tvbrat DEPRECATED

	tvbrat()

	This routine sets the blink rate for the color TV.  RATE is the new
	blink cycle time expressed in units of 60 ms.  RATE should be in the 
	range [0-15].  The foreground pixels of blinking characters will be
	visible for half of each blink cycle and black for the other half.
	This routine is a dummy on VAX consoles.

	This function requires the following include files:

	clib_h