FixedRecordReverse[inFile_File, outFile_File, length_ : 80] :=
  Module[{inStream, outStream, line, byte},
    WithCleanup[
      inStream = OpenRead[inFile, BinaryFormat -> True];
      outStream = OpenWrite[outFile, BinaryFormat -> True];
    ,
      While[True,
        line = {};
        Do[
          byte = BinaryRead[inStream, "Byte"];
          AppendTo[line, byte]
        ,
          length
        ];
        If[byte === EndOfFile, Break[]];
        line = Reverse[line];
        BinaryWrite[outStream, line]
      ]
    ,
      Close[outStream];
      Close[inStream];
    ];
    (* Verify the result *)
    RunProcess[{"dd", "if=" <> outFile[[1]], "cbs=" <> ToString[length], "conv=unblock"}, "StandardOutput"]
  ];