There are (possibly) two versions: One that does require a power supply input, and one that doesn't.
(This is guessed, using information fragements found in the adverts and on photos - it's also possinle possible that there was only one version)
The original version was first advertised in April 1985, these adverts didn't mention whether or not it requires a power supply input (normally, its data latch should need a power supply).
A year later, in April 1986 newer adverts included a note that a power input isn't required, which may refer to a new version, and which may mis-use the signal levels as supply voltages - if so, it may require some programming cautions (such like not to switch all signals to LOW level for longer periods), accordingly it may be incompatible with software from the older version.
Below are two photos, one showing a power-supply inputcable, one not showing one. Both have 34pin connectors, so both are probably printer-port-related hardware (although the photo with power cable is claimed to show a [[KDS Serial Interface ]] with 50pin connector, which is obviously nonsense).
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