document updated 19 years ago, on Apr 5, 2006

The experts suggest that open-collector outputs are required, which requires 4 pins on the microcontroller and two diodes and two resistors.
Open Collector and Open Drain are the same thing
PIC microcontrollers only have one pin, RA4, that's open-drain.
Comparisons / Descriptions of open-collector vs. tristate: one, two,
Some random joe says something that I was suspecting, though I havta confirm this: common-collector may be just like tri-state, but missing the output-high state.