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* [COFF] 52-pin D-Sub?
@ 2020-02-29  9:59 rudi.j.blom
  0 siblings, 0 replies; 27+ messages in thread
From: rudi.j.blom @ 2020-02-29  9:59 UTC (permalink / raw)


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Not UNIX, not 52-pin, but old, old and serial

Your mission, should you choose to accept it, is to save data from a
computer that should have died aeons ago
...
Tap into the serial line – what could be simpler?
Alas, the TI was smart enough to spot the absence of the rattly old
beast ("the software wouldn't print without some of the seldom-used
serial control lines functioning," explained Aaron) so the customer
was asked to bring in the printer as well.

https://www.theregister.co.uk/2020/02/24/who_me/


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* [COFF] 52-pin D-Sub?
  2020-02-28 23:40                     ` pechter
@ 2020-02-29 16:52                       ` clemc
  0 siblings, 0 replies; 27+ messages in thread
From: clemc @ 2020-02-29 16:52 UTC (permalink / raw)


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On Fri, Feb 28, 2020 at 6:40 PM William Pechter <pechter at gmail.com> wrote:

> Most of the RS232 spec seemed to be designed for Sync modems and their
> management.
>
> Most machines of the mini generation seemed to use either Async or Sync
> interfaces.  Stuff like the VT180 had a comm port that was a 8251  USART
> for serial comm that could be either sync or async.  I don't believe Dec
> had anything like that in that PDP11 or early Vax days.
>
> Anyone care to enlighten me?
>
I know some of the story having known some of the players and lived a
little of it, but I do not claim to know all of it.  So I might be able to
fill in some holes, but there is still plenty missing from the complete
story.

First, remember RS-232 is an ECMA spec for connecting communication gear to
data gear.  It's not so much about sync/async as it dealing with the phone
systems in the US and Europe and how to interface computer gear to it.
 The driver of the spec was building and connecting RJE-like systems for
banks and financial institutions, airline terminals, *etc*. to connect to a
central (mainframe) computer.   This is why it uses terms like "Data
Communications Equipment" and "Data Terminating Equipment" - as opposed to
modems, computer terminals, hosts and the like.

Different systems vendors had different ways of thinking about the computer
they were selling and how people would interface with them.   And you can
see the differences in the choices they make in gear like the peripherals
that they interface at the time.

The AT&T Teletype Model 28 (https://en.wikipedia.org/wiki/Teletype_Model_28
  circa 1953 intro, 5-bit BAUDOT code, current loop) was the standard
terminal on DEC systems for many years.    Gordon Bell invented (patented)
the UART to talk to it for the PDP-1 (maybe it was the PDP-6) sometime in
the early 1960s.   What I do not know/understand is what was the work he
did at DEC and what when he had left to be a CMU prof.  I was >>under the
impression<< the patent was granted during his CMU time; but I had thought
DEC originally built them as FLIP-CHIPS for the PDP-6.

Then in 1963, 7-bit ASCII was introduced.  IBM and AT&T were to two
biggest firms
behind it (remember that the IBM System 360 was supposed to be an ASCII
system and has a lot of support for ASCII in its ISA; but due to the OS SW
being late that stayed with their earlier BCD – creating EBCDIC - read Fred
Brook's "The Mythical Man-Month
<https://en.wikipedia.org/wiki/The_Mythical_Man-Month>" for the details).
However AT&T, GE and DEC did switch to 7-bit ASCII pretty much as soon as
they could.   The AT&T/Teletype Model-33 (
https://en.wikipedia.org/wiki/Teletype_Model_33   circa 1963 intro, 7 bit
ASCII code/current loop, but lacked shift key on the keyboard) was
introduced soon thereafter and that became the standard terminal (7-bit
byte, plus parity and 3 bits worth of start/stop -- 11 serial bits per
transmission).   My memory is that AT&T did not make sell an ECMA RS-232
version, but the aftermarket had a ton of converters between the current
loop interface at the ECMA standard.

So at the time, you have IBM using primarily synchronous interfaces, while
AT&T (Teletype) used asynchronous.  IBM liked sync because of the fact that
it needed no wasted start/stop bits. They liked 1/2 duplex because their
devices were primarily going one way at a time.  In the 60s, IBM's big
business has them connecting RJE stations and they would only much later do
1/2 duplex synchronous* terminals*.    DEC was more interactive much
sooner, used Teletype's and thus was async and full-duplex.

I was also under the impression (*i.e.* once was told) that Western Digital
obtained a license to make the UART as chips but it was never completely
clear to me who held the patent (CMU or DEC) *i.e.* who/how WD got the
license from.  But after the chips appeared, DEC would buy those chips from
WD for things like the DL/KL-11's and DH-11 interfaces and I think they
made something like the DL11 for the PDP-8.  If you look at the schematics
for the early serial ports for the PDP-11, they are all using the same WD
chip.

