ftp.barnyard.co.uk/2015.02.ftp.barnyard.co.uk.tar/ftp.barnyard.co.uk/cpm/walnut-creek-CDROM/BEEHIVE/COMMS/MEX4BEE.ARC/MEX10.DOC

Text File | 1990-09-20 | 62KB | 1,503 lines

          MEX: a Modem Executive for CP/M-80

        Copyright (C) 1984 by Ronald G. Fowler
              All Rights Reserved





1) Overview: What is MEX?

MEX is an acronym (sort of) for Modem EXecutive; its purpose is to build upon
the capabilities provided by various terminal emulation and file transfer pro-
grams written for CP/M-80.  MEX provides, in one program, a phone-number lib-
rarian and editor (supporting mnemonnic 12-character names for phone numbers
and load/save for phone number files), a powerful autodialer (allowing lists
of numbers to be called repeatedly until one answers with a modem tone; the
entire list may be repeated any number of times), a file transfer facility
supporting three common protocols (and "batch" file transfers), a "dumb-
terminal" emulator that includes the ability to dynamically define multiple-
line character strings under a single key (and save/load sets of keystrings
to and from disk files), a STAT command that allows you to examine and change
a wide range of operating parameters (especially useful with the CLONE command,
which allows you to save a new copy of MEX to disk, including any currently
defined phone numbers and keystrings), a batch-command file processor that al-
lows the program to take its input from a disk file (allowing unattended use
of MEX), and an on-line help facility (employing CP/M's random-access file
accessing functions for quick access) that completely documents the program.

MEX combines the capability of many public domain utilities, and is a super-
set of such programs as MODEM2, MODEM7 and MDM.  MEX provides more function-
ality than many commerical programs, and is gaining ground on the top-of-the-
line modem packages, such as Microstuf's Crosstalk (TM).  But enough horn
blowing ... let's get on with the Real Neat Stuff.


2) Getting started: the physical modem overlay

First, let me note that MEX, as distributed, contains no modem I/O at all;
it will run on your computer as is (in fact, you can do an initial evaluation
of MEX in this fashion), but commands dealing with the modem will elicit
an error message.  To be fully functional, MEX needs modem driver code (writ-
ten in 8080 assembly language) installed within itself; this driver code is
called the physical modem overlay.

If you're a user of Irv Hoff's MDM7 program, you have an easy progression path:
MEX uses a compatible overlay format, and thus almost any MDM overlay may be
loaded directly into MEX.  In fact, you can use the MLOAD program distributed
with MEX to install the overlay relatively painlessly (the use of the dreaded
DDT is not required).

If you don't have an MDM7 overlay, you'll have to write your own, or, if
you're not proficient in assembly language programming, find someone to write
one for you.  If you have to take this route, use the PMMI overlay distributed
with MEX (named MXO-PMxx.ASM, where xx is the revision level) as a model.
This file is a full-featured overlay, containing modem dialing drivers and
a fully functional SET command (SET is a user-defined command, used for such
things as baud-rate selection, answer/originate modem setup, etc).  You can
implement as little or as much of the "fancy stuff" as you like.  If you
re-distribute your overlay, please follow the naming conventions I've estab-
lished for MEX overlay files:  "MXO-nnxx.ASM", where nn is a 2-letter code
identifying the overlay, and xx is the revision level.

Once you have an overlay file, assemble it with ASM or MAC, then bind it into
the system with MLOAD.  The following example assumes you're using the PMMI
overlay; if not, just substitute the name of your overlay for MXO-PM10:

    ASM MXO-PM10                <<--- assemble the overlay
    MLOAD MEX.COM=MEX10.COM,MXO-PM10    <<--- load a new MEX.COM

If you have a Smartmodem (Hayes, USR, etc), you'll want to take advantage
of the Smartmodem logical overlay (MEX has no inbound Smartmodem code); this
overlay locates at the top of the overlay area (about 500 bytes from 0B00H),
and will work with any physical overlay that terminates before 0B00H (most
do).  It provides autodialing capabilities and, optionally, modem disconnect
facilities, using Smartmodem command strings.

Use the following example as a guide for installing the Smartmodem overlay
and your physical overlay simultaneously (the Smartmodem overlay is named
MXO-SMxx.ASM -- xx is the revision level -- and M7IN-3.ASM is the name of a
typical MDM7 overlay; replace the former with the name of your own overlay):

    ASM M7IN-3                <<--- assemble phys. overlay
    ASM MXO-SM10                <<--- asm. Smartmodem overlay
    MLOAD MEX.COM=MEX10.COM,M7IN-3,MXO-SM10 <<--- build new MEX.COM

(The order is important in the MLOAD command line due to the structure
of most MDM7 overlays).

Some notes about the preceeding discussion:

The version of MLOAD used MUST be 2.0 or greater; earlier versions didn't
have the ability to load a HEX file over a non-HEX file.

A very few MDM7 overlays are not compatible; such overlays are typified by
the requirement that they be revised with each succeeding revision of MDM7.
These overlays typically implement dialing facilities for unusual modems
(actually non-PMMI and non-Smartmodem), and require specific addresses with-
in MDM7 in order to function.  This was necessary because MDM7 does not pro-
vide a redefinable interface for dialing code (in spite of the overlay table
entry present for the dialing routine), and worked 'naturally' only with
Smartmodems and PMMIs.  As a result, the majority of overlays written do
not contain any dialing code, and thus will function correctly with MEX
(note that MEX allows a fully re-definable dialing vector -- see MXO-PMxx.ASM
for details -- and thus may be extended for use with virtually any modem).

3) Some precepts: Filespecs, string arguments, and multiple command-lines

Before detailing MEX's command set, there are a few topics we must address
that apply generally throughout MEX.

MEX supports the same drive/user specification for files as Rick Conn's
ZCPR and ZCPR2: A file may be prefixed by either the drive name, the user
number or both (this extends to batch file transmissions).

Examples:

        [MEX] A3>>SB B3:*.ASM A9:*.OBJ C6:UPDATE.DOC
        [MEX] A0>>DIR A12:*.SUB
        [MEX] B3>>TYPE 5:REPORT.DOC
        [MEX] C3>>T B6:SESSION.LOG


LOGGING DRIVES:  MEX supports relogging drive/user in two ways, both of
which are pertinent to a discussion of DU specifications:

   - LOG command: Takes optional DU spec (trailing colon optional)
                  resets disk system
   - At command prompt: simply enter the DU spec (colon required)

Examples:

                [MEX] A0>>LOG        (relogs current d/u: resets system)
                [MEX] A0>>LOG B:     (relogs current user, drive b, resets)
                [MEX] A0>>LOG B7:    (relogs drive b, user 7, resets)
                [MEX] A0>>B:         (logs current user, drv B, no reset)
                [MEX] A0>>A9:        (logs drive A, user 9, no reset).

