Strange powering of the TL710 comparator

Question

I have an old schematics of 80th fancy synthesizer VCO. It uses the TL710 comparator, that according to the datasheet has -7V Negative Supply Voltage. I cant find the emitter-base breakdown voltage of EN5179. For me, it looks like it is used as a Zener diode. The EN5179 is almost impossible to find. So the question is: may I use 7.1 or 6.8 Zener for negative supply of the comparator? Or there is a trick that I don't see?

Answer 1

may I use 7.1 or 6.8 Zener for negative supply of the comparator?

Yes

Or there is a trick that I don't see?

V- current 5 to 9mA

No just do not exceed -7V