Soon after the UART, WD also starts making a USRT, which (the best I can
tell) they seem to be selling to IBM and the com vendors for IBM gear.   I
personally never programmed them, but they are in an old WD book I once had
(may still).  I remember seeing them in some Gandalf gear in the mid-70s
besides the IBM gear, but I don't known/remember much more.

In the early 1970s, CMU used the same WD UART chips as DEC was using in the
DL-11, but had designed their own serial board, which we called the ASLI
(there were other differences but mostly the SW could not tell the
difference).

Nat Semi was a second source for WD at some point in the late 1960s, and by
the early 1970s, they started to design there own UART (as was pointed out
eventually they created 8250 and it's follow ons).  I'm not sure when Intel
and Moto started to make them, but I think both the 8080 and 6800 families
had UARTs chips.   MOS Tech did not originally, although later when
Rockwell became their second source, a UART for that family appeared too.

At some point in the early 1970s, the first USARTs start to appear.    I
was under the impression, WD was the origin of them, but I do not know.
By the time of the 16-bit micros, however, many of the better serial
interface chips could be either synchronous or asynchronous under program
control.  With the 16-bit chips, a Zilog USART chip was fairly popular at
one point from Macs to UNIX boxes.  As other pointed out, because of the
PC/AT the Nat Semi 8250 stuck around as it had ended up are part of the 'PC
support chip family', even though it was a bit of dog and notorious for
dropping characters at high speeds.

For completeness, the Unix folks at BTL used the Teletype Model 37 (
https://en.wikipedia.org/wiki/Teletype_Model_37   ß 1968 intro, 7 bit ASCII
code, full U/L case ) as their native printing terminal.   IIRC the ASR-37
had an RS-232C option as well as a current loop one from Teletype as the
industry had pretty much dropped off of the current loop standard by
then. Interesting side note, the AT&T/BTL programmers often did not have
'hardwired' lines in their offices, but used modem (there was the phone
company of course).
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* [COFF] 52-pin D-Sub?
  2020-02-29 15:45                         ` krewat
@ 2020-02-29 15:49                           ` clemc
  0 siblings, 0 replies; 27+ messages in thread
From: clemc @ 2020-02-29 15:49 UTC (permalink / raw)


On Sat, Feb 29, 2020 at 10:45 AM Arthur Krewat <krewat at kilonet.net> wrote:

>
> You technically haven't lived until you use an acoustic coupler, a
> cassette tape recorder and a wire tap to record 300 baud modem tones as
> you type out files on a PDP-10 somewhere...
>
> And then play that tape back to your own computer and that same modem,
> and save it to floppy.
>
And we thought that was so cool and high tech in those days .....
particularly using 30 cps vs 10 cps of the ASR33.
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* [COFF] 52-pin D-Sub?
  2020-02-29 13:12                       ` emu
@ 2020-02-29 15:45                         ` krewat
  2020-02-29 15:49                           ` clemc
  0 siblings, 1 reply; 27+ messages in thread
From: krewat @ 2020-02-29 15:45 UTC (permalink / raw)


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On 2/29/2020 8:12 AM, emanuel stiebler wrote:
> On 2020-02-28 18:22, William Pechter wrote:
>
>> I used to be the guy who
>> at the most desperate would get Kermit over a 3 wire interface to allow
>> data transfer between different systems.  Or UUCP on ms-dos...
>>
>> Something about jack of all trades.
> Kermit seems to be or was(?) the Swiss army knife of communications.
> Or the 9-track tape ...
> ;-)
>
>
You technically haven't lived until you use an acoustic coupler, a 
cassette tape recorder and a wire tap to record 300 baud modem tones as 
you type out files on a PDP-10 somewhere...

And then play that tape back to your own computer and that same modem, 
and save it to floppy.

It's how I saved LOGO.MAC from somewhere on the ARPANET back in the 
early-to-mid 80's.

;)

art k.





^ permalink raw reply	[flat|nested] 27+ messages in thread

* [COFF] 52-pin D-Sub?
  2020-02-28 23:22                     ` pechter
@ 2020-02-29 13:12                       ` emu
  2020-02-29 15:45                         ` krewat
  0 siblings, 1 reply; 27+ messages in thread
From: emu @ 2020-02-29 13:12 UTC (permalink / raw)


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On 2020-02-28 18:22, William Pechter wrote:

> I used to be the guy who
> at the most desperate would get Kermit over a 3 wire interface to allow
> data transfer between different systems.  Or UUCP on ms-dos...
> 
> Something about jack of all trades.

