Contents of the TURBOCOM.DOC file
Copyright 1985 by Don Conover.
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A limited license is hereby granted for non-commercial use and
distribution of this program. No remuneration may be accepted
for this program without my express, written consent.
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Turbocom is a communications program for the IBM-PC and compati-
bles written in Turbo Pascal. Features include automatic dialing
and redialing with a Hayes-type modem and xmodem file transfer
with either checksum or CRC error-checking.
I wrote this program for the experience of learning Pascal. I
purposely kept this program simple to use, and limited the amount
of bells and whistles that I think become a pain after you become
accustomed to a program. Most commands only require one key-
stroke. Further improvements will follow, and I eventually hope
to include batch transfers, support for the kermit protocol, and
The HOME key will display the list of commands available to you.
Most of the commands are similar to PC-Talk or Qmodem and will be
self-evident from the menu.
As mentioned, this program supports Cyclic Redundancy Checking
(CRC) error detection in addition to checksum. CRC is more
accurate than checksum and has been widely used by CP/M modem
programs for several years. It is just now beginning to gain
acceptance in the world of MS-DOS and is supported, for example,
by the FIDO bulletin boards.
The Xmodem protocol is "receiver-driven." Thus, when sending a
file, you do not have to tell Turbocom whether CRC or checksum
should be used. Simply use the pgup key and specify the
filename. Automatic CRC/CHKSUM recognition on send depends on
what the receiving computer sends as a first character.
However, to download a file with CRC, use ctrl+pgdn key rather
than only using the pgdn key as you do for checksum. By using
cntrl+pgdn and then specifying the filename, you invoke CRC.
Turbocom will then automatically tell the receiving computer to
use CRC rather than checksum.
The phone directory is very simple to create. It is an external
file that you write with any editor capable of producing an ASCII
file. Name your phone directory Turbocom.dir and follow this
format: (a) 20 spaces for the telephone number, beginning at
column 0; (b) a comment or description of not more than 20
characters beginning at column 21. For example:
5472008 Computer Connections
A sample phone directory is included in the library.
This program has most of the features necessary for a comm
program to include chdir, log new drive, list files etc... Ascii
transfer was left out since I cannot remember the last time that
I used it. This code has not been completely cleaned up since I
am constantly trying to improve it, and you will find some
procedures not being used and some duplicate procedures.
You can abort from a file transfer by hitting the pgdn key on
downloads and the pgup key on uploads. Redial will redial the
last number until a carrier is detected or a key is pressed.
When you press a key to abort, the redialing will abort after it
completes the dialing cycle. This is one of the routines I plan
Please note that the program hangs up the phone by dropping DTR,
rather than using the less reliable +++, ATH Hayes software
command. However, for this feature to work, make sure that dip
switch 1 on your modem is up rather than down as it is shipped
from the factory. All other dip switch settings are standard.
This program compiles under 30k of code and should run fine on a
64k IBM or compatible. DOS calls were kept to a minimum since I
use an 80t drive on my IBM with Jformat-2, so this program may
run on the not-so-compatible compatibles.
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Enjoy this program, and I hope you find it useful. I am
releasing the source code in the hope that it may be useful to
others in their own work and that others may wish to take the
time to add new features to this program. If you do make changes
to the code, I ask only that you take credit (or blame) for the
changes by putting in appropriate revision notes and that you
share them with me and others by publishing your new source code
and not merely distributing a .com file.
Any suggestions for improvement would be greatly appreciated.
Many thanks to Bob Blacher for his many suggestions and bug
finding. Thanks to Anthony Marcy for help and his suggestions to
keep things simple.
Have a nice day..........don.....