I have an oscilloscope so maybe i can find out. A lot of the LCD monitors that shipped with VGA inputs accept sync-on-green via the VGA port, but i have some doubts about them accepting the signal from something like this without some additional sync rate conversion. I might have some ancient doodads for that too, somewhere. I used to buy weirdware speculatively. If i get my Plus up and running i will try and find out.
I bought this Plus some time in the early to mid 90's from a university surplus sale. I don't recall how much i did with it at the time but i am pretty sure it worked. It was modified to include a BNC port on the back. The BNC is on a circuit board that was potted in silicone caulking and wedged between the metal frame and the plastic back. It piggybacks the connection between the analog board and the digital board. With the availability of the blue scsi sd board at $25ish for the kit, i decided to try and revive this thing. I had oshpark make me a few of