On Mon, Jun 20, 2016 at 07:12:35AM -0400, Noel Chiappa wrote: [...] > Although how a monitor is supposed to tell whether a signal is interlaced, or > non-interlaced, is not clear - there's certainly no pin on the VGA connector > which says so! :-)
It's encoded in the sync signal. The timings are tweaked such that the beam of a dumb CRT will be pushed down a half-line on alternate fields.
