Date   : Fri, 24 Feb 1984 22:45:02 EST
From   : Keith Petersen <w8sdz@brl>
Subject: MDM724 key string info

MDM724 update information

Sigi Kluger, El Paso TX  02-17-84

Being used to a great non-public modem program with a number of
function keys, I decided to add ten function keys to MDM7.  Great
for things you do most, like DIR *.* $U0AD, or XMODEM S, or you
could even save your name in a function key for logon.


1. HOW TO ACCESS (transmit) THE FUNCTION KEYS.

You transmit the contents of a function key by typing first the
INTERCEPT CHARACTER, then a digit 0..9.  The INTERCEPT CHARACTER
is a unique control character which tells MDM7 that a function key
command follows. The INTERCEPT CHARACTER is set to ^A (CONTROL-A).
In the distribution version, the following keys are defined:

^A0    DIR
^A1    DIR *.* $U0AD
^A2    XMODEM S
^A3    XMODEM R
^A4    BYE
^A5    CBBS

(Function keys 2 and 3 have no trailing CR).


2. HOW MUCH ROOM?

A total of 256 bytes are reserved for the function key definition.
Each definition takes up the number of bytes in the string, PLUS 2.
Note that you must not enclose any control characters in the
definitions (CR is allowed, though, and optional).


3. HOW TO CHANGE THE FUNCTION KEYS

In order to not increase the size of MDM7 considerably, I have written
the MDMFNK utility.  MDMFNK.COM is virtually self-explanatory and
covered by its own short DOC file.


4. WHAT WILL NOT WORK

Do not attempt to use DDT to modify the function keys.  Especially, do
not force any control characters into the definitions.  There can only
be three non-printing characters in each definition, the start byte,
an optional CR at the end, and the end byte.


5. DEFINITION FORMAT

This is an example of the definition for function key 1:

DB     1,'THIS IS A FUNCTION KEY',CR,0
       ^               ^             ^
       ^               ^             stop character
       ^               key definition plus CR
       start character

Each key definition string starts with the key number in binary.
The function key processor searches for that number.  Therefore,
those numbers must be unique throughout the key definitions.
EMPTY key definitions are encoded thusly:

DB     9,0             ;empty function key #9