem to recall one could damage a computer easily by interfacing through the p... | Hacker News

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		_femp on March 29, 2015 \| parent \| context \| favorite \| on: Home Electrical Device Control How-to (2003) I seem to recall one could damage a computer easily by interfacing through the parallel port without isolating correctly... Doesn't look like this guide covers the pitfalls.

Gracana on March 29, 2015 [–]

There's a current limiting resistor and a back-emf protection diode across the relay coil, that's nothing fancy but it ought to be enough.

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