Kermit seems to be or was(?) the Swiss army knife of communications.
Or the 9-track tape ...
;-)



^ permalink raw reply	[flat|nested] 27+ messages in thread

* [COFF] 52-pin D-Sub?
  2020-02-28 22:36                   ` clemc
  2020-02-28 23:40                     ` pechter
@ 2020-02-28 23:54                     ` pechter
  1 sibling, 0 replies; 27+ messages in thread
From: pechter @ 2020-02-28 23:54 UTC (permalink / raw)


One thought I had for the 52 pin D-sub were the two 50 pin Pertec tape interface cables in some "cabinet kit" packaging for under floor.  

Saw this at Fort Monmouth Cecom on an 11/750 from a military project for early office automation on System V Unix based off of 2.x Unix work at Hanscom AFB called Lonex (if I remember the acronym). 

Bill
Sent from pechter at gmail.com
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* [COFF] 52-pin D-Sub?
  2020-02-28 22:36                   ` clemc
@ 2020-02-28 23:40                     ` pechter
  2020-02-29 16:52                       ` clemc
  2020-02-28 23:54                     ` pechter
  1 sibling, 1 reply; 27+ messages in thread
From: pechter @ 2020-02-28 23:40 UTC (permalink / raw)


Most of the RS232 spec seemed to be designed for Sync modems and their management. 

Most machines of the mini generation seemed to use either Async or Sync interfaces.  Stuff like the VT180 had a comm port that was a 8251  USART for serial comm that could be either sync or async.  I don't believe Dec had anything like that in that PDP11 or early Vax days.

Anyone care to enlighten me? 

Bill

Sent from pechter at gmail.com

-----Original Message-----
From: Clem Cole <clemc at ccc.com>
To: William Pechter <pechter at gmail.com>
Cc: Computer Old Farts Followers <coff at tuhs.org>
Sent: Fri, 28 Feb 2020 17:36
Subject: Re: [COFF] 52-pin D-Sub?

below...

On Fri, Feb 28, 2020 at 5:26 PM William Pechter <pechter at gmail.com> wrote:

> Could it be because they all started with current loop tty interfaces?
> Most of the old DEC guys started with teletypes.
>
Very possible...





>
> Having struggled with a breakout box and different mini and micro vendors
> implementations of serial ports... Ugh.  And in three-wire the use of
> Xon-Xoff varied big time.   No standard was the standard.  IIRC the IBM
> Series/1 had a different 9pin layout than the PC/AR.  Why?
>
RS-232A/B/C was DB-25 P for the DTE (terminating equiment - a.k.a.
terminal) and S for DCE (communications equipment - a.k.a. modem).  It was
standardized.  At one time, I (sadly) could quote the paragraph number....


Then in 1978 #$%^& Lear Seglier put a DB-25S on a DTE (terminal).   They
were the cheap terminal vendor and all hell broke loose.

The PC/AT used 9 pin because the back of the unit was small and -- well
there could because IBM said so ....  But at least the IBM engineers kept
to Plug and Sockets from the standard.  I did not know the Series/1 used 9
pin.   Learn something new.




>   At least DEC was reasonably consistent until they moved too the Vax
> modified RJ design.
>
Indeed - that was a huge issue - the modified RJ block -- sigh...



>
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* [COFF] 52-pin D-Sub?
  2020-02-28 22:20                   ` clemc
@ 2020-02-28 23:22                     ` pechter
  2020-02-29 13:12                       ` emu
  0 siblings, 1 reply; 27+ messages in thread
From: pechter @ 2020-02-28 23:22 UTC (permalink / raw)


The John McNamara book still seems to be around.  Great reading. 

I worked for DEC in Monmouth and Mercer counties and one night stole all the Vax 11/780 kits from DEC Holmdel.  Boy were they pissed.  However,  I had a critical outage at the FBI at Fort Monmouth with two hour response so I didn't drive an hour to my Princeton office. 8-)

I had Holmel's keys and alarm codes so I left them an IOU and headed to the site.  Holmdel was 15 minutes from the site but their techs were dedicated to telco only...  So their parts took a trip. 

The DEC folks at the labs and AT&T sites were treated like royalty compared with us regular commercial business groups.  They had the best training... newest machines...  If they found a pdp8 or 11/23 and had repair issues - - they had us called.  We saw more wierd like the Vax 11/782 that couldn't back up because it was sold without enough memory in the main (or attached cpu) to run standalone backup.  

I had to go in on Saturday to move a memory board between CPUs.  I think Field Service donated a board to RCA Semi finally.  That was a dumb machine design. 

I spent years with a lot of computer companies and RS232 interfaces were easy as long as there was only one vendor.  If you see how Pr1me or Hewlett Packard dealt with the serial ports... I used to be the guy who at the most desperate would get Kermit over a 3 wire interface to allow data transfer between different systems.  Or UUCP on ms-dos... 

