Interrupt 29h   (not documented by Microsoft) 
	   *    Internal - Quick Screen Output 
 
 This method is extremely fast (much faster than Int\21f\02 and Int\21f\09,
for example), and it is portable, even to "non-compatible" MS-DOS computers. 
 
entry   AL      character to output to screen 
return  unknown 
note 1) Documented by Digital Research's DOS Reference as provided with the 
	DEC Rainbow 
     2) If device\driver\ANSI.SYS is installed, character output is filtered
	through it.
     3) Works on the IBM PC and compatibles, Wang PC, HP-150 and Vectra, DEC  
	Rainbow, NEC APC, Texas Instruments PC and others 
     4) This interrupt is called from the DOS's output routines if output is  
	going to a device rather than a file, and the device\drivers
	struct -device attribute code word has bit 3 (04h) set to "1".
     5) This call has been tested with MSDOS 2.11, PCDOS 2.1, PCDOS 3.1, PCDOS 
	3.2, and PCDOS 3.3. 
     6) Used in IBMBIO.COM as a vector to Int\10f\0E (write TTY)
        followed by an IRET.