Date : 03-12-98      Time : 19:43    Flags  : Public - Unread
From : ISMAEL CORDEIRO               Subj   : Desterm and h/s modems   
To   : NELSON SCHROCK                Area   : CBM-128      

Here are the changes to the Desterm 2.00 setup for working with high-speed
modems. You also have to change the modem setup, enabling software flow
control (XON/XOFF), disabling hardware flow control (RTS/CTS) and setting
it to "locked baud rate" (a.k.a. "locked port rate" or "fixed serial port
rate").

- Protocol Settings
  - Baud rate = 38400 for Swiftlink, CommPort and Turbo232, and 57600 for
                HartCart
  - Xon/Xoff  = Yes

- Modem Settings
  - Hayes/1670 Setup
    - Max Baud Rate    = 38400 for Swiftlink, CommPort and Turbo232, and 57600
                         for HartCart

    - Set Connect Rate = No
    - Initial Sequence = see below

- Transfer Options
  - Incoming Xoff = Honour

- Phone list
  - Baudrate = Max. or 38400 for Swiftlink, CommPort and Turbo232, and 57600
               for HartCart

The intialization strings below configure the modem:

For USRobotics Sportster modems:

ATZ^m~~~AT &B1 &H2 &I2 &R1^m

For Rockwell-chipset-based modems (Boca, Zoom, Hayes, etc.):

ATZ^m~~~~AT &K4^m

You can also save the configuration to the modem's NVRAM and use just ATZ^m as
the initialization string.

                                    -----

Sometimes when you try to upload a file the transfer aborts and the BBS seems
frozen. That happens because of XON/XOFF. When it happens you have just to
press ^Q (control-q) and it'll be alive again.

When the modem is set to XON/XOFF it acts on control characters 17
(XON)(^Q)  and 19 (XOFF)(^S) for controlling the data flow between the
modem and computer. If the file you're trying to upload has a character 19
on it, mainly binary and archived files, or the protocol itself sends a
character 19 the modem interprets the character as a XOFF and stops
receiving data until it receives a XON. So, before uploading you have to
disable XON/XOFF _in the modem_. First you have to put the modem in
command mode by sending the escape string, +++, then you send the command
for disabling XON/XOFF, put the modem back in online mode and do the
upload. When the upload is finished you do the same thing but you send
the command for enabling XON/XOFF instead. It's more easily done than
explained. You can do what I do and put the commands in function keys.

This way you have just to press a few keys to have it done and don't need
to remember the commands.

The Sportster commands are:

- disable XON/XOFF:  &I0
- enable XON/XOFF:   &I2
- go to online mode: O

In the function keys you have to use:

- disable XON/XOFF and go to online mode: AT&I0O^m
- enable  XON/XOFF and go to online mode: AT&I2O^m

The Boca and other Rockwell-chipset-based modems commands are:

- disable XON/XOFF:  &K0
- enable  XON/XOFF:  &K4
- go to online mode: O

In the function keys you have to use:

- disable XON/XOFF and go to online mode: AT&K0O^m
- enable  XON/XOFF and go to online mode: AT&K4O^m

                                    -----

When you send the escape sequence (+++) for putting your modem into command
mode, some remote modems also interpret the three "+" as an escape sequence
and also go into command mode. When that happens your connection with the
remote modem is "frozen". The easiest solution for that problem is changing
the escape character from "+" (ASCII 43) to another character. The one I've
chosen is "@" (ASCII 64). To change it run Desterm 2.00 and change the
initialization string to

ATZ^m~~~AT &B1 &H2 &I2 &R1 S2=64^m

for USRobotics modems, and

ATZ^m~~~~AT &K4 S2=64^m

for Rockwell-chipset-based modems.

The S2=64 command changes the escape character from "+" to "@". Now for
putting your modem in command mode you have just to send @@@ instead of +++.
You should also change the Hangup Sequence in Desterm 2.00 to ~~~@@@~~~ATH^m.

Ismael
... Desterm 2.00 is the best terminal program for the C128.
___ CRR QWK 1.60+

--- Maximus/2 3.01
 * Origin: Juxtaposition BBS.  Lasalle, Quebec, Canada (1:167/133)