INT 62 u - FGDRIVER v3.03+ - "FG_CIRCLE" - DRAW UNFILLED CIRCLE
	AX = 000Dh
	BX = radius in horizontal screen space units (> 0)
Notes:	the FGDRIVER functions are rearranged with each major release, but
	  their parameters do not change (see #03474)
	The circle is drawn in screen space, centered at the current graphics
	  cursor position
	This call is ignored in text modes
SeeAlso: AX=0006h,AX=0008h,AX=000Eh,AX=0026h,AX=0093h