INT 62 u - FGDRIVER v4.02 - "FG_FINDPAGE" - FIND AVAILABLE VIRTUAL/LOGICAL PAGE
	AX = 002Ch
Return: AX = first available page number (virtual or logical page)
Note:	the FGDRIVER functions are rearranged with each major release, but
	  their parameters do not change (see #03474 at AX=0000h)
SeeAlso: AX=0028h