Who sees my stupid mistake?

[Ioannis]

Instead of this

  if PORTB.0 = 1 then   '<---- this line?
    Serout2 PORTB.7, 16384+12, [144, 44, 127]    ' Rewind
  endif

try this

  if PORTB.0 = 1 then   '<---- this line?
    High LED
    Pause 100
    Low LED    ' Rewind
  endif

Set LED to a Port and see if it blinks.

Ioannis