tvcase DEPRECATED

	tvcase(kbcase.l2.r)

	This routine will enable or disable the ability to type lower/upper
	case characters on the color TV from the keyboard.  kb_case can be 
	TV_UPPER_CASE_ONLY, TV_MIXED_CASE, or TV_LOWER_CASE_ONLY.  The default
	at program initialization is TV_UPPER_CASE_ONLY. The ability to write 
	upper/lower case characters is not affected in 	any way.

	This function requires the following include files:

	clib_h

	Related functions:

	tvrkba