The HAL Communications Corp HAL DS2000 KSR smart terminal. Click on image for larger view.
The manual refers to this BMC monitor, so I assume it was purchased along with the KSR unit. Click on image for larger view.
Here is a nice big pic of the boards and wiring view, with the case open. Click on image for larger view.
What's next? Attach it to a computer expecting a current loop as if the HAL were a Teletype. There is also Morse code and Baudout communications.