INT 21 - ELRES v1.0 only - INSTALLATION CHECK                                   
	AH = 4Bh
	DS:DX = 0000h:0000h
Return: ES:BX -> ELRES history structure (see #01381 at AH=2Bh/CX=454Ch)
	DX = DABEh (signature, DAve BEnnett)
Program: ELRES is an MS-DOS return code (errorlevel) recorder by David H.
	  Bennett
SeeAlso: AH=2Bh/CX=454Ch