COMD is a program which lets you share serial devices such as modems
over a network.  Eventually COMD may include features specify to
devices like dialing HAYESMODEMSs and passwords.  Methods for
configuring such features have been listed, but are not implemented
and will bring unpredictable results.

Possible uses for COMD include :
  o  remote connection to serial printers - unlike pc's running LPD, COMD
     allows the host to perform accounting and eliminates the need for
     a local hard disk on the pc

  o  can be easily modified to function as a dial out modem pool

  o  could be modified to works as a dial out fax modem pool

  o  can be used to let a remote host control lab equipment or
     collect data from remote sources

To use COMD you will need a valid WATTCP.CFG file.  Documentation on
the general WATTCP programs provides that information and you are
referred there for more details.  Once PING and FINGER work, you may
proceed on to the next paragraph.

For each serial device you must add several lines to your WATTCP.CFG
file.  You must specify the following:

COM.PORT = 1 | 2 | 3 | 4
	You will receive an error message on bootup if one of the specified
	ports does not exist.
COM.PARITY = EVEN | ODD | NONE | MARK | SPACE
COM.BITS = 5 | 6 | 7 | 8
COM.STOP = 1 | 2
COM.TCPPORT = some port number, 23 is TELNET
COM.MODE = RS232 | TEST | HAYESMODEM
        To test a new device, use the TEST mode which will let you
        interactively 'talk' with the serial device.
        The HAYESMODEM mode is not implemented yet.
COM.HANDSHAKE = XON | MODEM
COM.DELAY = xxx
        xxx is minimum delay between transmissions in 10ths of a second.
        It is used to collect a reasonable amount of data before sending it
        over the network.  A value of 0 is very greedy, 2 is very reasonable
        for terminal servers or modems, 10 is fine for laser printers.

For example, to configure COM1 and COM2 you may use:
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
com.port=1              # simple modem
com.mode=RS232          # vs. TEST (or HAYESMODEM)
com.tcpport=23          # TELNET port
com.handshake=XON       # vs. MODEM
com.delay=2             # in 1/10s of second pick 0 - 2, 0 is costly
com.baud=9600
com.parity=none
com.bits=8
com.stop=1

com.port=2              # RS232 based printer
com.mode=RS232
com.tcpport=800         # user defined port
com.handshake=XON
com.delay=2             # in 1/10s of second pick 0 - 2, 0 is costly
com.baud=9600
com.parity=none
com.bits=7
com.stop=1
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

Up to four devices may be used similtaneously, but you should have a
machine fast enough to handle those serial interrupts.

You can do load leveling, where two devices are assigned to the same
tcp port.  That way, if one is busy, the other will be used.  All
you have to do is specify the *same* com.tcpport number for both
and the software manages the rest.

The com.delay value is the amount of time (in 100 millisecond quantities)
during which COMD accepts characters from the RS232 port before it
transmits the over the network.  This produces a slight delay, but
it reduces packets dramatically.  For highly interactive sessions,
1 to 2 is reasonable.  For others, 5 to 10 gives a delay between
a half second and a full second.

If you add new features to COMD, please send them back to me so others
can benefit from your time and expertise.


                     **** IMPORTANT NOTES ****

Many people have their Ethernet cards set to irq 3 (interrupt level 3).
In fact, that's how the cards usually arrive from the factory.
Unfortunately irq 3 is also used by COM2 and COM4, and gives rise to
a conflict.  I didn't write the com libraries, I don't even have source
for them, so I can't fix it.  You can solve the problem by moving the
card to a different interrupt.

If you intend to use COMD, you should remember that the com port libraries
(Litecomm) are copyrighted by Information Technology Ltd. and should be
registerred with that company.  I have no affiliation with ITL, I just
downloaded these files from simtel and found they suited the task very
nicely.

