[GreenKeys] UPDATE- shockingly basic question - Teletype Model 33 ASR

Tue Feb 9 16:53:20 EST 2021

So RIGHT NOW the machine is running great, just like in the video from
1:42s  onwards.  It also prints perfectly in Local mode as well right now,
no matter how fast I try to type.

However - it will intermittently go back to garbage output, as is shown
prior to 1:42s in the video.

When I was testing in Local last night it was OK typing slowly, but typing
a little fast caused garbage output.

So I think the terminal is intermittently behaving badly, in LIne and Local.

But.. of course... right now it is behaving itself!

cheers
Andy

On Tue, Feb 9, 2021 at 2:21 PM Michael Katzmann <vk2bea at gmail.com> wrote:

> I don't see this as a parity issue. I would expect the ASR33 typing unit
> to ignore parity on receive. Although, I think the tape punch will punch
> the eighth bit (or parity) if received.
> Likewise the tape reader will read and send all eight bits.
>
> Does the ASR read a tape and print consistently in local ?
> I'd be suspicious of the RS232 converter. If you have an oscilloscope and
> can look at the RS232 input compared with the current loop output it may
> prove or dispel this hypothesis.
>
> Michael
>
> On Tue, Feb 9, 2021 at 1:22 PM Andy KN4UCL <kn4ucl at gmail.com> wrote:
>
>> Well I was hoping that it was either my serial loop adapter acting up, or
>> a cabling-from-serial-converter-to-terminal-server problem.  I've replaced
>> everything (including the terminal server) but sadly no obvious fix.
>>
>>    https://www.youtube.com/watch?v=h-w-HCXI25E
>>
>> I've got two similar 33s (both no parity keyboards) and I've had them
>> both running at the same time connected to my terminal server for a while
>> now.  Recently I get very garbled data on one of them. It doesn't seem to
>> be related to the connected equipment or cabling as I've replaced
>> everything.
>>
>> Then... very weirdly it starts working again, as you can see  at 1:42s on
>> the video.
>>
>> Apart from fiddling about with the rangefinder, any other thoughts about
>> (simple 😁) tests or adjustments I can make to diagnose this?
>>
>> thanks folks.
>> Andy
>>
>> On Thu, Feb 4, 2021 at 3:33 PM Andy KN4UCL <kn4ucl at gmail.com> wrote:
>>
>>> OK well this is all very embarrassing. I have two almost identical 33s
>>> (both non-parity) .... the other one works great connected to my Terminal
>>> Server so thought I'd better  swap the RS232 Adapters, port and cable.. and
>>> hey presto - my "not working due to parity errors" Teletype started running
>>> fine!
>>>
>>> I then swapped back to the original RS232 adapter, cables and port...
>>> expecting things to NOT work... but of course, everything ran fine (sigh.)
>>>
>>> I've tried jiggling the cables (I was hopeful maybe a weird cable
>>> problem could be the issue) but I am struggling to see how a wiring problem
>>> would look like a legit parity problem.
>>>
>>> Anyway! All good for now.. but I am curious what would cause these
>>> parity-like symptoms. I am going to replace the cables anyway, and probably
>>> grab another RS232 converter just in case.
>>>
>>> cheers!
>>> Andy
>>>
>>> On Wed, Feb 3, 2021 at 11:05 PM Mike Douglas <deramp5113 at yahoo.com>
>>> wrote:
>>>
>>>> Since you are concerned about the parity of your keyboard while testing
>>>> the TTY printing function, I assume your terminal server is in a mode where
>>>> it echos characters that you type on the TTY keyboard back out to the TTY
>>>> printer and you are testing your printer by typing on the TTY keyboard?
>>>>
>>>> If this is what you’re doing and you have a non-parity keyboard, then
>>>> set the serial port to 7 data bits plus mark parity (non parity keyboards
>>>> set the 8th bit to one). This should ensure the server accepts the typed
>>>> characters. If you type one character at a time with a short pause between
>>>> each character, then each character should echo properly to the TTY
>>>> printer. The pause between each character will be more than the two stop
>>>> bits the printer requires (and the printer ignores the 8th bit).
>>>>
>>>> If, however, you have a telnet session open and are sending data from a
>>>> remote device to the TTY printer and are not using the TTY keyboard to
>>>> generate test data, then set the serial port to 8 data bits plus mark
>>>> parity. This will appear as 8 data bits and 2 stop bits to the printer (as
>>>> it requires) and the printer can then keep up with a steady stream of data.
>>>>
>>>> If you are getting some garbage characters with either of these methods
