This is my Tektronix 453 oscilloscope being used as a miniature vector monitor for Atari Tempest. It took a bit of fiddling to figure out what settings I needed to put on the scope to make this work so I took a picture so I could easily reference it. There's supposed to be a Z input which would control the brightness but I couldn't get it to work. Either because my probe was flaky or because the levels from the board didn't match what the 'scope was expecting.