INT 21 - DOS 1+ - WRITE CHARACTER TO PRINTER                                    
	AH = 05h
	DL = character to print
Notes:	keyboard checked for ^C/^Break, and INT 23 executed if detected
	STDPRN is usually the first parallel port, but may be redirected under
	  DOS 2+
	if the printer is busy, this function will wait
SeeAlso: INT 17/AH=00h