As mentioned in this post in another thread  Login to view image However there is no official indication that this Beosound should have any link capabilities, and also the specifications in the start of the service manual says that pin 6 and 7 are not used. Login to view image My parents has this model of Beosound 1, so I have been able to do some minor testing to look into this. I have tried connecting a Beocord 3500 tape player and tried activating it with A.MEM which also activates the AUX connection on the Beosound 1, but no reaction from the Beocord. Just to see if the pins are even connected I tried to do a voltage measurement with a multimeter on pin 6 and 7 with pin 2 as ground. Pin 6 is reading 5.1V both in standby and when activating A.MEM. I am not seeing any fluctuations in voltage as I would on a datalink pin when a command is sent. Pin 7 Is reading 0V both in standby and when activating A.MEM, and also no fluctuations in voltage when a command is sent. I can’t really figure out if this has any potential use, or if it is just a function that was developed in hardware that newer got Into use in the final product. In terms of link room capabilities it is indeed only possible to set it in option 0 and 1. Any thoughts if this is just a dead end or something to pursue?