Several MEX command take string arguments.  These strings must be sur-
rounded by quotatation marks, and may contain imbedded control char-
acters (with the singular exception of binary zero, which will generate
an argument error).  The caret ("^") is used to prefix a control char-
acter.

Thus, you can specify multi-line strings within one string specification.
Examples (note that that the control-character ^M is the carriage-return
code, and ^J is a linefeed):

        KEY A="BILL USER;J^MWHATSNEW^MB:^MWHATSNEW^M"
        SENDOUT "SD B:*.ASM^MCRCK *.BIN^M"

Additionally, the slant character ('/') may be used to denote several common
control-character sequences:

/R    specifies a newline (Carriage return code only; same as ^M)
/N    specifies carriage-return+linefeed
/T    specifies a tab
//    specifies the '/' character
/Onnn specifies any binary value (except 0): nnn is the decimal value (all
      three digits must be present)

Note that the command-separator character may be included freely within
a string; it separates your command strings outside of quotation marks
only.

MEX  supports multiple commands on a line, both in READ files, and in dir-
ectly typed commands.  A command line may optionally be entered on the CP/M
invocation command line, and this line may also contain multiple commands.
Note that a READ command will "stack" any current multiple commands; when
input from the READ file is exhausted, the remaining commands will then be
executed (a control-C at any time will abort a running READ file and/or a
multiple command line).

The multiple command separator in the file as distributed is the semi-
colon ";").  This character may be changed with the STAT command ("STAT ESC")
or in the patch file.

Examples:

   from CP/M:

        A>MEX DIR;READ MYFILE.MEX;SENDOUT "LOGOUT";BYE

        This example will bring up MEX, which will first print the directory,
        then begin executing MYFILE.USE, which may conain SENDOUT commands and
        R commands to send and receive files. When input from MYFILE.MEX is
        exhausted, MEX will send the string "LOGOUT" to the remote.  Finally,
        MEX will execute the "BYE" command.

   from MEX:

                A3>>COMMAND: RB;SENDOUT "BYE";BYE

        This one receives a batch transmission, sends the string "BYE" (grace-
        fully logout from a remote CP/M system, for example), then disconnects
        and exits to CP/M.



4) Terminal mode

MEX terminal mode is entered with any of the single-character commands T, L,
or E (the differences among the three will be explained shortly).

While in terminal mode, you are communicating with the remote end as a console;
your keyboard characters are transmitted to the remote, and the remote char-
acters are displayed on your screen.

There are several functions that are available to you from terminal mode,
all of which are invoked by typing the escape-character (do "STAT ESC" at
command level if you don't know your escape character) followed by one of
several characters; this combination is called an "escape-sequence".

Terminal mode escape-sequences:

<ESC>-E         exits back to command level
<ESC>-?         prints a menu of escape sequences
<ESC>-S         start copying incoming text into file buffer (see below)
<ESC>-U         end (un-start) copying text into file buffer (see below)
<ESC>-P         toggle copy-to-printer on/off (if enabled with STAT LIST)
<ESC>-T         transmit a file to the remote (prompts for a filename)

Note that <ESC>-S and <ESC>-U require a filename argument with the T when
you enter terminal mode (otherwise, there is no file active to write the
incoming text into).

You can use <ESC>-P to copy incoming text to the printer.  The text is held
in a buffer, and prints only as the printer is ready for a character. Thus,
your printer may be slower than the modem, and you won't lose characters un-
less the buffer fills up.

Terminal-mode files (also called CAPTURE or ASCII-SAVE files) are created
by entering a filename with the T (or E or L) command; if the file already
exists, you will be asked if the file should be erased. MEX will create the
new file, and enter terminal mode.  You may also append to an existing file
by specifying the "A" secondary option (explained in more detail later).

At this point, incoming text is not yet being saved; to start saving text,
you must use the <ESC>-S terminal-mode command.  You can stop the save by
using the <ESC>-U command.  You can perform as many start/stop sequences as
you like (when text-save is active, you'll see a colon at the start of each
line as a visual signal that the save is active).

You can exit terminal mode and move freely among drives and user areas with-
out affecting an open term-file. The LOG command (used to change drive/user
and reset the disk simultaneously) will not be functional.

If you enter terminal mode with the T,E or L command WITH a filename, when
a file is already open, the open file will be closed, and the new one opened.

You can transfer files using either Christensen or CIS protocols while a
TERM file is open -- your buffer may be written to disk to make room, but
nothing will be lost, and the file will still be open.

To close the file when you're done saving text, exit terminal mode with
<ESC>-E, and use the WRT command.  If you change your mind, and decide you
don't want to keep the file after all, use the DEL command to erase the
file entry and delete any text already saved in memory.

When your printer or ASCII-save buffer fills, MEX will send ann X-OFF char-
acter to the remote.  MEX will then wait for the remote to stop, and will
save up to an additional 150 characters into an auxiliary buffer (this buf-
fer may be increased in size by modifying MEXPATxx.OVR).  When the remote
stops (or the auxiliary buffer fills) MEX will write the ASCII-save buffer
to disk (if ASCII-save is active) and print characters until the printer
buffer is half-full (if List-copy is on).  Then MEX will re-start the remote
by sending an X-OFF character.

Note that for this scheme to work, the remote computer must respond to this
X-ON/X-OFF "protocol" (most computers do, but *not* all!).

You can transmit a local disk file to the remote with <ESC>-T; you will be
prompted for a filename.  If you have the XON and and XLINE variables turned
off (succeeding sections document these) MEX will ask if you want to use the
character and line delays for the filesend; these delays allow slow remote
computers to receive files.

The WCHAR and WLINE variables (see corresponding sections) determine the
time-delay values for each character, and each lines respectively (of course,
you must have answered "Y" to the "want delays?" prompt.

If either of the the XLINE or XON switches is ON, the delay prompt will be
skipped, and delays will not be used.

XLINE is a technique used by some mainframes: after a line is transmitted,
MEX will not transmit another until receiving an X-ON character from the
remote.

XON is more frequently used: when XON is active, MEX will send characters
at full speed, but monitor the remote for an X-OFF character.  When an X-OFF
is received, MEX will pause until the remote sends an X-ON character.

The APPEND secondary option:

MEX has a special feature that allows you to maintain 'log' files of your
sessions; this is the 'A' secondary option (specified with the T, E or L
primary commands when entering terminal mode IF a filename is specified).

When you specify the 'A' secondary option, MEX will search the logged area
(and/or the ALT area: see the ALT command description in section 7 for more
information on searching) for the file specified.  If found, MEX will scan
to the end of the file, and append new data on to the end, rather than
querying for an erase.

