Category: <b>serial I/O</b>
<p>
<pre><b>INT FD - TFPCX - TEST FOR CHARACTER WAITING</b>

	AH = 01h
Return: AX = status
	    0000h no characters waiting
	    0001h character available for input
Program: TFPCX is an interface between modem and terminal program for packet-
	  radio communications
SeeAlso: AH=02h
</pre>