>>>> but everything prints correctly in local mode, you made need to adjust the
>>>> rangefinder a bit.
>>>>
>>>> Mike
>>>>
>>>> On Feb 3, 2021, at 9:22 PM, Andy KN4UCL <kn4ucl at gmail.com> wrote:
>>>>
>>>> 
>>>> My Teletype has a Deramp converter which goes direct into an Equinox
>>>> ELS-16 terminal server.  When I start I get a session with the terminal
>>>> server and can interact directly with the server ... or telnet onwards
>>>> elsewhere.
>>>>
>>>> On Feb 3, 2021, at 10:00 PM, Mike Douglas <deramp5113 at yahoo.com> wrote:
>>>>
>>>> 
>>>> I guess I’m confused as to your test setup then. What is sending data
>>>> to your Teletype? Is it coming from an external source other than the
>>>> Teletype, or are you testing by somehow looping keyboard input from your
>>>> TTY back out to the TTY printer?
>>>>
>>>> Mike
>>>>
>>>> On Feb 3, 2021, at 8:36 PM, Andy KN4UCL <kn4ucl at gmail.com> wrote:
>>>>
>>>> 
>>>> I think I am still missing a trick or two here...I tried every
>>>> combination of 8 and 7 even/odd/none/mark/space and I get no printing at
>>>> all with 8 bit, but moderately bad spelling errors with 7.  See attachment
>>>> below... presumably this means I have the non-parity keyboard?
>>>>
>>>> thanks in advance for your thoughts!
>>>> Andy
>>>>
>>>> On Sun, Jan 31, 2021 at 8:18 PM Mike Douglas <deramp5113 at yahoo.com>
>>>> wrote:
>>>>
>>>>> If you select 8 bit with mark parity on your terminal server, you’ll
>>>>> probably get the 8N2 timing the Teletype requires (the mark parity bit
>>>>> serves as the first stop bit).
>>>>>
>>>>> Mike
>>>>>
>>>>> On Jan 31, 2021, at 7:11 PM, Andy KN4UCL <kn4ucl at gmail.com> wrote:
>>>>>
>>>>> 
>>>>> Thanks guys for the responses - a lot of great info for me to digest!
>>>>>
>>>>> My terminal server (Equinox ELS-16) allows me to define character size
>>>>> as 7 or 8 bits, and to set parity as NONE, ODD, EVEN, MARK or SPACE.
>>>>>
>>>>> I don't seem to have the ability to specifically state the number of
>>>>> stop bits, however.
>>>>>
>>>>> Anyway.. I'm going to crack my Teletype open and confirm exactly
>>>>> what's going on.
>>>>> cheers!
>>>>> Andy
>>>>>
>>>>> On Sun, Jan 31, 2021 at 5:43 PM Keith Lueck <kwlueck at swbell.net>
>>>>> wrote:
>>>>>
>>>>>> Jim & Wayne are spot-on, of course.  I learned the hard way that you
>>>>>> best include the parity bit - even though the 33 doesn't give a whit about
>>>>>> parity...
>>>>>> My machine was occasionally producing errors when I was feeding it 7
>>>>>> N 2.  Wayne Durkee set me straight, and, viola, when I sent it 7 M 2,
>>>>>> everything was 100% ducky.
>>>>>>
>>>>>> On Sunday, January 31, 2021, 03:32:30 PM CST, Jim Haynes <
>>>>>> jhhaynes at earthlink.net> wrote:
>>>>>>
>>>>>>
>>>>>> All the 33s and 35s generate 11 unit code.  1 start bit, 7 data bits,
>>>>>> one
>>>>>> bit which may be even parity or may be marking, and two stop bits.
>>>>>> That's
>>>>>> where 110 baud comes from. 100 wpm = 10 chars/sec and each char
>>>>>> contains
>>>>>> 11 bits.  The reason for two stop bits is the difficulty of making a
>>>>>> mechanical selector that is reliable at 100 wpm.
>>>>>>
>>>>>>     ---
>>>>>>
>>>>>>     "Ya can argue all ya wanna, but it's dif'rent than it was."
>>>>>>     "No it ain't! No it ain't!  But ya gotta know the territory."
>>>>>>         Meredith Willson, The Music Man
>>>>>>
>>>>>> ______________________________________________________________
>>>>>> 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
>>>>>>
>>>>>> >>> Jordan Spencer Cunningham's GreenKeys Search Tool:
>>>>>> https://teletype.net/gksearch
>>>>>> >>> 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
>>>>>> Message delivered to kwlueck at swbell.net
>>>>>>
>>>>> ______________________________________________________________
>>>>> 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
>>>>>
>>>>> Jordan Spencer Cunningham's GreenKeys Search Tool:
>>>>> https://teletype.net/gksearch
>>>>>
>>>>> 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
>>>>> Message delivered to deramp5113 at yahoo.com
>>>>>
>>>>> <non parity keyboard.png>
>>>>
>>>> ______________________________________________________________
>> 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
>>
>> >>> Jordan Spencer Cunningham's GreenKeys Search Tool:
>> https://teletype.net/gksearch
>> >>> 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
>> Message delivered to vk2bea at gmail.com
>
>
>
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/greenkeys/attachments/20210209/5c375164/attachment.html>