[GreenKeys] Interface ASR33 to Linux serial port

Michael Katzmann vk2bea at gmail.com
Sun Jan 14 18:55:14 EST 2024 

Yes, Johan helped me submit the patch and also corresponded with a chap at
Prolific (although from memory he was only useful in confirming we were on
the right track).
The version I worked on was the TA variant. I think there are newer
versions but the TA is .... prolific 😸

https://github.com/torvalds/linux/commit/764de1059b97ca1fe8fe023bb10e736772945c87

Michael


On Sun, Jan 14, 2024, 17:29 fretless <fretless52 at gmail.com> wrote:

> *** Sorry. I hope this one doesn't screw up the subject line this time***
>
> Nice work Michael.
> In Jan/Feb 2021 I was working with Johan at kernel.org trying
> to get my Prolific dongle to work with my 33.  It worked fine in
> Windows so I knew it wasn't a hardware issue.  I was able to
> hard code the USB initialization string that I captured in Windows
> into the Linux driver and get it to work at 110b, but I was not able
> to figure out how to modify the code to generate the string
> automatically using the divisor routine.
>
> I was still receiving updates from kernel.org a few weeks later and
> saw where you were having the same issue and were eventually
> able to get the driver to generate the correct initialization string.
>
> I had to put my 33 in storage shortly after that and haven't been able to
> use it.  Hopefully, I will be retrieving it soon.
>
> Joe
>
> On Tue, Jan 9, 2024 at 12:20 PM <greenkeys-request at mailman.qth.net> wrote:
>
>>
>>
>> I did some work on the Linux Prolific driver to get it to work with
>> arbitrary baud rates (e.g. 110). There are several variants and the one I
>> had did not give the right speed when set to 100. I was able to reverse
>> engineer it (with a lot of trial and error) and now AFAIK all the
>> variants now work.
>> https://github.com/torvalds/linux/blob/master/drivers/usb/serial/pl2303.c
>>
>> Michael
>>
>>
>> On Tue, Jan 9, 2024 at 12:38?PM Eric Moore <mooreericnyc at gmail.com>
>> wrote:
>>
>> > DriverGenius 4 Port USB to Serial RS232 DB9 Adapter Coverter with 12 X
>> > LEDs - Win11 & Mac (4XRS232, Metal) https://a.co/d/6xXQ0fy
>> >
>> > This is what I use, definitely does 110 baud on all 4 ports, should do
>> > lower.
>> >
>> > Uses the PL2303 I think, the FTDI I have had issues at low speeds.
>> >
>> > -Eric
>> >
>> >
>> > On Tue, Jan 9, 2024, 11:13?AM Chuck Rehor <chuck at rehor.com> wrote:
>> >
>> >> Hi GreenKeyers,
>> >>
>> >>
>> >>
>> >> In the past for my RS-232 projects when I?ve needed serial
>> >> communications, I ran into unexplained problems with
>> USB-to-RS232-Serial
>> >> converters incorporating the Prolific chipset. Since Prolific has
>> become
>> >> so, well, prolific, it has a huge market share, so foreign companies
>> have
>> >> knocked off the Prolific chip and flooded the market with counterfeit
>> chips
>> >> marked Prolific, but are NOT Prolific brand.  These counterfeit chips
>> have
>> >> flooded the electronics parts supply chain, and therefore, have been
>> >> inadvertently used in even legitimate companies' USB adapters (even
>> >> name-brand companies).  To protect themselves, Prolific finally changed
>> >> their drivers so that their drivers are on the lookout for bogus
>> chips. I
>> >> think those Prolific drivers are part of the Microsoft Plug-n-Play
>> >> devices.  If the new Windows driver finds a counterfeit chip being
>> used on
>> >> the system, the driver will give a warning and disable the device by
>> >> overwriting the driver on your system. With the RPi running its
>> version of
>> >> Linux, I?ve scratched my head trying to get gettys to run right
>> because it
>> >> might show the login prompt, but either not accept characters, or it
>> >> accepts characters but would not give me a Password prompt, so I
>> couldn't
>> >> get logged in. Searching on the internet, I saw other people had
>> problems
>> >> with the Linux drivers too.
>> >>
>> >>
>> >>
>> >> So I?ve given up on Prolific and only use devices which use the FTDI
>> >> chipset. If a device doesn't specifically say it uses the FTDI chipset,
>> >> chances are it doesn't, so I don?t bother with it.
>> >>
>> >>
>> >>
>> >> Recently I?ve had great luck with Gearmo 4-Port RS232 to USB FTDI chip
>> >> Adapter w/RX and TX Status LEDs (
>> >> https://www.amazon.com/Gearmo-Port-RS232-Adapter-Status/dp/B08P24ZQ1B
>> >> $44). It comes in a version that doesn't have the status LEDs for a few
>> >> dollars cheaper, but LEDs are well-worth it when trying to debug
>> something.
>> >>
>> >>
>> >>
>> >> If you only need one RS-232 port, I can recommend Gearmo's USB to
>> Serial
>> >> RS-232 Adapter with LED Indicators FTDI Chipset (
>> >> https://www.amazon.com/gp/product/B00AHYJWWG   $23).
