a system for programming / controlling various audio / video devices coupled to one another via a bus structure , through the use of a single macro key utilizes an addressing structure . each various audio / video device includes memory and a processor / controller for the memory and bus management . the memory is divided into master data memory and slave data memory depending on the role of the audio / video device . data transfer over the bus only contains dummy numbers that are used as macro command addresses , with the macro data itself processed and stored in the various audio / video device . this eliminates the need to store the different commands of the various audio / video devices in the device chosen to initiate the macro . for each macro , one audio / video device is the master device while the remaining audio / video devices are slaves .