0 a piece of equipment that is connected to a computer so that the computer can run a particular piece of software or can use wireless broadband
1 a device that is attached to a computer that enables the computer to run a particular piece of software, or that can be used in other ways, for example as a wireless adapter
Programs that use a dongle query the port at startup and at programmed intervals thereafter, and terminate if it does not respond with the dongle's programmed validation code.
Thus, users can make as many copies of the program as they want but must pay for each dongle.
Cloners are also using "dongles", which are about the size of a matchbox and can be used rapidly to reprogramme and change the identity of a stolen telephone.
A second dongle is required for additional buzzers (for 8 player games).
It is also dubious whether the dongle produced higher quality sound, since the music did not feature any more channels than regular sound-chip music.
The motherboard can determine if the dongle is plugged in by examining the logic level on pin 4.
A simpler and even less secure option is to use unpartitioned or unallocated storage in the dongle to store license data.
A developer can also use the dongle to store user settings or even a complete portable version of the application.