>> >>
>> >>
>> >>
>> >> The only thing I can't verify is if it goes down to 110 baud (I don't
>> >> have a 110-baud device in the same location).  I did connect Ports 1 &
>> 2
>> >> together (via a null modem connector) and opened two putty sessions
>> set for
>> >> 110 baud, 8 bits, 1 stop, no parity, xon/xoff, and it seemed to work (I
>> >> could send characters back and forth between windows).  I used putty
>> >> version 0.78 on Windows 11 and a command line of: "C:\Chuck> putty
>> >> -serial COM5 -sercfg 110,8,1,n,X" because I could never correctly
>> configure
>> >> putty with its GUI.  However, when I opened a putty session for 300
>> baud
>> >> and kept the other at 110, I expected I couldn?t communicate between
>> them,
>> >> but lo and behold, it worked anyway, so I?m not sure it actually went
>> down
>> >> to 110 and 300 baud.  Maybe it defaults to a certain speed if someone
>> tries
>> >> to give it a speed it can't handle.  Like I said, I don?t have a 110
>> baud
>> >> terminal in the same location so I couldn?t really verify 110 or 300
>> baud
>> >> operation, but sometime I will and report back.
>> >>
>> >>
>> >>
>> >> Hope the above helps.
>> >>
>> >>
>> >>
>> >> Chuck
>> >> W9CFR
>> >>
>> >> On Mon, Jan 8, 2024 at 2:36?PM Tom Lake <tlake at twcny.rr.com> wrote:
>> >>
>> >>> I have a PiDP-11 as well and the Teletype works fine with it. I
>> replace
>> >>> the PiDP-11 with the Pi 5 using the same RS-232 converter and I can?t
>> log
>> >>> into Linux with the Teletype.
>> >>>
>> >>>
>> >>>
>> >>> *From:* Michael Katzmann <vk2bea at gmail.com>
>> >>> *Sent:* Thursday, January 4, 2024 5:33 PM
>> >>> *To:* tlake at twcny.rr.com
>> >>> *Cc:* greenkeys at mailman.qth.net
>> >>> *Subject:* Re: [GreenKeys] Interface ASR33 to Linux serial port
>> >>>
>> >>>
>> >>>
>> >>> I've got a PiDP11 with a 33 attached.
>> >>>
>> >>> Usually the 33 is driven off the PDP11/70 SIMH emulator.
>> >>>
>> >>> I tried running the agetty command as you showed and it looks like it
>> >>> worked (except bash is confused for some reason)
>> >>>
>> >>> The OS is Raspbian (32 bit) but its pretty close to Ubuntu (both based
>> >>> on Debian). I favour Fedora myself!
>> >>>
>> >>>
>> >>>
>> >>> Michael
>> >>>
>> >>>
>> >>>
>> >>>
>> >>>
>> >>>
>> >>>
>> >>> On Thu, Jan 4, 2024 at 3:52?PM Tom Lake <tlake at twcny.rr.com> wrote:
>> >>>
>> >>> I have an Ubuntu 23.10 system with agetty running on its eight serial
>> >>> ports. I can hook up most terminals to the ports and login to a bash
>> shell.
>> >>>
>> >>> When I try to use a Teletype ASR 33, however, I get the login prompt
>> and
>> >>> I answer enter the username. If I hit Return, nothing happens. If I
>> hot
>> >>> Line Feed, the Password prompt is shown.
>> >>>
>> >>> After I enter the password (all uppercase) Incorrect password is
>> shown.
>> >>>
>> >>>
>> >>>
>> >>> Since the prompts are displayed properly, I?m pretty sure the baud
>> rate,
>> >>> BPS and stop bits are correct. What else can I check?
>> >>>
>> >>>
>> >>>
>> >>> I start agetty this way:
>> >>>
>> >>>
>> >>>
>> >>> agetty  -L -U ttyUSB0 110 tty
>> >>>
>> >>>
>> >>>
>> >>> The -L means it?s a dedicated line, not dial-in. The -U means the
>> >>> terminal is uppercase only and some upper/lowercase conversions
>> should be
>> >>> made.
>> >>>
>> >>> The port is a USB to serial port (ttyUSB0), baud is 110.
>> >>>
>> >>> ______________________________________________________________
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>> >>>
>> >>> >>> Jordan Spencer Cunningham's GreenKeys Search Tool:
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>> >>> >>> 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-  ) )-,_. ,\ (  `'-'
>> >>>  '---''(_/--'  `-'\_)
>> >>>
>> >>>
>> >>> ______________________________________________________________
>> >>> 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 chuck at rehor.com
>> >>>
>> >> ______________________________________________________________
>> >> GreenKeys mailing list
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>> >> 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 mooreericnyc at gmail.com
>> >
>> > ______________________________________________________________
>> > 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-  ) )-,_. ,\ (  `'-'
>>  '---''(_/--'  `-'\_)
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>> End of GreenKeys Digest, Vol 240, Issue 10
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> ______________________________________________________________
> GreenKeys mailing list
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> 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
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