If 'A' is not specified, MEX will limit its search to the currently logged
DU, and, if the file is found, will ask you if it should erase the file.

In either case, if the file is NOT found, MEX will create a new file in
the currently logged DU.


5) Single-character commands

The most commonly used MEX commands are implemented as single character com-
mands, for ease of use.  These are:

S: Send a file or group of files using Christensen protocol
R: Receive a file or group of files using Christensen protocol
T: Enter terminal mode (may specify an optional ASCII-save file argument)
E: Enter terminal mode with echo (also takes optional filename argument)
L: Enter terminal mode with local-echo only (filename ok here too).

T, E, and L are all variations of terminal mode: T sends keyboard characters
to the remote and prints characters received from the remote on the console.
E mode echoes received characters back to the remote ("half duplex" mode), and
L echoes keyboard characters on the console before they go out to the remote
("half duplex" in the other direction).


6) Secondary commands (options)

The SECONDARY options are used only after the single-character commands,
and modify the way the single-character commands work.  Following is a
list of the secondary command options:

                        COMMANDS
OPT       NAME          USED WITH       ACTION
---     --------        ---------       ------
A       Append          E,L,T           Append to a terminal-mode file
B       Batch           R and S         BATCH mode, Christensenr file transfers
D       Disconnect      R and S         Disconnects after a file transfer
L       Local           T,E             Local-character echo
Q       Quiet           R and S         Sets "quiet mode" for file transfers
R       Recv-view       R and S         Shows received-characters only
S       Send-view       R and S         Shows transmitted characters only
T       Terminal-mode   R and S         Enter terminal mode after file xfer
V       View            R and S         Views the file transfer in ASCII
X       Exit            R and S         Disconnect and exit after transfer

Note that the options used with R and S are also effective with CIS transfers
(except for the 'B' option), if set with the GLOBAL command (see the command
description for "GLOBAL" in section 7).

Examples of secondary options:


Primary --+
Command   |+++-->secondary commands
          ||||
          |\ /
[MEX] A0>>ST   MYFILE.FOO       <<== send MYFILE.FOO, go into Term. mode after
[MEX] B9>>RVT  CRACKER.JAK      <<== receive file with view, enter Term mode
[MEX] A3>>RQX  MONKEY.SHN       <<== recv file quietly, disconnect/exit after
[MEX] A0>>RBT                   <<== recv batch files, Terminal mode after
[MEX] A0>>T    DISKFILE.SAV     <<== enter term. mode, allow save to disk file
                                (note that the actual copy to the file must be
                                activated with ESC-S while in terminal mode)
[MEX] B3>>TA   DISKFILE.SAV     <<== Enter tr area. The command


7) Command descriptions

Following is a list of the command set recognized by MEX.  In general, the
bracket characters denote optional items, and should not be entered literally.
For example, the syntax descriptor

        DIR [<du-spec>]

means that the du-spec is optional; hence, the command syntax may be satisfied
with any of the following actual command lines:

        DIR
        DIR A3:
        DIR 0:

Items surrouded in angle-brackets denote an item's type; the angle brackets
should not be included in the actual command line, nor should the description
inside the angle brackets be entered literally.  In the above example, the
descriptor <du-spec> is replaced with an actual drive/user specification.

--------------------

We will now look at each command in detail, in roughly alphabetical order.


- The ALT command

The ALT command specifies the ALTernate drive/user area to be searched
by MEX for LOAD files (.PHN and .KEY), READ files, and terminal capture
files (when APPEND is on).  Syntax is

        ALT <du-spec>

Examples:

        ALT A0:
        ALT B3:


- The BYE command

BYE is used to return to CP/M (does not disconnect) at the end of
a MEX session.


- The CALL command

The CALL command is used to dial numbers either from the library or from
the keyboard. If you specify more than one number on the command line,
CALL will try each until one answers with a carrier tone.  For example,

        CALL 16165559033 SENACA

will dial the first number; if busy (or no answer), CALL will try the second.
The special number '#' will cause the entire command line to be repeated if
none of the dialed numbers responds with a carrier:

        CAL WESTWOOD 1-616-555-2040 TCBBS #

will try all three numbers repeatedly until one answers.  You may op-
tionally place a limit on the number of retries by including a number
after the '#':

        CAL 555-1212 #48

A ^C will abort dialing at any time.

Phone-library numbers may specify an optional baud rate (see the description
for the PHONE command for information on how to specify the rate). If a
baud-rate is present, CALL will change the baud rate before dialing the number.

Note that, for this feature to work, your hardware must be capable of
changing the rate AND your overlay must implement the NEWBD vector.  Most
MEX overlays (overlays whose names start with "MXO-") allow this, if the
hardware is capable of baud-rate change; most MDM overlays do NOT.

- The CLONE command

The CLONE command allows you to save a new copy of MEX, with the current
options intact (including any defined keystrings and phone numbers). The
syntax is:

                CLONE <filename>

Examples:

        CLONE MEX.COM
        CLONE NEWMEX.COM

Clone will prompt you for an erase-file operation if the specified file al-
ready exists on the disk.

- The COLD command

The COLD command re-starts MEX and erases any defined keystrings along
with the phone library.  This is the only way to erase the entire phone
library with one command.  The COLD command also allows you to remove the
CIS protocol module (for those who don't need it) ... do this:

                STAT CIS OFF
                COLD
                CLONE <filename>

Note that this removes the CIS module altogether (you can't get it back
with the STAT CIS command).  This frees up roughly 1K of memory.


- The CPM command

CPM is a synonym for BYE, and returns control to the operating system
without disconnecting.

- The DEL command

DEL is used to close and erase an open terminal file; use this command
when you change your mind about saving a terminal file.

- The DIAL command


The DIAL command performs the same task as the CALL command, except that
after calling, DIAL returns to command mode (CALL goes to terminal mode).

The syntax for DIAL is exactly the same as the syntax for CALL (described
prevously), including the multiple-number feature and the repeat option.

DIAL is intended to be used in READ files, where it is desirable for the
READ file to retain control after calling a number (READ files have no
effect in terminal mode; thus using CALL in a READ file would pause ex-
ecution of the read file when the distant end is reached).


- The DIR command


DIR works similarly to the CP/M DIR command, and displays the disk directory
on the screen. DIR takes advantage of the DU specification, thus "DIR B7:"
will display all of the files in user 7 on drive B.  System files will be
excluded if the STAT variable 'EXCLUDE' is set to ON.  If EXCLUDE is OFF,
all files will be displayed.

More examples:

        DIR C3:*.?Q?
        DIR LOGIN.MEX
        DIR 3:

- The DSC command

DSC disconnects the modem from the phone line (may not be implemented
in all overlays).


