Hayes modem for 3B2

Frank "crash" Edwards crash at tsc3b21.UUCP
Wed Feb 24 00:56:55 AEST 1988


>From article <450 at stech.UUCP>, by sysop at stech.UUCP (Jan Harrington):
> in article <220 at mccc.UUCP>, pjh at mccc.UUCP (Peter J. Holsberg) says:
>> 
>> In article <449 at stech.UUCP> sysop at stech.UUCP (Jan Harrington) writes:
>> |Please help.  I've got a 2400 baud Hayes-compatible modem, an AT&T 3B2/400, and
>> |Unix System V version 3.0.  I desperately need to get this modem working --
>> |bidirectionally.  Upgrading to 3.1 isn't possible at this time (absolutely
>> |_NO_ money available).  Is there any way to do this?
>> 
>> Well, I'm all for getting gratitude, undying or other, but what seems to
>> be the problem?  Set up the port with SYSADM, hook up the modem, send it
>> the AT string tha silences the bugger (ATE0Q1), and you should be in
>> business.  But perhaps you've done this and still have a problem?  
> 
> It's a MAJOR problem - as shipped, the Hayes dialer won't support
> bidirectional transmissions.  This modem is for a machine that runs a
> bulletin board, which means it must answer the phone unattended.  It also
> polls another system for news, which means it must dial out unattended.
> There is only one phone line in and out of this machine (no - I can't add
> another one - no wiring in the house!)
> 
> Jan Harrington, sysop
> Scholastech Telecommunications
> ihnp4!husc6!amcad!stech!sysop or allegra!stech!sysop

Following is a couple of lines out of my Dialers file on a 3B2/310:
------------------------------------------------------------------------------
hayes	=,-,	"" \dATZ\p\r\c "" \dAT\pS0=4\pQ0\r\c OK\r \dATDT\T\r\c CONNECT-ATQ1\r\c \d+++\d OK\r \pATQ1\pO\r\c
reset	=-,-	"" \dATZ\p\r\c "" \dAT\pS0=4\pQ1\r\c
------------------------------------------------------------------------------
The first entry, "hayes", first resets the modem ("ATZ"), then sets the auto-
answer to 4 rings ("ATS0=4") [you may want a different value -- anything but
zero!], then dials the number ("ATDT\T").

The reset sequence turns off the no-echo/no-response modes of the modem.
This allows the script to check for OK and CONNECT.  It also makes sure
that the modem is configured as per the dip switches (more on that later).

When the CONNECT is received by the dialer, it proceeds to send the escape
characters ("+++") preceded and followed by a short delay ("\d").  This
puts the modem in command mode.  Command mode is required to change the
modem BACK to the no-response status.  Setting the no-echo mode is optional,
BUT IT IS MUCH EASIER AND LESS HEADACHES TO TURN OFF ECHO.

I've included the "reset" dialer -- it's use is for those times when the
line gets dropped unexpectedly while inside "cu" and "cu" doesn't clean_up
properly (BTW, does anyone else have this problem?).  I use "cu reset" 'cuz
I also have a line in my Systems file for a machine called "reset".

Now if I could only find some *EASY* way to fix the DCD/DTR brain-damage ;-).


"Use the Source, Luke.  Feel it flow through your fingertips..."
-----
Frank (crash) Edwards		...!codas!usfvax2!{pdn,jc3b21}!tsc3b21!crash
TSC in Palm Harbor, FL		Phone:  (813) 785-0583  (voice)
The Sweat Shop
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