Some things don’t change. Sometimes familiarity you shouldn’t mess around with.
In this case, the operator switchboard or Attendant Console as remained mostly the same since 1984, first released for the System 75 PBX. This model # was 302 series, but rarely is branded as such, only in the administrative terminal sessions to add stations and alike. There were 4 different series of 302s, suffixed with letters
A was the model shown below, very Merlin looking, and used button caps similar to Nortels, but more smaller.
B had a different display, with a white instead of metallic.
C replaced the button caps and supported 2 wiring environments. Prior to 302C, you needed the full 8 wires of copper to connect the console. C also introduced modular connections for the hand or headset. Prior to C, the console automatically logged in operators if they plugged in that dual 1/4″ jack into the console. Because of the change of jacks, the operator would had to press a few buttons to log them in.
302D was introduced around the turn of the century and required 2 wire environments only. 302C could work in ether/or environment
At some point, as of this writing in 2015, the 302 Series is officially dead and is no longer sold as new by Avaya as many operators have evolved to administrative assistants doing multiple things and split the calls between those groups, or in some operator environments have been replaced by s0ftware based sets. Operator sets don’t come cheap, and including its Direct Extension Selection or DXS can cost about $1,100 new!
The DXS has evolved, but the general idea hasn’t changed. In fact the Merlin looking industrial designed remained in tact right to the EOS. The first generation had 8 buttons on the very bottom acting as “Hundreds groups select”. Simply put, if you have dial plan from 4000 to 6000, the bottom 8 buttons would be labeled “40”, “41”, “42” and “53”, “54”. etc. So if you want to call extension 5138, you would hit the bottom “51” key from hundreds group, then press “38” in the 100 array keys. You can monitor a group of hundreds at a time and in later models as the System 75 evolved from supporting a few hundred extension into the behemoth of the Definity PBX supporting tens of thousands of lines, the Hundreds group keys maxed to 20, so you could monitor a couple thousands of lines if you had that model.
This picture is interesting because its very rare for any AT&T/Avaya Red publication to show exploded views of any of their equipment. This was standard operating procedure for Nortel if someone wanted to replace a part in a console or a set, however it was the job of AT&T to Lucent to Avaya to let this type of work be done by them or vendors.