INT 21 - DOS 1+ - WRITE CHARACTER TO STANDARD OUTPUT                            
	AH = 02h
	DL = character to write
Return: AL = last character output (despite the official docs which state
		nothing is returned) (at least DOS 2.1-7.0)
Notes:	^C/^Break are checked, and INT 23 executed if pressed
	standard output is always the screen under DOS 1.x, but may be
	  redirected under DOS 2+
	the last character output will be the character in DL unless DL=09h
	  on entry, in which case AL=20h as tabs are expanded to blanks
	if standard output is redirected to a file, no error checks (write-
	  protected, full media, etc.) are performed
SeeAlso: AH=06h,AH=09h