Binary/Legends

Binary, also known as Droidspeak, was the droid language composed of electronic beeps, bloops, buzzes, chirps, whines, and whistles. All droids could "speak" and understand Binary. Some people—such as Revan, Meetra Surik, Kit Fisto, Atton Rand, Bao-Dur, Anakin Skywalker, Cade Skywalker and Luke Skywalker, Wat Tambor, Droma, Kyle Katarn and Corran Horn—spent so much time with (their) droids that they acquired some fluency in the language, although they were not able to synthesize it. Generally, a whistle ascending in pitch was an affirmative, and one descending in pitch was a negative. It was sometimes possible to understand Binary from the pitch in which it was spoken—notably, expert slicer Zakarisz Ghent displayed an ability to understand the language almost perfectly. It also consists of a type style that spacers, pilots, and officers often use to identify themselves when speaking to droids via computer databank as well as to ask for safe passage to certain planets to let officials know their ID is authentic.

History
Preceded by the archaic CBell-1, the droidspeak standard was established by Industrial Automaton's line of astromech droids. It later became the standard mode of communication for droids from many manufacturers, all of whom paid IA a small licensing fee to use the language.

The father of modern droidspeak was considered to be cyberphilologist Yperio Baobab, of the prestigious Baobab family. His program, created circa 200 BBY, allowed droids to communicate much more complex concepts than "yes" and "no." With Bab-Prime, as it was dubbed, droids could recall and pass on sensory-gathered data between one another. Some time later, a cybersociologist working for the Baobab Merchant Fleet added a layer of code to the programming which gave droids an "essence of personality." Consequently, this code acted like a rampant computer virus that spread across the entire droid population. Droids then began to exhibit personality traits ranging from arrogance to comradeship. As a result, droidspeak flourished and transformed from Bab-Prime into Bab-Neo, or "Babno" as it was known. While some droid owners preferred this new mode of interactivity between droid and master, others chose to wipe their droids' memory clean of this personality code.

Replicating droidspeak
Even as Basic and other widely used languages could be interpreted by droids, there were cases where a being might need to communicate with a droid in Binary. This varied by class and model, and typically those falling under the 0500 to 0999 class were capable of understanding. Models outside this class range would ignore Basic or any sounds or even sign language the being might make. A droid that understood Basic might only be programmed to respond to the voice of its master, and by communicating exclusively in Binary, outside interference that might affect the droid's behavior or function could be limited during the conversation.

In order to assist communication with droids, reed whistles like the Baobab Larynx-7 were created. With some practice, all the necessary chirps, whistles, and buzzes could be replicated.

Some examples of phrases are given below.
 * A four-note beep with a step down from the first note, then the last two notes each higher in pitch than the first ("Can you help me?")
 * Make a single, one-second rising note beep. Beeeep! ("Turn on the power.")
 * Make a single, one-second falling note beep. ("Turn off the power.")
 * Make a six-note chirp, falling in pitch in the middle of the notes and forming an interrogative envelope at the end of the statement. ("Where is your master?")
 * Give a two-note chirp, and hold up your hand, palm open. ("Stop!")
 * Make a series of short buzzes with your tongue. (Your buzzing should be at a pitch distinguishable from those of electrocution.) ("Lower the voltage. You are damaging my molecules!")
 * Four equal-pitch buzzes. ("Can you repair this?")
 * Make a two-note beep and tap on the door. ("Open the door.")
 * Make a single beep and tap on the door. ("Close the door.")
 * Make a series of high-pitch "whoops". ("Please help me.")
 * Make a long, sirenlike wail. ("Emergency!")
 * Create a staccato series of short rising whistles. ("Get help!")
 * Make a sound resembling the noise "ank" and shoo the droid away. ("Leave me alone. I will do it myself.")

During communication, statements were to remain scientific and straightforward in nature.

Behind the scenes
There is no apparent relation between the Binary of the Star Wars universe and the numeral system with that name in the real world which forms the basis for all modern computer architecture.

Different sources demonstrate a discrepancy on when droidspeak was invented: droids of Revan's era (in Knights of the Old Republic) like the T3-series utility droid were using droidspeak more than 3000 years before Yperio Baobab's alleged invention of the language in 200 BBY.