INT 62 u - FGDRIVER v4.02 - "FG_VBALLOC" - CREATE VIRTUAL BUFFER
	AX = 00CDh
	BX = width of virtual buffer in pixels
	CX = height in pixels
Return: AX = handle for virtual buffer, or
	    FFFEh out of memory
	    FFFFh virtual buffer table full
Note:	the FGDRIVER functions are rearranged with each major release, but
	  their parameters do not change (see #03474)
SeeAlso: AX=00CCh,AX=00CEh,AX=00D0h,AX=00D1h,AX=00D2h,AX=00D4h