Using the Chubby Gristle patch for testing (MSTE):

At 60Hz - the first four lines of text starting with D-Bug and ending with CJ are visible at all times.  The 'use 16Mhz' text is invisible nearly the entire time occasionally flickering into view for a split second.

At 50Hz - the first two lines of text are visible at all times.  The middle two lines and the 'use 16Mhz' prompt are all visible at some point but they alternately flicker in and out of view.