- The ERA command

ERA erases files, similarly to CP/M's ERA.  The syntax is as follows:

                        ERA <filename> [V]

The filename may be ambiguous (e.g., *.ASM, BOOT?.BAK).  ERA always dis-
plays a list of the files that are being erased.  If you specify the
optional 'V' after the filename, ERA will ask for verification before
actually erasing the files (after displaying the names).

- The GLOBAL command

The GLOBAL command allows you to set the secondary options (described pre-
viously) for the single character commands.  Any options set this way will
then be active for the single-character commands whether or not they are
specified in the actual command line.  For example, if you prefer to go
directly to terminal mode after a file transfer, do:

                GLOBAL T

You can also set the VIEW mode for CIS transfers by doing

                GLOBAL V

(note that this is the only way to "view" a CIS file transfer.

- The EXIT command

EXIT is a synonym for BYE, and returns control to the operating system
without disconnecting.


- The HELP command

HELP is used to access the on-line manual for MEX (contained in the file
HELP.MEX).  Syntax for the HELP command is as follows:

    HELP            <<--- prints help for the HELP command
    HELP ?            <<--- lists available topics
    HELP <topicname>    <<--- prints help information for a topic

HELP.MEX must reside in the currently logged drive/user area (unless you
use an ALT area, with the SEARCH variable).  Once the help file is opened,
you may move freely among drive and user areas without affecting the op-
eration of HELP; MEX remembers where the HELP file is located.

Once opened, the HELP file will remain open for the duration of the
session, unless a LOG command is executed.


- The ID command

The ID command allows you to configure the MEX ID string (which is
printed in the prompt, and in error messages, if the STAT ERRID switch
is set to ON).  This is useful if you're communicating with another
computer running MEX; if each computer has a different ID string,
you're never in doubt as to which one you're typing commands to, or
which one printed an error message.

The syntax for the ID command is

                ID <string>               (see "STRINGS")

The string may be a multi-line string; it's length in the standard
distributed MEX may not exceed 28 characters.  This length may be different
if your system overlay replaces the MEX defaults (in fact, the overlay
may disable this command altogether; if the "INVALID COMMAND" message
appears when you attempt to use the ID command, then this is probably
the case.

-The KEY command

The KEY command is used to manipulate the keystrings that are available in
terminal mode.  There are several forms of the command:

        KEY                             <<= prints out all of the keystrings
        KEY <keyname>=[<string>]        <<= defines a new keystring

Keyname is any valid ASCII character, except for the set defined as the
terminal mode escape-sequence commands (see TERMINAL MODE).

In the second form, above, if <string> is omitted, then the specified key-
string is erased.

Examples:

        KEY %="ATDT 14145559932"        <<= sets up the '%' key
        KEY Q=                          <<= erases the Q keystring

Note that KEY names that duplicate terminal-mode commands will be rejected
by the KEY command, and an error message will be printed.


- The LOAD and SAVE commands


LOAD and SAVE are used to load and save phone number and keystring files.
Both commands take a filename argument.  Examples:

        LOAD A5:CBBSPHON.PHN            <<== loads a phone # file
        LOAD ARPA.KEY                   <<== loads a keystring file
        SAVE C:NEWPHONE.NUM             <<== saves phone # file
        SAVE 9:COMPUSRV.KEY             <<== saves keystring file

Note that the filetype determines what type of file is being saved (.PHN
for phone number files, .KEY for keystring files).  Any other filetype
will generate an argment error.

- The LOG command

The LOG command allows you to reset the drive (for switching disks) and,
optionally, simultaneously change drive and/or user area. The command
syntax is

                LOG <DU-SPEC>

where DU-SPEC is either or both of the new drive to log into and the new
user area.  An optional colon may follow the DU-SPEC.  Examples:

                LOG B7:         <<= reset, log in drive B user 7
                LOG 7:          <<= reset, log user 7 current drive
                LOG B:          <<= reset, log drive B current user
                LOG             <<= reset, retain current user/drive

If either a terminal file or a READ file is open, the disk-reset will be
denied and the LOG command will display an error message.

If you want to change drive and/or user without a disk reset, you can do so
without the LOG command: just enter the DU spec at the MEX command prompt.


- The PHONE command

The PHONE command may be used to query the phone number library, as well as
for adding and deleting numbers.  To add a number, use this form:

                PHONE <id>=<number> [baud-rate]

Where ID is a string (up to 8 characters) that you want to use to call out
the number and <number> is the telephone number.  If <id> already exists,
it will be replaced.  <Baud-rate> is an optional rate to be associated with
the number, used by the CALL command.  To remove a number, do

                PHONE <ID>=

To see the entire library, do

                PHONE

To see a single entry, do

                PHONE <ID>

Examples:

  PHONE FORTFONE=1-414-563-4013 1200    <<--- associates number w/FORTFONE
  PHONE FORTFONE=1-414-563-4013         <<--- same but doesn't change baudrate
  PHONE                    <<--- lists the phone number library
  PHONE FORTFONE=            <<--- removes FORTFONE from library
  PHONE FORTFONE            <<--- prints entry for FORTFONE

- The PREFIX and SUFFIX commands


PREFIX and SUFFIX are used with the SENDOUT command (described later). PREFIX
is used to manipulate a special PREFIX string, and SUFFIX is used to manipulate
a SUFFIX string.

The PREFIX string is transmitted ahead of any SENDOUT string, when the
SENDOUT command is used, and the SUFFIX string is transmitted after.  This
simplifies the construction of complex, repetitive command lines to be sent
to the remote.

Either command without arguments prints the current value of the string. To
change the string, enter the string on the command line after the command.

Examples:

                PREFIX ""               <<== sets null prefix string
                PREFIX "XMODEM S "      <<== sets a prefix
                SUFFIX "^M"             <<== set carriage-return as suffix

In the second and third examples above, the subsequent SENDOUT would work
like this:

        SENDOUT FOO.BAR

which would actually send out   "XMODEM S FOO.BAR" <carriage-return>.


- The READ command

The READ command causes MEX to take command lines from a disk file. This
can be handy for such things as controlling a set of file transfers (es-
pecially when you can't be present for the entire session) and executing
complicated login sequences automatically. READ, used with the EXTEND
function (see the description of the EXTEND variable in section 8) provides
a means of extending MEX's command set.

The syntax for READ is:

        READ <filename> [<parm1>] [<parm2>] ...
                            \          \
                              \ ________\_____>> optional!


The READ file may contain any valid command EXCEPT another READ command.
These commands may freely move among drives and user areas; MEX will re-
member where the READ file is located.

