inputs would have to be grounded, or "low" (0).
This circuit's truth table, then, is equivalent to that of the NOR gate:
In order to turn this NOR gate circuit into an OR gate, we would have to invert the output logic
level with another transistor stage, just like we did with the NAND-to-AND gate example:
OR gate with open-collector output
The truth table and equivalent gate circuit (an inverted-output NOR gate) are shown here:

Of course, totem-pole output stages are also possible in both NOR and OR TTL logic circuits.