INT 2D - FREEVER - GET ORIGINAL DOS VERSION INFO

	AL = 12h
	AH = AMIS multiplex number for FREEVER
Return: AL = FFh if successful
	    BH = major DOS version
	    BL = minor DOS version
	    CH = DOS version flag
	    CL = OEM number
	    DH = major DR DOS version number (FFh if unknown)
	    DL = minor DR DOS version number (FFh if unknown)
Program: FREEVER is an AMIS-conformant freeware DOS version-faking TSR similar
	  to SETVER for any DOS-compatible OS, written by Matthias Paul
SeeAlso: INT 2D/AL=13h"FREEVER",INT 2D/AL=14h"FREEVER",INT 2D/AL=17h"FREEVER"