MDT.EXE is a DOS executable "Serial Debug Terminal" to which I have added
the ability to send BASE24 packets.

You can predefine packets in the text file MESSAGE.MDT, it's format
should be pretty obvious;
  - Lines beginning with ';' are ignored (comments)
  - Blank lines delimit message blocks
  - The first (non-';') line is the packet header (including SOH/STX)
  - The remaining lines define up to 24 FID's. ETX must be the last line
    (Note, if you need more than 24 FID's, you can put multiple FIDS in
    one line. Each line should not exceed 80 characters).
You can define up to 10 preset packets to send.

When you run MDT, you will have to be connected to a modem, and dial the
number by hand ("ATDT..."). Once connected, you will see the ENQ's
coming back as the host attempts to innitiate a session. Press F8 and
then select the packet number to send 1-10 and press ENTER. The packet
will be sent, and you should see the response from the host. To send ACK,
EOT etc. Press F1, then select the character you wish to send and press
ENTER.

You can edit the message fields "on the fly" by pressing F7 and then
selecting the message. Once in the field editor, you can press F2 to
edit the header.

A couple of notes:
 - The LRC is calculated across the entire packet, including the first
   character. To "eliminate" this character, the initial LRC value must
   be set to the same value. Ie: if sending STX (02), set the inital LRC
   to 02 ... Use F3 in the field editor to set the initial LRC. When
   loading MESSAGE.MDT, MDT automatically sets the initial Lrc to the
   value of the first character in the header.

 - MDT fills in the DATE/TIME fields with the current date/time. If you
   want to use a time hard-coded in the header, press F4 in the field
   editor until it reads 'Time[TXT]', Pressing it again to get 'Time[NOW]'
   will revert to sending the current date/time.

 - Don't include extra spaces at the beginning or end of the field lines
   in MESSAGE.MDT - these will get included in the packet being sent.
