Category: <b>BIOS</b>
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<pre><b>INT 16 - KEYBOARD - CHECK FOR 122-KEY KEYSTROKE (122-key kbd support only)</b>

	AH = 21h
Return: ZF set if no keystroke available
	ZF clear if keystroke available
	    AH = BIOS scan code
	    AL = ASCII character
Notes:	use AH=09h to determine whether this function is supported
	some versions of the IBM BIOS Technical Reference erroneously report
	  that CF is returned instead of ZF
	K3PLUS v6.00+ supports this function as an alias of AH=11h
SeeAlso: AH=01h,AH=09h,AH=11h,AH=20h,AH=21h
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