Telephone switchboard

The switchboard saw the peak of its use in the 20th century before wider adoption of the electromechanical automatic telephone exchange.

For example, a private branch exchange (PBX) in a business usually has an attendant console, or an auto-attendant function, which bypasses the operator.

[1] The switchboard operated telephone instruments manufactured by Charles Williams, a licensee of the Alexander Graham Bell company.

Thus, on September 1, 1878, Boston Telephone Dispatch hired Emma Nutt as the first woman operator.

Small towns typically had the switchboard installed in the operator's home so that he or she could answer calls on a 24-hour basis.

In 1894, New England Telephone and Telegraph Company installed the first battery-operated switchboard on January 9 in Lexington, Massachusetts.

Early switchboards in large cities usually were mounted floor to ceiling in order to allow the operators to reach all the lines in the exchange.

Late in the 1890s this measure failed to keep up with the increasing number of lines, and Milo G. Kellogg devised the Divided Multiple Switchboard for operators to work together, with a team on the "A board" and another on the "B".

As telephone exchanges converted to automatic (dial) service, switchboards continued to serve specialized purposes.

With this the BOCs took intraLATA call traffic from AT&T as well as services which were once provided on a cordboard (Toll Stations, Mobile and Marine [Ship-to-Shore]).

On the table or desk area in front of the operator are columns of 3-position toggle switches termed "keys", lamps, and cords.

The rear key on older "manual" boards and PBXs is used to ring a telephone physically.

On newer boards, the back key is used to collect (retrieve) money from coin telephones.

When a key is in the normal position an electrical talk path connects the front and rear cords.

The supervision lamps light to alert the operator when the parties finish their conversation and go on-hook.

Either party could "flash" the operator's supervision lamps by depressing their switch hook for a second and releasing it, in case they needed assistance with a problem.

In less densely populated regions, calls from payphones were handled by normal assistance operators without the use of dedicated coin boards.