> [TELECOM Digest Editor's Note: I know from my personal experience that
>> Illinois Bell had ESS in the Wabash office in downtown Chicago in
>> 1974, along with the Superior office on the near north side the same
>> year. But I think they were just the first editions or versions of
>> that type of switch. PAT]
> The Western Electric #1ESS was invented in 1965, with the upgrade
> #1AESS invented in 1976. These were analog switches with computer
> control (and in my opinion, glorified crossbar switches with reed > relays).
> Others, as I've mentioned before, came out with their fully digital
> switches before Western Electric came out with their fully digital end
> office switch (the #5 ESS) in 1982.
Actually WE came out with #4 ESS in the mid 70's. Of course the 4 was a toll class switch, but it was a truly electronic switch.