INT 2F U - DOS 3.0+ internal - GET JOB FILE TABLE ENTRY                         
	AX = 1220h
	BX = file handle
Return: CF set on error
	    AL = 6 (invalid file handle)
	CF clear if successful
	    ES:DI -> JFTsee Job File Table entry for file handle in current process
Notes:	the byte pointed at by ES:DI contains the number of the SFTsee System File Table for the
	  file handle, or FFh if the handle is not open
	supported by DR DOS 5.0+
SeeAlso: AX=1216h,AX=1229h