Something about jack of all trades. 

Bill

Sent from pechter at gmail.com

-----Original Message-----
From: Clem Cole <clemc at ccc.com>
To: Dave Horsfall <dave at horsfall.org>
Cc: Computer Old Farts Followers <coff at tuhs.org>
Sent: Fri, 28 Feb 2020 17:21
Subject: Re: [COFF] 52-pin D-Sub?

On Fri, Feb 28, 2020 at 4:58 PM Dave Horsfall <dave at horsfall.org> wrote:

>
> Sure, but then DEC Field Circus won't touch the box.
>
That's not true.  All our UNIX systems at UCB and CMU had DEC field service
on them and we had lots of non-DEC HW, including memory, disk and disk
controllers.   Funny, the DEC knew we could swap memory chips on the
National Semiconductor memory board for the Vax.  Which we could not do
with the DEC boards, they had to be swapped.

The same was true at BTL, in fact and at Bell, there were DEC folks
on-site.  They might occasionally gripe, but we used to joke about it.  It
probably helped in all these places we had more than multiple systems and
the field offices knew better.  If we called, it was busted.



>
> Heh heh :-)  I don't think I've ever seen RS-232 used "properly" i.e.
> implementing DSR/DTR or RTS/CTS for other than flow control etc, and using
> the secondary pins as well.

Maybe you never saw a serial RJE station or I suspect a  serial line that
was fully synchronous running one of the IBM protocols.  That was sort of
where I started to learn in the late 1960s.  I saw IBM systems before I saw
the DEC ones and IBM used all the wires.  Eventually, I got a copy of the
wonderful DEC press book from John McNamara, called "Technical Aspects of
Data Communications."

Then I learned about UNIX, which came from AT&T which used all that stuff
in their modems and data communications gear.
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* [COFF] 52-pin D-Sub?
  2020-02-28 21:58                 ` dave
  2020-02-28 22:20                   ` clemc
@ 2020-02-28 22:38                   ` pechter
  1 sibling, 0 replies; 27+ messages in thread
From: pechter @ 2020-02-28 22:38 UTC (permalink / raw)


Actually Dec would take the stuff on contract in the mid to late 80s.  
They went hard on customer service retention and came up with a third party mauntenance plan on stuff like Emulex controllers, CDC976x drives... etc. 

Not sure if the Able was in the plan.  Had to do with diags and parts availability.

I have some personal experience in the area, but I don't know if I can post it... 

Too many war stories before Dec lost the war for survival. 

The view from field service was fascinating including non-mergers with AT&T around 1984 and almost an outsource of the Bell Labs data centers to DEC in. 1984.   

Bill 
Sent from pechter at gmail.com

-----Original Message-----
From: Dave Horsfall <dave at horsfall.org>
To: Computer Old Farts Followers <coff at tuhs.org>
Sent: Fri, 28 Feb 2020 16:58
Subject: Re: [COFF] 52-pin D-Sub?

On Fri, 28 Feb 2020, Clem Cole wrote:

> DZ-11 sucked... for a number of reasons, the SW issue being just part of 
> them, but they were short pinned and really did not do modems well, 
> particularly high-speed ones like the Trailblazer.  As you said, you 
> could make them work, but why bother?

We used ours for local terminals only; 8 DZ-11s on the 11/70 worked fine 
(I don't recall how fast, but probably around 2400/4800).  As I said, it 
came down to the driver.

> Unix folks figure out the best idea was to use the Able DH/DM -  
> cheaper, only one unibus slot for 16 ports (as opposed to 2 for the DZ), 
> fully wired on the DB25 end, hardware flow control and just worked 
> better in that is will DMA.  What was not to love...

Sure, but then DEC Field Circus won't touch the box.

> FWIW:  One of the guys behind DZ (who I will leave nameless) also 
> screwed up the first serial port on the Masscomp MC/500 after he left 
> DEC. I got there too late to fix it in the first version of the CPU 
> board.  So it was not fixed until I tore him a new one and educated him 
> on how RS-232 actually worked (I was the first lead for the data com 
> group as well as 1/2 the OS team).  I never quite understood why HW 
> folks often though of the serial port as '3-wires' -- sigh.

Heh heh :-)  I don't think I've ever seen RS-232 used "properly" i.e. 
implementing DSR/DTR or RTS/CTS for other than flow control etc, and using 
the secondary pins as well.

-- Dave
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* [COFF] 52-pin D-Sub?
  2020-02-28 22:26                 ` pechter
@ 2020-02-28 22:36                   ` clemc
  2020-02-28 23:40                     ` pechter
  2020-02-28 23:54                     ` pechter
  0 siblings, 2 replies; 27+ messages in thread
From: clemc @ 2020-02-28 22:36 UTC (permalink / raw)


below...

