Picture in this photo are three sets of connections.
1. The first connection set is a wired control-in/out connection that allows the connection of IR repeaters to allow the 91TXH to control several components.
2. Next is the iPod connection - this input accepts a special iPod connection cable that is provided with the 91TXH.
3. The other connection pictured is the RS232 connection. This allows you to display the graphic results of the MCACC (Multi-Channel Acoustic Calibration System) on a PC. This procedure is explained in the user manual.