Strange VT50 Decscope

It looks like some kind of prototype. I'll open it up tonight or tomorrow to see what it looks like on the inside. I'll try to get some more pictures. Here's what the previous owner told me when I asked him about it. It sounds like it worked for him for 6 years. "I worked for DEC in the late 70's early 80's as a software engineer on the PDP10/PDP20 mainframe computers. I was given this terminal so I could work from home. When I left DEC they did not want the terminal back. So I've had it all these years. We plan to sell our house so I am doing some major house cleaning, selling on Ebay, garage sale, etc. I would say the last time it was used was around 1984. I used it frequently for about 6 years, so 1978->1984. Has not been plugged in since 1984!" Ashley http://www.woffordwitch.com