I don't understand why the name of this tread is "Video Out on the Lisa 1 and 2/5", All Lisa (AKA MacXL) models have a RCA video out connector, not just the 1 and 2/5.
It's just a mirror of the internal video signal, my guess is that apple intended this to used for attaching large displays/projectors for presentations. Today, everyone is used seeing to a powerpoint presentation on a large display, but in 1983 this was a very high tech compared to using slides or transparencies. Slides and transparencies were very time consuming and expensive to produce, and so was easy to justify purchasing an expensive mutlit-sync display for doing this if you did many presentations. Highlighting Lisa graphics capabilities, this could have been the Lisa's killer app from apples perspective in the early 80's, so it makes sense to me at least they put the jack in the design.
Rick
It's just a mirror of the internal video signal, my guess is that apple intended this to used for attaching large displays/projectors for presentations. Today, everyone is used seeing to a powerpoint presentation on a large display, but in 1983 this was a very high tech compared to using slides or transparencies. Slides and transparencies were very time consuming and expensive to produce, and so was easy to justify purchasing an expensive mutlit-sync display for doing this if you did many presentations. Highlighting Lisa graphics capabilities, this could have been the Lisa's killer app from apples perspective in the early 80's, so it makes sense to me at least they put the jack in the design.
Rick