Typically, READ files are created with a text editor, and may contain
STAT commands to set MEX for a particular type of connection, DIAL commands
to actually make the connection, and SENDOUT commands to log in at the
destination.  It's possible for an entire session to take place under
a READ command.

A READ file will terminate when the file ends, or when a CONTROL-C is
seen at the console (aborting any command with CONTROL-C will abort the
READ file).

It's important to note that, while you can use a READ file to enter the
terminal mode, the READ file is not used while the terminal mode is active.
When you exit terminal mode, the READ file starts again.

Normally, READ commands echo on the screen when they execute. You
can inhibit this, however, by manipulating the SILENT variable (do
STAT SILENT ON to inhibit the command echo).

READ parameters are very similar to CPM's SUBMIT parameters; they are called
ACTUAL parameters. If they are present in the command line, they will be
plugged into the FORMAL parameters in the submit file.  This substitution fa-
cility provides a powerful tool for generating multiple-purpose command files.

Formal parameters occur in the READ file, and take the form {n}, where n
is the parameter number; these numbers correspond sequentially with the
ACTUAL parameters entered on the command line.  The ACTUAL parameters in
the command line are substituted for the FORMAL parameters in the READ file
when the file is executed.  A special form of FORMAL parameter allows a
default value to be used if an ACTUAL parameter is not specified on the
command line; this form is {n:<text>} where n is the parameter number, and
<text> is any arbitrary text to be used as the default.

If the default form of the formal parameter is not used, AND no actual
parameter is specified in the command line, execution will continue, but
the parameter will be blank.

Normally, the parameters in the READ command line are terminated by the
space between parameters (or the end-of-line); spaces can be imbedded in
the ACTUAL parameter by enclosing it in braces.

I know this all sounds quite complex, but it's really quite simple, as
the following example will show.

Assume a file named FILEGET.MEX contains the following lines:

SENDOUT XMODEM S{2} {1:SENACA.DQR}
R{2} {1:SENECA.DQR}

( {2} and {1:SENACA.DQR} are FORMAL parameters). This file can be used in
several ways:

        READ FILEGET            will simply transfer SENACA.DQR to your system
        READ FILEGET MEX.UPD    will transfer MEX.UPD to your system
        READ FILEGET *.NEW B    will transfer all NEW files in batch mode
        READ FILEGET USQ.DOC VT will transfer FILEGET, View it, goto Term mode

The following line illustrates how to expand a parameter, using the above file,
and is useful only if MEX is running on the remote end:

        READ FILEGET {*.BOO NEWSTUFF.DOC} BX

(Transfers all .BOO files and NEWSTUFF.DOC) in batch mode, then disconnects)

If you turn the command extender on (STAT EXTEND ON), the READ in the above
lines can be omitted, making the READ file look like a built-in command. This
affects single-character commands somewhat: the disk is searched before the
the command is checked for a single; you can avoid this by prefixing single-
character command lines with a '*'  (eg, *RQ FILE.FOO).


- The REN command

The REN command  syntax is similar to the CP/M's REN, except that DU spec-
ifications may be employed in either the new OR the old filename (but not
in both).

In general the syntax is

                REN <newfilename>=<oldfilename>
 Examples:
                [MEX] A0>> REN NEWFILE=OLDFILE          (uses A0)
                [MEX] C9>> REN B6:REPORT.OLD=REPORT.DOC (uses B6)
                [MEX] B4>> REN 6:MYFILE=B:YOURFILE      (uses B6)
                [MEX] D4>> REN ERROR=C9:BLUNDER         (uses C9)

Note that the following REN commands will produce errors:

                [MEX] A0>> REN B3:SOMETHING=C:ELSE      (ambig drives)
                [MEX] A0>> REN 6:ME=7:YOU               (ambig user #'s)

Note that ERA will prompt for erasure if the new name already exists.  Further,
before doing this, it checks for the existance of the old filename, and, if
not found, aborts before checking for the the presence of the new name.


- The SENDOUT command

SENDOUT allows you to send an arbitrary string out to the modem (see STRINGS).
This is most useful in READ command files, but can often be useful in normal
interactive mode.

The syntax for SENDOUT is

                SENDOUT <string>

Before the specified string is transmitted, a PREFIX string, if any,
is transmitted, followed by the string specified to SENDOUT, and
terminated by a SUFFIX string  (if any; the default suffix string
is a return-code, normally terminating the line to the remote). After
transmitting the string, MEX will wait for a reply from the remote, up
to a pre-set number of seconds; any reply will printed on your screen.

Following are settings and variables which affect the SENDOUT command:

SUFFIX: \  Described previously
PREFIX: /

WTECHO: Manipulated by the STAT command, this switch-variable determines
        whether or not SENDOUT validates its transmission by waiting for
        characters to be echoed from the remote.  If set to ON, then
        SENDOUT checks each printing character it transmits with the
        character as echoed by the remote.  If a mismatch occurs, SENDOUT
        marks an error, sends a CANCEL character, and awaits a TRIGGER
        character from the remote.  It then begins again, and repeats
        this cycle until either the transmission occurs without error,
        or the error count is exceeded (which aborts SENDOUT).

        If you use SENDOUT with WTECHO off, you'll also likely want to
        set TRIGGER to null (STAT TRIGGER ""), to avoid trigger-wait.

More factors affecting SENDOUT:

RETRY   Manipulated by the STAT command, this value-variable specifies
        the error-retry count for SENDOUT before aborting.

CANCHR: Manipulated by the STAT command, this string-variable (single
        character) specifies the character to be transmitted to the
        remote to cancel the transmitted line after an error.

TRIGGER:Manipulated by the STAT command, this string-variable (single
        character) is the character the SENDOUT command waits for after
        an error-cancel, before proceeding with the retry. If the other
        end doesn't echo, set TRIGGER to 0 (and WTECHO to OFF), and MEX
        will simply send its arguments and not worry about validating
        the echoed string (this is the technique you should use to send
        Smartmodem command strings, for example).


- The SET command

SET is a command defined entirely by the overlay; if your overlay doesn't
implement the SET command, MEX will print the "invalid command" message
when you try to invoke SET.


- The SLEEP command

SLEEP is used to invoke a delay (handy sometimes in READ files).
Syntax is:

                        SLEEP n

where n is the number of seconds to wait (a ^C from the console
will abort the SLEEP command, as well as any active READ file).

Sleep, used with the STAT CLOCK function, can be used to "tweak" the
timing constants in MEX (by timing the actual SLEEP period, and ad-
justing the CLOCK value until the SLEEP argument agrees with the actual
measured time).  This is especially useful with multi-tasking operating
systems, such as MP/M and TurboDOS, where background processing wreaks
havoc with the internal MEX timing constants.

