[GreenKeys] Computer Questioon

Tue Aug 18 18:36:58 EDT 2015

Hi All,
OK I am not the sharpest tool in the shed when it comes to computers. I know 
just enough to get myself in trouble.

That said, I have a question.
It seems that to interface a TTY to a computer you have the following possible 
contentions.
25 pin rs232 now obsolete
9 pin rs232 ditto
usb 2.0 being upgraded to 3.0. Different drivers for different machines,
Different versions of windows or Linux which affects the above.
Not all drivers support low speed 45.5 or 50 baud.

But when you interface through the soundcard you can
use any soundcard
use any computer
support any slow speed desired.
If someone has gone to the trouble of finding a mechanical TTY you can be 
pretty sure they have a converter with loop supply.

ITTY is a great example. I can run it from my laptop or any other computer past 
or present.
Wouldn't be simpler to have comms programs write/read to a soundcard instead of RS232? Or am I missing something here?

Thanks,
Keith ve3ts

---
New Outlook Express and Windows Live Mail replacement - get it here:
http://www.oeclassic.com/

Original Message:
From: simon <simski at dds.nl>
To: <greenkeys at mailman.qth.net>
Sent: 2015-08-16 5:39:41 PM
Subject: [GreenKeys] A reliable current-loop-to-RS232 converter

On 16-08-15 02:21, Bob Camp wrote:
> Hi
>
> The fine people “across the sea” will gladly sell you a RS232 <-> TTL converter mounted on a board with connectors.
> Depending on how picky you are it may or may not cost you as much as lunch at MacDonalds (including shipping over
> the ocean). If time is critical, the usual suspects here in the US will sell you a slightly fancier version (still fully assembled)
> for a bit more.
>
> Bob
>
>
>> On Aug 15, 2015, at 7:02 PM, drlegendre . <drlegendre at gmail.com> wrote:
>>
>> To convert the TTL level RS-232 signals to a proper bi-polar signal, you only need a MAX232 chip (or clone) and 4x 1uF @ 16V capacitors. The MAX232 directly converts back and forth between 5V TTL and the more correct +/-12V signaling.
>>
>> Easy as pie, and the chips are like a buck or something. Let me know if you need one, I have a couple spares.
>>
>> On Sat, Aug 15, 2015 at 3:24 PM, <teletypeparts at comcast.net> wrote:
>> Justin,
>>
>> Thanks for your input. Gabriel's 
33 is configured for full duplex, 20MA, 4 wire connection. 
That's the way I sent it to him unless I made a mistake, but don't think so as 
the cable on the UCC-6 was already in place and likely was used on a computer 
before. I just checked the connections and labeled the line cord end. 20MA is 
easy to check, just look at the large green resistor in the UCC-6 and the left 
tap should have a wire on it. 60MA, the wire goes to the inside tap. I also 
tested the machine with a signal generator at 20MA, full dux.
>>
>> I 
don't want to confuse the issue if possible. The 33 should work to a RS-232 adapter. The problem is there are so darn many and they don't 
have a good track record. I have seen lots of 33 owners struggle with this 
issue. It almost always came down to the RW-232 adapter.
>>
>> Best regards,
>>
>> Wayne
>>
>>>
and maybe jump one conversion step with a usb to serial converter like 
the ftdi or a arduino leonardo with out of the box democode. dx.com and 
banggood.com have them in 5 and 3.3v versions
http://www.dx.com/s/serial+usb

And take a look here:

wiki.edwindertien.nl/doku.php?id=modules:telex

Simon (who implemented a version on a Raspberry Pi as the uart can talk 
any BAUD you like, for example 58baud (dont ask... long story))

-- 
Met vriendelijke Groet,

Simon Claessen
drukknop.nl
______________________________________________________________
GreenKeys mailing list
Home: http://mailman.qth.net/mailman/listinfo/greenkeys
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:GreenKeys at mailman.qth.net

2002-to-present greenkeys archive: http://mailman.qth.net/pipermail/greenkeys/
1998-to-2001 greenkeys archive: 
http://mailman.qth.net/archive/greenkeys/greenkeys.html
Randy Guttery's 2001-to-2009 GreenKeys Search Tool: http://comcents.com/tty/greenkeyssearch.html

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/greenkeys/attachments/20150818/8386fec1/attachment.html>