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Mark1960 · 7th Jul 2021, 6:19 pm

I think in those cases the inputs would be driven from the 8154 or some other source, so the pull up resistor is no longer needed. The pull up resistors just make sure the inputs are not floating if disconnected from any other source and the switch is open circuit.

7th Jul 2021, 6:19 pm	#31
Mark1960 Octode Join Date: Mar 2020 Location: Kitchener, Ontario, Canada Posts: 1,294	Re: Ortonview PCB I think in those cases the inputs would be driven from the 8154 or some other source, so the pull up resistor is no longer needed. The pull up resistors just make sure the inputs are not floating if disconnected from any other source and the switch is open circuit.