Category: <b>video</b>
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<pre><b>INT 10 - VIDEO - ALTERNATE FUNCTION SELECT (PS, VGA) - VIDEO REFRESH CONTROL</b>

	AH = 12h
	BL = 36h
	AL = new state
	    00h enable refresh
	    01h disable refresh
Return: AL = 12h if function supported
Desc:	specify whether the contents of video memory should be displayed on
	  the screen; disabling refresh effectively blanks the screen
Note:	when display refresh is disabled, the entire screen displays the color
	  specified by the DAC color register 00h; thus to actually blank the
	  screen, the application must first ensure that that register has been
	  set to black
BUG:	GEM/VIEWMAX ET3000 and ET4000 drivers dated 1988/6/23 do not correctly
	  reenable refresh after the screen has been blanked due to inactivity,
	  resulting in a total loss of video synchronization
SeeAlso: AX=BF05h
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