Short:        Let's you write Modem Linkable games easier (Oct 13 1997)
Author:       yogi@autobahn.mb.ca (Michael Veroukis)
Uploader:     yogi autobahn mb ca (Michael Veroukis)
Type:         dev/misc
Version:      36.2 Release 1.2
Requires:     Amiga OS 2.0 or higher
Architecture: m68k-amigaos


                               ModemLink Device
                             Mike Veroukis - 1997

Introduction:
~~~~~~~~~~~~

  The ModemLink device was written in an attempt to make modem linkable
games easier to write on the Amiga.  We've seen hundreds of games on the
PC with modem play capabilities, but most Amiga games don't provide this
option.  This frustrates many Amiga game players, as everyone knows it's
much more fun to kill your friends then stupid computer-AI people!

  It's no secret that most Amiga programmers are not part of some rich
company.  Therefore, it's easy to understand why many developers don't add
modem play to their games.

  First of all, you may be adding a few months to development time just for
the modem link part of the game.  For many hobby programmers, they'd rather
just finish the game quickly, and move onto new and exciting things.  The
ModemLink device gives the developer all the code required for a basic
modem playable game, therefore saving on development time.

  Another problem is that you'd need two Amigas, with a modem on each, and
preferably two phone lines (although you could always use a null modem as
well).  Not everyone can have this kind of set up.  The ModemLink device
makes it a little easier to develope the modem linkable game, since there's
less to worry about.  You'll still need to test, but it's the sort of thing
a friend with an Amiga and a modem can help out with.  Since the ModemLink
device has been tested, and is known to work, a game developer only needs to
worry about how to interface with the ModemLink device.

  Well, this is all very cool and all, but how does it work???  Although I
don't want to get into the finer details of the device, this is a good
place to give a rough description of the thing.

  The ModemLink device provides two important functions;  Modem Connectivity
and a Reliable Serial Protocol.  What does this mean???

  Modem Connectivity:
  ~~~~~~~~~~~~~~~~~~

  The ModemLink device provides standard routines to dial/answer calls.
These routines can be used to easily set up a modem connection.  They have
been designed to be very flexible and provide significant control to the
programmer.

  Reliable Serial Protocol:
  ~~~~~~~~~~~~~~~~~~~~~~~~

  Once a modem connection is made, data must be sent and received across the
phone line.  One needs to be sure that the data received is correct, and
the data sent has been received.  To do this, some kind of protocol must
be used, which the ModemLink device provides.  Although designed to support
more protocols in the future, it currently only supports a single protocol
based on what is called the Stop And Wait protocol.

  Anyway, as you might have guessed, the main point to this entire project
is to make it easier for Amiga programmers to make modem linkable games.  I
offer this package (with source included) free for everyone to use.


Release History:
~~~~~~~~~~~~~~~

R1.2 V36.2 (Oct 26 1997):
     - ModemLink.device would not create the ModemLink Semaphore which is needed
       to make sure that only one instance of modemlink.device is running for a
       given Unit.  This has been fixed.


R1.1 V36.1 (Oct 25 1997):
     - SendModemCMD now checks to see if modem is OFF only if issued command is
       never echoed back from modem.  This is to be compatible with newer
       modems which auto power-up when first command is issued.
     - Cleaned up some documentation.
     - Changed the scoptions file so that it now sets PARAMS=BOTH.  It will now
       use both registers AND stack for parameters.
     - Added StormC pragma file in include/StormC_pragmas.


R1.0 V36.0 (May 10 1997):
     - Initial release


R0.0 V00.0 (July 4, 1996):
     - Modemlink Project begins


  - Mike