On Fri, Feb 28, 2020 at 5:26 PM William Pechter <pechter at gmail.com> wrote:

> Could it be because they all started with current loop tty interfaces?
> Most of the old DEC guys started with teletypes.
>
Very possible...





>
> Having struggled with a breakout box and different mini and micro vendors
> implementations of serial ports... Ugh.  And in three-wire the use of
> Xon-Xoff varied big time.   No standard was the standard.  IIRC the IBM
> Series/1 had a different 9pin layout than the PC/AR.  Why?
>
RS-232A/B/C was DB-25 P for the DTE (terminating equiment - a.k.a.
terminal) and S for DCE (communications equipment - a.k.a. modem).  It was
standardized.  At one time, I (sadly) could quote the paragraph number....


Then in 1978 #$%^& Lear Seglier put a DB-25S on a DTE (terminal).   They
were the cheap terminal vendor and all hell broke loose.

The PC/AT used 9 pin because the back of the unit was small and -- well
there could because IBM said so ....  But at least the IBM engineers kept
to Plug and Sockets from the standard.  I did not know the Series/1 used 9
pin.   Learn something new.




>   At least DEC was reasonably consistent until they moved too the Vax
> modified RJ design.
>
Indeed - that was a huge issue - the modified RJ block -- sigh...



>
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* [COFF] 52-pin D-Sub?
  2020-02-28 22:05                 ` drb
@ 2020-02-28 22:28                   ` clemc
  0 siblings, 0 replies; 27+ messages in thread
From: clemc @ 2020-02-28 22:28 UTC (permalink / raw)


On Fri, Feb 28, 2020 at 5:12 PM Dennis Boone <drb at msu.edu> wrote:

>  > using the secondary pins as well.
>
> Best I could tell, the major intended purpose of the secondary circuits
> was to implement autodialer, especially when those handshaking signals
> on the primary were down because there was no connection, so you
> couldn't do anything through them yet.
>
The autodialer is a separate spec.   It's ECMA RS-4xx something IIRC, I
forget the number and I'm not near my books.  That was the DN-11 from DEC
which talked to an AT&T 801 dialer.  It used RS-232C electrical signals,
but it's actually different than RS-232C (IIRC, Able called them a
'QuadraCall').

The way auto-dialing is spec'ed, is that a single dialer supports N
modems.  The Out-Band dialing stuff was an invention of Hayes who clearly
had not read the AT&T (later ECMA) spec.




>
> Was there anything else in mind during the spec process?
>
RJE stations.
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* [COFF] 52-pin D-Sub?
  2020-02-28 21:44               ` clemc
  2020-02-28 21:58                 ` dave
  2020-02-28 22:05                 ` drb
@ 2020-02-28 22:26                 ` pechter
  2020-02-28 22:36                   ` clemc
  2 siblings, 1 reply; 27+ messages in thread
From: pechter @ 2020-02-28 22:26 UTC (permalink / raw)


Could it be because they all started with current loop tty interfaces? 
Most of the old DEC guys started with teletypes.  

Having struggled with a breakout box and different mini and micro vendors implementations of serial ports... Ugh.  And in three-wire the use of Xon-Xoff varied big time.   No standard was the standard.  IIRC the IBM Series/1 had a different 9pin layout than the PC/AR.  Why?  At least DEC was reasonably consistent until they moved too the Vax modified RJ design. 

I am still amazed at the number of current loop DZ11s interfaced via 4 pin square phone jacks on a wall at the back of the machine room.   Seemed like 100 lines of VTs and Dec writers at one hospital in 1985.

As far as the DZ... One thing I saw at Dec to improve things was the Comm-iop DZ which managed the DZ from a KMC11 (IIRC).  I think it was a CSS option on PDP11s....

Bill
Sent from pechter at gmail.com

-----Original Message-----
From: Clem Cole <clemc at ccc.com>
To: Dave Horsfall <dave at horsfall.org>
Cc: Computer Old Farts Followers <coff at tuhs.org>
Sent: Fri, 28 Feb 2020 16:44
Subject: Re: [COFF] 52-pin D-Sub?

On Fri, Feb 28, 2020 at 4:28 PM Dave Horsfall <dave at horsfall.org> wrote:

> Hey, don't knock the DZ-11; if you used the right driver they worked just
> fine :-)  The trick was to disable interrupts and empty the silos every so
> often.
>
DZ-11 sucked... for a number of reasons, the SW issue being just part of
them, but they were short pinned and really did not do modems well,
particularly high-speed ones like the Trailblazer.  As you said, you could
make them work, but why bother?

