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> The pullup device was often a darlington rather than a npn and a diode
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I didn't think so because the output current was limited to ~B(3.6/Rc2). With a darlington there wouldn't be much current limiting (B^2 *3.6/Rc2).
They usually put a small resistor in series with the pull up device(s) for short circuit protection. 40 ohms as I recall for S. But the bible is at work.
Yes, the darlington and curent limters are clear in the drawings Spehro linked. I'd forgotten that piece.
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