[Bloody Sam Roberts]

I've always wondered why the Master/Slave nomenclature persisted in the IT industry. The syntactical norm would be Primary/Secondary.

I don't care one way or the other but consistency in naming conventions always makes things easier.

[astyanax]

Primary and secondary are already used in reference to the controllers and each controller can support two devices.
Hence primary master and primary slave are the two devices on the primary controller, secondary master and secondary slave are on the secondary controller.