Unix folks figure out the best idea was to use the Able DH/DM -  cheaper,
only one unibus slot for 16 ports (as opposed to 2 for the DZ), fully wired
on the DB25 end, hardware flow control and just worked better in that is
will DMA.  What was not to love...

On my long 'todo' list has been to work with Mark to get SIMH to properly
support the DH in his emulation.   He has some stuff in there, but last
time I checked (about a year ago) it still was not right, which is a sort
of a shame.

FWIW:  One of the guys behind DZ (who I will leave nameless) also screwed
up the first serial port on the Masscomp MC/500 after he left DEC. I got
there too late to fix it in the first version of the CPU board.  So it was
not fixed until I tore him a new one and educated him on how RS-232
actually worked (I was the first lead for the data com group as well as 1/2
the OS team).  I never quite understood why HW folks often though of the
serial port as '3-wires' -- sigh.
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* [COFF] 52-pin D-Sub?
  2020-02-28 21:58                 ` dave
@ 2020-02-28 22:20                   ` clemc
  2020-02-28 23:22                     ` pechter
  2020-02-28 22:38                   ` pechter
  1 sibling, 1 reply; 27+ messages in thread
From: clemc @ 2020-02-28 22:20 UTC (permalink / raw)


On Fri, Feb 28, 2020 at 4:58 PM Dave Horsfall <dave at horsfall.org> wrote:

>
> Sure, but then DEC Field Circus won't touch the box.
>
That's not true.  All our UNIX systems at UCB and CMU had DEC field service
on them and we had lots of non-DEC HW, including memory, disk and disk
controllers.   Funny, the DEC knew we could swap memory chips on the
National Semiconductor memory board for the Vax.  Which we could not do
with the DEC boards, they had to be swapped.

The same was true at BTL, in fact and at Bell, there were DEC folks
on-site.  They might occasionally gripe, but we used to joke about it.  It
probably helped in all these places we had more than multiple systems and
the field offices knew better.  If we called, it was busted.



>
> Heh heh :-)  I don't think I've ever seen RS-232 used "properly" i.e.
> implementing DSR/DTR or RTS/CTS for other than flow control etc, and using
> the secondary pins as well.

Maybe you never saw a serial RJE station or I suspect a  serial line that
was fully synchronous running one of the IBM protocols.  That was sort of
where I started to learn in the late 1960s.  I saw IBM systems before I saw
the DEC ones and IBM used all the wires.  Eventually, I got a copy of the
wonderful DEC press book from John McNamara, called "Technical Aspects of
Data Communications."

Then I learned about UNIX, which came from AT&T which used all that stuff
in their modems and data communications gear.
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* [COFF] 52-pin D-Sub?
  2020-02-28 21:44               ` clemc
  2020-02-28 21:58                 ` dave
@ 2020-02-28 22:05                 ` drb
  2020-02-28 22:28                   ` clemc
  2020-02-28 22:26                 ` pechter
  2 siblings, 1 reply; 27+ messages in thread
From: drb @ 2020-02-28 22:05 UTC (permalink / raw)


 > using the secondary pins as well.

Best I could tell, the major intended purpose of the secondary circuits
was to implement autodialer, especially when those handshaking signals
on the primary were down because there was no connection, so you
couldn't do anything through them yet.

Was there anything else in mind during the spec process?

De


^ permalink raw reply	[flat|nested] 27+ messages in thread

* [COFF] 52-pin D-Sub?
  2020-02-28 21:44               ` clemc
@ 2020-02-28 21:58                 ` dave
  2020-02-28 22:20                   ` clemc
  2020-02-28 22:38                   ` pechter
  2020-02-28 22:05                 ` drb
  2020-02-28 22:26                 ` pechter
  2 siblings, 2 replies; 27+ messages in thread
From: dave @ 2020-02-28 21:58 UTC (permalink / raw)


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On Fri, 28 Feb 2020, Clem Cole wrote:

> DZ-11 sucked... for a number of reasons, the SW issue being just part of 
> them, but they were short pinned and really did not do modems well, 
> particularly high-speed ones like the Trailblazer.  As you said, you 
> could make them work, but why bother?

We used ours for local terminals only; 8 DZ-11s on the 11/70 worked fine 
(I don't recall how fast, but probably around 2400/4800).  As I said, it 
came down to the driver.

> Unix folks figure out the best idea was to use the Able DH/DM -  
> cheaper, only one unibus slot for 16 ports (as opposed to 2 for the DZ), 
> fully wired on the DB25 end, hardware flow control and just worked 
> better in that is will DMA.  What was not to love...

Sure, but then DEC Field Circus won't touch the box.

