Category: DOS kernel

INT 21 - DOS 1+ - DIRECT CONSOLE INPUT

	AH = 06h
	DL = FFh
Return: ZF set if no character available
	    AL = 00h
	ZF clear if character available
	    AL = character read
Notes:	^C/^Break are NOT checked
	if the returned character is 00h, the user pressed a key with an
	  extended keycode, which will be returned by the next call of this
	  function
	this function reads from standard input, which is always the keyboard
	  under DOS 1.x, but may be redirected under DOS 2+
	although the return of AL=00h when no characters are available is not
	  documented, some programs rely on this behavior
SeeAlso: AH=0Bh