- The STAT command

The STAT command lets you examine certain system variables, and change
certain others.  In general, the syntax is as follows:

        STAT <KEYWORD>              <<== to examine a variable
        STAT <KEYWORD> <NEW-VALUE>  <<== to change a variable

The NEW-VALUE will depend on the context of the keyword in question. For
example, most of the switch-type variables are either ON or OFF, hence,

        STAT BAKFIL                 <<== prints out ON or OFF
        STAT BAKFIL ON              <<== turns on BAKFIL
        STAT BAKFIL OFF             <<== turns off BAKFIL

The value-type variables, on the other hand, will print the number or
text associated with that variable.  Setting the value requires the entry
in units associated with that value.  For example,

 STAT REPLY 5               <== sets 5 seconds as SENDOUT reply time
 STAT WCHAR 4               <== set 40 ms as transmit-character delay tim
                                during a terminal-mode file send

Some variables are read-only, most notably STAT BUFFER (which prints
out the save-buffer and printer-buffer statistics).

To obtain a list of all of the options that can be viewed or changed with
the STAT command, do

        STAT ?

Most of the STAT keywords are documented in section 8.


- The TYPE command

The TYPE command prints files on the console, similarly to the CP/M
TYPE command, but with pagination:  The syntax is:

                TYPE <filename> <'P'>

The optional 'P' will affect pagination at screen boundaries: if pagination
is OFF ("STAT PAGE OFF") then 'P' will cause the file to be paged.  If
pagination is ON ("STAT PAGE ON"), then 'P' will inhibit pagination.


Examples:

                A2>>COMMAND: TYPE REPORT.DOC    (paged output if PAGE ON)
                A2>>COMMAND: TYPE REPORT.DOC P  (inhibits paging if PAGE ON)


- The SYSTEM command

SYSTEM is a synonym for BYE, and returns control to the operating system
without disconnecting the modem.

- The WRT command

WRT is used to close and save an open terminal file. An automatic WRT
if performed for you if you use any of the exit commands (BYE, EXIT,
CPM, or SYSTEM) while a terminal-mode file is open.

-----------------------

8) STAT variables

This section describes the variables that may be examined or changed
with the STAT command.


- The ALERT variable


ALERT is a STAT value variable; it determines the number of times the
console bell will ring when a remote computer is reached with the CALL
and DIAL commands.  ALERT works only on calls that have taken more than
one dialing attempt to reach.

ALERT is handy for dialing with the repeat option (see CALL command in
section 7 for more information about the repeat option): you can enter a
number (or group of numbers) to be dialed; with ALERT set non-zero, you'll
have an audible signal that a call has been completed.


- The BAKFILE variable

BAKFILE is a STAT  Switch variable: if ON, any command that creates a file
when one of the same name already exists will, instead of erasing the old
(or prompting for an erasure) rename the old with the same primary name,
and a secondary name of "BAK".


- The BELL variable

BELL enables or disables the console bell througout MEX (ie, in terminal
mode, command mode, and during file transfers).


- The BUFFER variable

BUFFER is not really a variable; use STAT BUFFER to print out the ASCII
capture buffer statistics (size, amount used, amount available).  In ad-
dition, STAT BUFFER displays the batch-filenames buffer size (which de-
termines the largest number of files that my be transferred in one batch
file transfer command).


- The TRIGGER and CANCEL variables

TRIGGER is a STAT CHARacter variable, and specifies the character the SENDOUT
command will look for before sending out its argument (a single-character
prompt from the remote).  To disable the trigger-wait function altogether, do

        STAT TRIGGER ""

CANCEL is anoter CHAR variable, and specifies the character the SENDOUT command
will send to the remote to cancel the line after an error.


- The CHAR variable


CHAR is not really a varible, but a command option to STAT that prints a list
of all of the CHAR variables.


- The CHECKSUM and CRC variables

CRC and CHECKSUM are switch variables; the two are mutually exclusive (that
is, turning one on turns the other off) and set the preferred type of error
checking in Christensen file transfers.

CHECKSUM is a simple sum of the outgoing record; CRC uses a more sophisticated
technique employing polynomial arithmetic, and is thus a better method (more
errors are detected, thus, there is less chance of an incorrect record being
received as if it were valid).

The original MODEM2 protocol employed only CHECKSUM detection; however, in
the past few years, most versions of Christensen exchange programs have been
rewritten to accept the CRC technique as well.  MEX will adapt to transmitting
programs using either type of validation.

If MEX is the transmitter, it will switch modes after several failed attempts
to transmit a file, thus allowing full compatibility with older modem programs.


- The CIS variable

CIS is a STAT switch: when ON, then Compuserve protcol file transfers
are allowed while in terminal mode.  If OFF, Compuserve transfer sequences
from the remote end are ignored altogether (although they are printed on
the screen as "normal" terminal-mode characters).

CIS transfers always take place while in terminal mode; there is no command to
send or receive a file using CIS protocol, since the remote Compuserve end
must initiate the transfer.

Note that if you use the COLD command to restart MEX while the CIS switch
is set to OFF, then the Compuserve file transfer module will be removed
altogether from the running copy of MEX.  If you subsequently use the CLONE
command to create a new executable MEX.COM, the additional space formerly
used by the CIS module (about 1000 bytes) will be available instead for
your buffers.  You will not be able to use STAT to turn the CIS switch back
on (since there is no longer a CIS module in the system).  This feature is
intended for those users who do not need the ability to do Compuserve-
protocol transfers, and would rather not waste space on an unneeded feature.


- The CLOCK variable

CLOCK is a STAT value variable; you may set this variable to any value be-
tween 1 and 255.  The value is the CPU clock speed in tens of Megahertz
(hence, the speed may vary between .1 and 25.5 Mhz).  You can then use
the CLONE command to make this change permanent.

CLOCK is useful for "tweaking" MEX under varying conditions of load when
running under multi-tasking operating systems, such as MP/M and TurboDOS.
When system load is heavy, you can decrease the CLOCK value, causing MEX
to spend less time in its internal timing loops.


- The DEBUG variable

DEBUG is a STAT switch that affects the Terminal mode in MEX.  If DEBUG
is ON, then characters received in Terminal mode are displayed in a form
similar to CP/M's DDT dump (D) command: hex values on the left side of
the screen and the ASCII block (as the output progresses) on the right.

You'll note that the ASCII right-side display is "buffered" until 16
characters have been received.  After the 16th, the ASCII right-side
is printed.  Therefore, if the remote's output pauses, you'll see only
the hex values until the remote sends more output.  Also, exiting Terminal
mode will display any buffered ASCII.

DEBUG is useful whenever it's necessary to know exactly what the remote
is sending (for example, if you're connected to a time-share network, and
can't transfer files, a DEBUG session can prove illuminating in determining
just what is happening).

