The EH flag controls TECO's action when an error is encountered.

  Value  Meaning if Set

      0  Same as 2

      1  Only the 3-character error code is printed

      2  The 3-character error code and a short message are printed

      3  The 3-character error code, a short message, and a
         more detailed explanation of the error are printed

      4  The command(s) which lead to the error are printed,
         simulating the effect of the "?" command

  The 4 may be combined with either 0, 1, 2, or 3 in the EH flag