On Sat, 9 Sep 2000, Steven Hascall wrote:

> On the rear of my Apple MS 17 Display (where the video cable runs into
> the monitor), there is what appears to be a serial port. Can I do
> anything with it? What is it for?

It's most likely an ADB port.  MacOS uses this to read the
contrast/brightness controls so that it can pop up a window on the screen
indicating the current contrast/brightness.
-- 
Tod McQuillin