The 516 Area Code in Detail
936 and 999 were former Dial-It mass announcement services.
903 was a former area code for Mexico.
233 was an unconfirmed former exchange for Selden.
440 plus any four digits used to connect to police emergency (911).
In the 516 area code, it's currently not necessary to dial a "1" before any calls. This makes scanning it easier.
In other area codes, "1" plus a number may do something entirely different than the same number without a "1" in front of it. Because 516 doesn't require a "1", it's impossible for any number that is an area code to also be used as an exchange.
This scan was done from our office in the 751 exchange. We believe it to be at least 90 percent accurate. If you know of any corrections, please forward them to us.
In cases where we were not absolutely certain if an office was 5ESS or 1AESS, or a DMS-100, the generic term "ESS" is printed.
It you wish to do a similar scan from your area code, we would be happy to print the results. But you must be thorough. First, go through your phone book and mark down where each exchange is listed as being from. If your phone book doesn't list every exchange in your area code, you'll have to find the other books. This list of locations is not the location of the central offices. Getting that will take some engineering and ingenuity yon your part.
Sometimes test numbers exist that identify the location and type of a central office (around here it's XXX-9901).
You must also be able to tell the difference between generic ESS and crossbar. 516-751-9970 is a crossbar busy. 516-360-9970 is an ESS busy. But 516-423-9970 is a crossbar busy, even though i sounds very much like an ESS busy. You can tell because the relays click on both sides of the busy. An electronic or digital switch has no relays and therefore doesn't click.
Once you have a list of valid exchanges and where they come from, you must see what all of the other exchanges that don't exist do when you dial them.
If your area code requires a "1" before some calls, you must try each and every exchange with and without a "1". This is how you find interesting features.
The final step is to see if the exchanges you have logged actually show up in the phone book. If not, odds are they are being used only by businesses or as a Direct Inward Dial (DID) for a large corporation or institution. DIDs contain many beepers, fax machines, computers, etc.
Two copies of this list, one sorted by exchange and the other sorted by central office name, can be found on 2600 bulletin boards.
Key