[Ham-Computers] RE: TTY/TDD For windows?

[Hsu, Aaron (NBC Universal)]

I'm not familiar with the technical aspects of TTY, but here's a link to the
TTY FAQ:
http://www.zak.co.il/deaf-info/old/tty_faq.html

Connecting your modem to your friend's TTY depends on weather or not your
modem supports 45.5 BAUD BAUDOT coding...probably not.  If your friend has a
newer TTY device, then it might also support 300 BAUD ASCII.  Most modems
will do 300 BAUD without a problem.  In fact, that first long "eeeeee" sound
you hear eminating from a modem is the initial 300 BAUD handshake prior to
negotiating a higher speed.

Not quite sure, but you might also need TTY specific software.  Read through
the FAQ...it might point you in the right direction.

If you already know you need 300,N,8,1 (300 BAUD, no parity, 8 data bits, 1
stop bit), then the modem should auto-handshake to that rate.  If not, there
are modem specific commands to force the rate.  The Hayes command set is
standardized up to a certain point.  Then there are "extended" commands that
are specific to modem brands or chipsets.  Unfortunately, locking the sync
rate is usually an "extended" command.  For example, "AT&N2" locks my modem
(a USR Courier) at a max sync rate of 300 BAUD.  The "&" donates an extended
command, the "N" is the actual command, the "2" is the setting for 300 BAUD.

The most common character for extended commands is the "&" character.  It's
most likely that your modem will have an extended command to lock or limit
the sync rate.  USR modems have a built in help table by using the "$"
character.  For example, AT$ lists the standard command set common to almost
all "Hayes" style modems.  You can also use "AT&$" to get a list of the USR
extended commands.  For reference, there are also some other extended
commands that some USR modems support such as "%" and "#".

Here's a link I just found for Hayes commands...don't know if they're
specific to Hayes branded modems, but it a good start.  Unfortunately, at
quick glance, I can't find a command to lock the sync rate.
  http://readthetruth.com/modems.htm

Try a Google search on "Hayes AT Commands sync rate" and you might find
additional useful links.

Good luck!

  - Aaron, NN6O



-----Original Message-----
From: Paulahkolik at aol.com [mailto:Paulahkolik at aol.com] 
Sent: Monday, January 24, 2005 8:48 AM
To: ham-computers at mailman.qth.net
Subject: Re: [Ham-Computers] TTY/TDD For windows?


Thanks to everyone who's responded so far. I think I incorrectly phrased the

question, so I'll ask it again.

I'm using a V92 modem. How do I "slow it down" so as to be able to call a 
TTY/TDD user? I've been through the manual, and can't find instrcutions on
this. 
Is there softwware to do this, or can I do it manually?

Paul W5PDA/4