In DEBUG mode, the FILTER flag is ignored, allowing all characters to
reach the screen.  Additionally, the CIS protocol is disabled while DEBUG
is ON.


- The HEX and DECIMAL variables


HEX and DECIMAL are STAT switch variables; they are mutually exclusive (ie,
turning one ON turns the other OFF.  These variables specify the default
input radix of commands that take numeric arguments (e.g., SLEEP, STAT VAL
<#>, the '#' spec in CALL commands, etc).  If HEX mode is ON, then these
numbers are considered Hexadecimal; if DECIMAL mode is on (MEX is distributed
with DECIMAL ON), then they are considered decimal values.

You can force a decimal number, regardless of the HEX or DECIMAL mode, by
preceeding the number with a '$' character; similarly, the '#' character
implies a decimal number.

HEX mode has a side effect: it turns on HEX record count reporting in file
transfers.


- The ERRID variable

ERRID is a STAT switch that enables and disables the printing of the MEX
ID string in error messages.

The ID string is useful in applications where you're communicating with
a remote computer running MEX (if each end has a different ID code, there
is no problem confusing error messages), but if you typically use MEX
only with RCPM systems or timesharing systems that don't run MEX, you'll
likely want to turn off the ERRID switch, and shorten the error messages.


- The EXCLUDE variable

EXCLUDE is a STAT switch-type variable.  It modifies the action of commands
that take multiple-filename arguments (such as DIR and the batch-transmit
SB).

If EXCLUDE is ON, then SYS files are skipped over by these commands.

If EXCLUDE is OFF, then SYS files are included.

Thus, you can exclude SYS files from a batchfile transmission by STATting
the EXCLUDE switch ON.  These files will also be exclude from DIR listings
while EXCLUDE is ON.


- The EXTEND variable

EXTEND is a STAT switch variable.  When turned on, it modifies the way
MEX's command decoding works: if a command is not found in MEX's command
table, MEX will pass the entire command line on to READ, causing the
command to look like a READ command (without READ being present on the
command line).

For more information, see the description of the READ command in section 7.


- The ESC variable

ESC is a STAT CHAR variable, and specifies your terminal-mode escape character,
used to activate terminal-mode functions (such as capture and printer buffer
on/off, etc). The argument is a single character string.  Example:

                        STAT ESC "^I"

     changes your escape character to the TAB key.


- The FILTER variable

FILTER is a STAT switch variable; when ON, then abnormal control characters
are ignored when in terminal mode (with the exception of carriage-return,
linefeed, backspace and tab).  If OFF, then all characters from the remote
will be displayed on the screen (and included in the ASCII-capture file,
if active).

FILTER ON is useful if you're working with a noisy connection, and random
garbage characters on the line are erasing your screen, etc.

If you're using a video-oriented text editor at the remote, you'll need to
be sure FILTER is set to OFF, in order to allow the video-control characters
to be accepted by MEX.

Note that the CP/M end-of-file mark is specifically excluded from ASCII-
capture files regardless of the setting of FILTER (although FILTER ON
allows this character to go to the screen).


- The INITFILE variable

INITFILE is a STAT switch variable.  It determines whether or not MEX
will look for the start-up file INI.MEX when it is first started.

INITFILE is intended to be used prior to running CLONE, to prevent the
cloned MEX from looking for INI.MEX.

For more information about the CLONE command, see its command description
in section 7.



- The LF variable

LF is a switch variable: if ON, it affects terminal-mode file transmission by
adding a linefeed after every carriage return.


- The LIST variable

LIST is a Switch variable, and enables or disables the LIST device.

- The PAGE variable

PAGE is a STAT switch variable: if on, the TYPE command paginates;
TYPE scrolls if PAGE is OFF.


- The REPLY variable

REPLY is a STAT value variable, and specifies the amount of time (in seconds)
that the SENDOUT command will wait, after sending a string, for the remote end
to send a reply. Any such reply will be displayed on your terminal screen.

To query the REPLY constant, do: STAT REPLY

To set the REPLY time, do:       STAT REPLY <value>

where <value> is the number of seconds to wait, between 0 and 255.


- The RETRY variable

RETRY is a STAT keyword, and specifies the number of times the SENDOUT
will attempt to send a string before aborting.  Note that if the Wait-For-
Echo switch (WTECHO) is off, RETRY will have no effect, since no error
can occur.

To query the RETRY constant, do: STAT RETRY

To set the RETRY constant, do:   STAT RETRY <value>

where <value> is the number of retries, between 1 and 255.


- The RTIME varible

RTIME is a STAT value variable, and affects Christensen-protocol file
transfers.

RTIME is the amount of time (in seconds) that MEX will wait for a char-
acter from the remote end before declaring a timeout, and initiating
a record-retransmission sequence.

RTIME is set for one second in the standard distribution MEX; this is
more than adequate for RCPM work, and MEX-to-MEX file transfers where
each end is running under a single user operating system.  But when
working with a mainframe-type connection (and sometimes when a remote
MEX is running under MP/M), especially when a packet-switched network
is part of the connection, character delays can easily exceed one second.
In these environments, you'll want to set RTIME to a higher value (16
seconds is recommended; the maximum is 30).

- The RUB variable

RUB is a STAT switch variable and affects terminal mode: if ON, then the
local backspace key is converted to RUB when the character is transmitted
to the remote.

- The SEARCH varible

SEARCH is a STAT variable that may take on the values 0, 1, 2 or 3.  SEARCH
specifies a search path for READ files, phone libraries, keystring files, and
(if the append secondary option, 'A' is specified) terminal-mode ASCII capture
files.  These files normally are taken only from the currently logged DU; by
modifying SEARCH, you can change the way MEX finds these files.

Two drive/user areas are possible: the currently logged area ("logged" D/U)
and the Alternate DU (do HELP ALT for information on changing the alternate).

If SEARCH=0, then only the LOGGED DU is searched.
If SEARCH=1, then only the ALT DU is searched.
If SEARCH=2, then the LOGGED DU is searched; if the file is not found, then
             the ALT DU is searched.
If SEARCH=3, then the ALT DU is searched; if the file is not found, then the
             LOGGED DU is searched.


- The SWITCH variable

SPLIT is a STAT switch variable that affects the screen display of the phone
library (done from the PHONE command or the CALL command).

Normally the phone library is printed two numbers per line, to effect a
compact display with as much information as possible.  This compact display
does not, however, provide enough room to include the number's optional
baud-rate.

By setting SPLIT to ON, numbers will be printed one per line, and each
number's baud rate (if present) will be displayed.


- The SILENT variable

SILENT is a STAT switch variable, and, when ON, inhibits the echo of command
lines in READ files.


- The SWITCH variable

SWITCH is not really a varible; it requests the STAT command to list out all
of the switch-type variable.

