The original question concerned pal tv sets and as Karlos said, the 100Hz will do this because they use double-buffering like a Flicker-Fixer does!
I recall that Lowe and other German sets had models with this feature.
Standard tv sets use a 50Hz refresh rate that allows only HALF the scan-lines to be written each go. Interlacing allows the between scan-lines to be written.
clariSSA was an Amiga animation application that allowed animation-frames to vary at EACH half-frame, and thus produced SMOOTH movement at 640x512/640x400 formats.
