Examples of using positional information generally involve seeking to a particular physical location on the device. Since block drivers can store data in randomly-addressable fashion, they can be used to hold a LynxOS filesystem. LynxOS identifies devices using major and minor device numbers . The major number is assigned to the device automatically during the installation. A list of the installed major devices can be retrieved using the devices utility program.
Minor devices are only necessary if there are multiple minor devices for a major device.
For example, if the ADC only had one channel, we would not be concerned with assigning minor numbers. The kernel does not attach any special meaning to the minor number. The meaning is interpreted only by the device driver. The ADC, for example, has 16 channels which are numbered zero through 15. There is nothing to stop us from assigning the minor number 16 to channel zero, except common sense.