- The VAL variable

VAL in not really a variable; it requests the STAT command to list out all
of the value-type variables.


- The WCHAR and WLINE variables

WCHAR and WLINE  are value variables; they specify delay times in simple
file transmissions done within terminal mode (with the <ESC> T command). When
you transfer a file, MEX will ask you whether you want to use these delays.

WCHAR is the delay to use between characters.(0-9, in 10's of milliseconds)
WLINE is the delay to use between lines      (0-9, in 100's of milliseconds)

WCHAR and WLINE delays are often needed for timesharing mainframes and
BBS's written in BASIC, to allow the slower remote end to catch the entire
file.


- The WTECHO variable

WTECHO is a STAT switch variable, and determines whether or not keystrings
and SENDOUT command lines transmitted to the remote are validated by compar-
ison with their echoed characters.

When WTECHO is ON, all printing characters transmitted to the remote
must echo correctly back from the host; this effectively halves the
transmission rate, but provides error correction feedback for the SENDOUT
command, allowing it to cancel a line and re-try.

If you're sending command strings out to a line that doesn't echo the
characters, you'll want to set WTECHO off.  Additionally, if you're using
the SENDOUT facility, you'll need to remove the trigger string (you can
do this with STAT TRIGGER "" , which effectively removes the trigger
character.


- The SEP variable

SEP is a STAT CHARacter variable, and allows you to change the command-line
separator character. The argument is a single character string. Example:

                        STAT SEP "$"

changes your command separator to the "$" character.


- The XLINE variable

XLINE is a STAT switch that affects terminal-mode file transfers.  If
XLINE is set to ON, then the file will be transmitted, one line at a
time; each succeeding line will not be transmitted until an X-ON character
is received from the remote.

XLINE is used with some timeshare and network computers, almost never
with RCPM and BBS systems.


- The XON variable

XON is a STAT switch variable that affects the terminal-mode file send
(see TERMINAL MODE for a full description of terminal-mode file send).

When XON is set to ON, MEX will send all characters to the remote at full
speed, but will monitor for an X-OFF character from the remote.  When
MEX sees the X-OFF, it will pause, allowing the remote to read all of the
input MEX has transmitted.  When MEX sees an X-ON character from the remote,
it will resume the file transmission.

--------------------------

9) About the source code (and other stuff).

Some users will note that MEX is distributed without source code; this is
not an oversight.  MEX occupied a substantial amount of my spare time over the
last few months, and I've become very possessive of the program (especially
in light of what's happened with so many other programs appearing in source
form on various RCPM's and through user groups -- they tend to get modified to
death by people who do not properly consider the effects of their changes).
For this reason, I will not be releasing source code for MEX in any form, bey-
ond the source for the overlay files..

I do intend to maintain the program as responsibly as is possible for any
non-funded project.  In addition, a number of enhancements are planned for
later this summer, to culminate in a 2.0 release that will offer significant
enhancements (including a simpler overlay structure, a far-more powerful
READ command processor, including nested reads and conditional execution,
smart-terminal emulation, and the capability of MEX to act as a remote-
terminal server, similar to the public domain BYE program).  I cannot guar-
antee, however, that MEX 2.0 will be distributed without charge (as MEX 1.0
is); if I decide to sell MEX 2.0, you can be assured that it will be one of
the cheapest terminal programs available for CP/M and as well supported as
any commercial product available.


10) Support

MEX has been beta-tested among a small group over the last few months; however,
the nature of software development implies the existance of a microscopic
fissure through which program bugs will invariably ooze, escaping detection
by all but the omnipotent (I am, sadly, not among that group).

So if you detect errors or bugs in MEX, I would like to know about it. You
can reach me through the following avenues:

    Arpanet:    send mail to [e-mail]
    Compuserve: send mail to Al Jewer (70040,321)
    RCPM:        If you're a sysop, leave me a message on the Dearborn,
            MI, Sysop RCPM.  Otherwise, leave a message on Keith
            Petersen's RCPM: [phone].  After June 1, our
            local RCPM should be back "on-the-air": Fort Fone File
            Folder, [phone].  This will be the best way to
            reach me after June 1.
    US Mail:    My mailing address is Route 1, Box 7, Fort Atkinson, WI;
             be aware that I am very slothful about answering non-
            electronic mail (ie, you may never get an answer).
    Telephone:  None.  Please do *not* call me at home; this raises
            hell with my family, and I'm not normally able to re-
            spond in "real-time" in any case. (This does not ap-
            ply, of course, to any of my paying customers who may
            be reading this).

If you report a bug, please be as explicit as possible, detailing any unusual
overlay configurations, STAT variables, and any other conditions you feel are
pertinent.  Bug reports like

        "Terminal mode doesn't work right"

are totally useless; all I can do is ignore such reports.

Feature requests for future releases of MEX are welcomed.

11) Credits

I'd like to thank the following individuals for their participation in the
development of MEX, which included many suggestions for features, beta-
site testing and helpful feedback (and, in the cases of Bob Plouff and
Frank Wancho, code examples from their own communicatons programs):

Bob Plouffe     Dick Mead     Keith Petersen     Al Jewer
Frank Wancho    Sigi Kluger   David Sternlight   Shawn Everson
Dave Kozinn     Charlie Strom Eric Stork


Special thanks must go here also to Ward Christensen, who wrote the original
MODEM program from which all others have descended, Mark Zeiger, who dev-
eloped the batch-file transfer protocol extension to Ward's original MODEM2
protocol, Irv Hoff, whose work with MDM7 provided a foundation for a common
overlay format between MEX and MDM7, and the dozens of others who have con-
tributed to the development of the many versions of MODEM2, MODEM7 and MDM
(from which MEX began with a healthy advance along the learning curve).

11) Distribution and a warning to illicit profit-takers

MEX and its documentation are Copyright (C) 1984 by Ronald G. Fowler.  A
license is extended to users to copy and exchange the program and documentation
with the sole restriction that such distribution must be non-commerical in
nature (this is not to imply that charges for such things as diskettes and
modest copying and mailing fees are of themselves commercial in nature). Re-
sale for profit may be done only with the express written consent of the
author, Ronald G. Fowler.

The US Copyright Act of 1978 provides for severe penalties for infringement,
including actual and punitive damages on a per-occurance basis.  The value I
attach to MEX is in circulation of my name as a consultant and contract pro-
grammer; this circulation-of-name will be used as a basis for actual damages
in any infringement suit.

Legitimate commercial interests interested in custom versions of MEX, for
distribution as a for-profit product, should contact the author for rates,
royalty information and sample contracts.

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                    Ronald G. Fowler
                    Fort Atkinsone, WI   53538
                    May 7, 1984