BBC Master
Econet Terminal
This is the underneath of the Master ET. None of the connectors are present, so this machine could not be used to connect to disc drives, printers, or 1 MHz devices or second processors.
It appears a bit strange that the auxiliary power connector is present given that nothing can be connected to this machine, but I imagine that this more to do with the fact that it was probably easier to make each Master with the same PSU rather than having ones with and without the power output.
In fact, the example in the picture above is one of two types of Econet Terminal because I have been a "Printer Server" version which has a printer port socket. I wonder also if the "Printer Server" version had a serial port at the back?
Photograph courtesy of Ken Hewson.