[GreenKeys] UPDATE- shockingly basic question - Teletype Model 33 ASR
Michael Katzmann
vk2bea at gmail.com
Tue Feb 9 19:20:51 EST 2021
Try swapping the selector magnet driver card between the two units. (
vertical card on the right hand edge). If you are having problems in local
then it is not the RS232-current loop circuit but it might be the magnet
driver.
On Tue, Feb 9, 2021 at 4:53 PM Andy KN4UCL <kn4ucl at gmail.com> wrote:
> 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
>>
>>
>>
>>
>>
>> --
|\ _,,,---,,_ Michael Katzmann
/,`.-'`' -. ;-;;,_ NV3Z / VK2BEA / G4NYV
|,4- ) )-,_. ,\ ( `'-'
'---''(_/--' `-'\_) vk2bea at gmail.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/greenkeys/attachments/20210209/582da194/attachment.html>
More information about the GreenKeys
mailing list