> FWIW:  One of the guys behind DZ (who I will leave nameless) also 
> screwed up the first serial port on the Masscomp MC/500 after he left 
> DEC. I got there too late to fix it in the first version of the CPU 
> board.  So it was not fixed until I tore him a new one and educated him 
> on how RS-232 actually worked (I was the first lead for the data com 
> group as well as 1/2 the OS team).  I never quite understood why HW 
> folks often though of the serial port as '3-wires' -- sigh.

Heh heh :-)  I don't think I've ever seen RS-232 used "properly" i.e. 
implementing DSR/DTR or RTS/CTS for other than flow control etc, and using 
the secondary pins as well.

-- Dave


^ permalink raw reply	[flat|nested] 27+ messages in thread

* [COFF] 52-pin D-Sub?
  2020-02-28 21:28             ` dave
@ 2020-02-28 21:44               ` clemc
  2020-02-28 21:58                 ` dave
                                   ` (2 more replies)
  0 siblings, 3 replies; 27+ messages in thread
From: clemc @ 2020-02-28 21:44 UTC (permalink / raw)


On Fri, Feb 28, 2020 at 4:28 PM Dave Horsfall <dave at horsfall.org> wrote:

> Hey, don't knock the DZ-11; if you used the right driver they worked just
> fine :-)  The trick was to disable interrupts and empty the silos every so
> often.
>
DZ-11 sucked... for a number of reasons, the SW issue being just part of
them, but they were short pinned and really did not do modems well,
particularly high-speed ones like the Trailblazer.  As you said, you could
make them work, but why bother?

Unix folks figure out the best idea was to use the Able DH/DM -  cheaper,
only one unibus slot for 16 ports (as opposed to 2 for the DZ), fully wired
on the DB25 end, hardware flow control and just worked better in that is
will DMA.  What was not to love...

On my long 'todo' list has been to work with Mark to get SIMH to properly
support the DH in his emulation.   He has some stuff in there, but last
time I checked (about a year ago) it still was not right, which is a sort
of a shame.

FWIW:  One of the guys behind DZ (who I will leave nameless) also screwed
up the first serial port on the Masscomp MC/500 after he left DEC. I got
there too late to fix it in the first version of the CPU board.  So it was
not fixed until I tore him a new one and educated him on how RS-232
actually worked (I was the first lead for the data com group as well as 1/2
the OS team).  I never quite understood why HW folks often though of the
serial port as '3-wires' -- sigh.
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* [COFF] 52-pin D-Sub?
  2020-02-28 16:35           ` krewat
@ 2020-02-28 21:28             ` dave
  2020-02-28 21:44               ` clemc
  0 siblings, 1 reply; 27+ messages in thread
From: dave @ 2020-02-28 21:28 UTC (permalink / raw)


On Fri, 28 Feb 2020, Arthur Krewat wrote:

> 8250's and 16540's were horrible. Much like DZ11's, eh? ;)

Hey, don't knock the DZ-11; if you used the right driver they worked just 
fine :-)  The trick was to disable interrupts and empty the silos every so 
often.

-- Dave


^ permalink raw reply	[flat|nested] 27+ messages in thread

* [COFF] 52-pin D-Sub?
  2020-02-28 14:34           ` athornton
@ 2020-02-28 21:23             ` dave
  0 siblings, 0 replies; 27+ messages in thread
From: dave @ 2020-02-28 21:23 UTC (permalink / raw)


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On Fri, 28 Feb 2020, Adam Thornton wrote:

> A RocketPort multi-serial sounds really, really likely for an 
> astrophysics data collection instrument.  Thank you!  Mystery probably 
> solved!

I remember the RocketPort; we used to call it the OctopusPort...

> The 8250 was unbuffered or maybe had a 1 byte buffer, the 16450 had a 
> 1-byte buffer, the 16550 had a 16-byte buffer.  I remember vividly how 
> much better my life got when I got 16550 serial ports for my '386.

The 16550 series was an utter balls-up, with broken silos etc.  This is 
from http://en.wikipedia.org/wiki/16550_UART :

    The original 16550 had a bug that prevented this FIFO from being used.
    National Semiconductor later released the 16550A which corrected this
    issue. Not all manufacturers adopted this nomenclature, however,
    continuing to refer to the fixed chip as a 16550.

    According to another source, the FIFO issue was corrected only in the
    16550AF model, with the A model still being buggy. (The C and CF
    models are okay too, according to this source.) The 16550AFN model
    added DMA transfers.

You had to pay careful attention to the manufacturer and the suffix.

