                     ======================================

                          Addenda for DataLink Rv 5.0
                     
                     ======================================


NEW FILE TRANSMISSION PROTOCOL
==============================

When DataLink is used to UPLOAD files to the  SOURCE  using  no  protocol,  as
might  be  the case if one is sending a letter to the MAIL system, priority is
given to transmission. This means that DataLink will fail to receive  some  of
the  characters  being  echoed  back  from  the  SOURCE (or other time-sharing
system). This does NOT mean that the characters were not received by the other
system,  only  that they were lost on echo. If this is not acceptable, the use
of a new protocol - "Echo char" - will cause DataLink to wait for a  character
to  be  echoed  before  sending another character out. It should be noted that
this will cause considerable slowing in effective transmission speed.

LOSING CHARACTERS ON TELENET
============================
When sending files to the SOURCE via Telenet it has been observed  that  under
certain conditions substantial data loss is encountered. Specifically, the use
of a null terminal type at the initial prompt causes this problem  to  appear.
This  is  due the assumptions made about terminal characteristics when no type
is specified. We have found the use of HP26 to both solve this problem and  to
measurably improve characteristics such as type-ahead.

TOUCH-TONE DIALING WITH THE APPLECAT
====================================
The use of a 'T' in a telephone number will cause DataLink to invoke the touch
tone  feature of the Novation AppleCat II, if available. The use of a 'P' will
switch to pulse dialing. Although DataLink will switch  in  the  middle  of  a
number  if requested to do so, the telephone network will NOT be able to cope.
However, if you are using a rotary PBX to make a phone call  which  is  to  be
routed  over a system like MCI or SPRINT you can dial the public access number
using pulse dialing, and then switch to  touch  tone  for  the  long  distance
routing.

SWITCHING COPY FILES WHILE ONLINE
=================================

There is an option available at the command line level which  allows  you  to
specify a copy file. Choosing 'F' (which does NOT appear in the command line)
will cause DataLink to request a file name for copy saving.  If  a  file  has
already  been  assigned, the 'F' command will advise that a file is open, and
ask whether or not that file should be  closed.  For  switching  files  while
online the following sequence may be used.

( assume that a copy file has been established and that there is some data in
the copy buffer )

ESC-S will cause the copy buffer to be flushed to disk

ESC-O returns you to the command line

F asks whether the open file is to be closed

Y causes the file to be closed and a new file name requested.

J returns you to the terminal session

USE OF TESTMACRO FILE
=====================
The macros supplied with the DataLink diskette are for example purposes  only.
The  sample  macros  SOURCE, SOURCET and MICRONET must have actual user id and
password information substituted to be useful.

PRINTING IN HIGH SPEED MODE
===========================
The PRINTING toggle is ignored in high speed mode.    Virtually  none  of  the
printers  generally  available to Apple users can sustain 1200 baud throughput
and therefore any attempt to print would cause data loss.  In order to prevent
this from occurring DataLink refuses to print in high speed mode.

ERRORS WHEN ADDING DEFINITIONS
==============================
An I/O error 8 may result when adding a telephone number or  a  configuration.
This  will  occur if DataLink needs to expand a file and there is another file
immediately adjacent to the file  being  expanded.    If  this  occurs  it  is
necessary to create an opening following the file being expanded. The simplest
way to accomplish this is to examine  the  directory  of  the  disk  on  which
DataLink  resides and to transfer the file whose name FOLLOWS that of DataLink
to itself. For example, if the order of the files on the disk is
  
   COMMFILE3
   TESTMACRO.TEXT

and you are expanding COMMFILE3 then a transfer of 
  
   DLINK:TESTMACRO.TEXT,DLINK:TESTMACRO.TEXT

will normally cause the F(iler to move that file to a different  spot  on  the
disk, leaving an opening following COMMFILE3.

COMMFILE2 contains the configurations, and COMMFILE3 the telephone numbers.

STANDARD CONFIGURATIONS
=======================
The default configuration word format has been changed to 7+ODD+2 as  the  use
of an eight bit protocol caused problems on seven bit systems.

The ABBS configuration word format was changed to 7+ODD+2  as  we  found  more
systems running odd parity than even.

The PASCAL configuration is 8+EVEN+1 rather than having 2 stop bits.

We supplied several additional configurations for various purposes. C-TREE  is
suitable for communicating with COMMUNI-TREE systems, and DATALINK is suitable
for communicating with other terminal programs which may not  support  STX-ETX-
LRCC protocols but will support X-On/X-Off.

GENERATING RUBOUT (DEL) FROM ANY KEYBOARD
=========================================
This  character  was left out of the document inadvertently. To generate a DEL
character from the standard Apple keyboard, use the  ESC  key  followed  by  a
backspace (back arrow).

