Copyright  1993 Mark Dignam and Mick Howland - Omen  Computer  Services
         Perth Omen Bulletin Board System - 3:690/660@fidonet

                 The Protocol Engine for Turbo Pascal.
                            version 0.18

   The EASY way to get your Turbo Pascal programs to transfer files!



What is a Protocol Engine?

It  is  a set of software routines that take all the hard work  out  of
writing  communication software.  In this one easy-to-use Turbo  Pascal
(versions  5,  5.5,  6,  7 and Borland Pascal 1.0)  Unit  are  ALL  the
procedures  and functions required to transfer files from one  computer
to  another. Various methods of error checking are available, that  are
fully  compatible  with  the standard protocols  used  by  conventional
terminal programs.


Objectives.

Protocol Engine has been to designed to fufill two major objectives:

a)  It  is very easy to use  for even the novice programmer.  This  was
achieved  by  using  a small linked array of strings  to  transfer  the
filenames  between  the main program and the unit and  then  calling  a
simple Boolean function for each different method.

b)  It has a low DataSegment overhead , while retaining large  Transmit
and Receive buffers. It is suitable for Binkley/FrontDoor transfers and
high  speed modem links. The current DataSegment use is less  than  5k,
while still having up to 15k disk buffering.


Features.

The  Protocol  Engine has support for Xmodem, Xmodem  with  1k  Blocks,
Ymodem Batch, YmodemG Batch, Zmodem (both Crc16 and Crc32), Sealink and
Yapp (a packet radio protocol).

When  using  Zmodem method of transferring files, the  Protocol  Engine
fully  supports crash recovery in both send and receive modes.  In  all
batch modes, there is the option to overwrite or create a new file when
receiving.

Since  Protocol  Engine requires an asynchronous unit  to  handle  high
speed  communications, a Comm unit is included with full  source  code.
This unit is a modified version of the Public Domain ASYNC4. It handles
both Fossil and Non_Fossil environments with ease at speeds upto  38400
baud.

The Protocol Engine also has "external hooks" defined to allow the  end
programmer  to link in their own code into the Protocol  Engine.  These
hooks will be called when certain events happen, as the Protocol Engine
is  being executed. This allows the end user to further  customize  the
look of the Engine, and insert more features into their own software.


Contents of this Archive.

ANSI_DRV.PAS   Source Code for a Ansi Screen Unit
PROTCOMM.PAS   A Half Decent Comms Unit.

The  first two Files are support source code for the  Protocol  Engine.
Users  are  free  to use these files as they wish. The  Ansi  unit  was
written for another project. It may or may not have bugs - it works for
me!  The  Comms unit is a very modified version of ASYNC4  with  Fossil
Support and internal 16650 support.

TERM.EXE   A quick Terminal program written using the Protocol Engine.
TERM.PAS   The source code for the above program.

This demo program shows the use of the Protocol Engine. It has  all  of
the  transfer  protocols in it, along with Ansi and  Doorway  emulation
modes.

The  next  three files are the Turbo Pascal units. The numbers  in  the
extension  field are for the relevant version of Turbo Pascal. To  use:
copy the version that relates to your compiler to Proteng.tpu!

PROTENG.50S     Protocol Engine for Turbo Pascal 5.0
PROTENG.55S     Protocol Engine for Turbo Pascal 5.5
PROTENG.60S     Protocol Engine for Turbo Pascal 6.0
PROTENG.70S     Protocol Engine for Turbo Pascal 7.0 and
                         Borland Pascal 1.0

PROTENG.DOC     This Document!
LICENSE.FRM     License Form - for registration.
PROTMAP.DOC     State Table of all the protocols.


Contacting the Authors.

For  any  further  details or the latest version, the  authors  may  be
contacted at the Perth Omen BBS (3:690/660.0@fidonet) on +61-9-244-2111
(multiline)  all  speeds upto v32, or by voice on  +61-9-244-1954  (any
time between 0300GMT and 1600GMT).

    Mark Dignam.
    Mick Howland.