-- Dave


^ permalink raw reply	[flat|nested] 27+ messages in thread

* [COFF] 52-pin D-Sub?
  2020-02-28 14:11         ` clemc
  2020-02-28 14:34           ` athornton
@ 2020-02-28 16:35           ` krewat
  2020-02-28 21:28             ` dave
  1 sibling, 1 reply; 27+ messages in thread
From: krewat @ 2020-02-28 16:35 UTC (permalink / raw)


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
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On 2/28/2020 9:11 AM, Clem Cole wrote:
>
> [1] The original PC/AT used the NS8250 UART with no input buffering, 
> which went through a couple of generations, eventually begat the *550 
> version and had I think an 8 character input buffer.  But IIRC none of 
> them had hardware flow control.   I forget the # now, Moto made a nice 
> dual UART with 16 chars of input buffering, that many of us on Unix 
> workstation business used, but when we moved to BSD 386 and Linux, we 
> were stuck with PC hardware, which had a particularly hard time with 
> things like the Trailblazer  (which was the modem of choice for UUCP).
>
I ran a BBS for a few years back in the early 90's, and used a 486DX2-66 
as my "front-end" to a Sun SPARC-IPC USENET setup. Using two V.34 and 
one Worldblazer, running them at 38,400 baud, and taking advantage of 
compression, it ran 100% download, 100% upload, or a combination across 
three modems without even showing much load at all. It could have easily 
taken more if I had the physical space (and the IRQs) on the ISA bus to 
add more serial ports. Of course, the interrupt coalescing of the 
16550's helped a lot. And I don't know what the saturation point was...

That was on x86 SVR4.2 (Consensys), using a shareware 16550 driver of 
the time. The Worldblazer talked to a Trailblazer at Motorola for my 
USENET feed and used G protocol, acceleration built into the Telebits.

8250's and 16540's were horrible. Much like DZ11's, eh? ;)

art k.

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* [COFF] 52-pin D-Sub?
  2020-02-28 14:11         ` clemc
@ 2020-02-28 14:34           ` athornton
  2020-02-28 21:23             ` dave
  2020-02-28 16:35           ` krewat
  1 sibling, 1 reply; 27+ messages in thread
From: athornton @ 2020-02-28 14:34 UTC (permalink / raw)


A RocketPort multi-serial sounds really, really likely for an astrophysics
data collection instrument.  Thank you!  Mystery probably solved!

The 8250 was unbuffered or maybe had a 1 byte buffer, the 16450 had a
1-byte buffer, the 16550 had a 16-byte buffer.  I remember vividly how much
better my life got when I got 16550 serial ports for my '386.

Adam

On Fri, Feb 28, 2020 at 7:12 AM Clem Cole <clemc at ccc.com> wrote:

> Adam/Dave,
>
> For whatever's it's worth, in PC/AT ISA bus times, at least one of the
> serial port vendors (RocketPort was the vendor IIRC), used a DB-52P
> connector, that connected to an interesting 'tail' which had 8 DB25P
> connected to the DB25-S at the other end.   This allowed 6 data conductors
> (RCV/XMT/RTS/CTS/CD/DTR) * 8 ports, plus 6 grounds which again IIRC they
> interspersed among the remaining 6 ground pins.
>
> What I remember is that it was this specific board that was one of only a
> handful serial boards[1] that could run UNIX properly and hang Trailblazer
> modems off of it because they not only fully pinned, but they had
> single-chip custom USART with a good bit of buffering and hardware-based
> RTS/CTS flow control.  I think I may still have one somewhere, as I saw the
> cable for it when I was looking for something else over the Christmas
> holidays.
>
> [1] The original PC/AT used the NS8250 UART with no input buffering, which
> went through a couple of generations, eventually begat the *550 version and
> had I think an 8 character input buffer.  But IIRC none of them had
> hardware flow control.   I forget the # now, Moto made a nice dual UART
> with 16 chars of input buffering, that many of us on Unix workstation
> business used, but when we moved to BSD 386 and Linux, we were stuck with
> PC hardware, which had a particularly hard time with things like the
> Trailblazer  (which was the modem of choice for UUCP).
>
> Clem
> _______________________________________________
> COFF mailing list
> COFF at minnie.tuhs.org
> https://minnie.tuhs.org/cgi-bin/mailman/listinfo/coff
>
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* [COFF] 52-pin D-Sub?
  2020-02-28  4:18       ` dave
@ 2020-02-28 14:11         ` clemc
  2020-02-28 14:34           ` athornton
  2020-02-28 16:35           ` krewat
  0 siblings, 2 replies; 27+ messages in thread
From: clemc @ 2020-02-28 14:11 UTC (permalink / raw)


Adam/Dave,

For whatever's it's worth, in PC/AT ISA bus times, at least one of the
serial port vendors (RocketPort was the vendor IIRC), used a DB-52P
connector, that connected to an interesting 'tail' which had 8 DB25P
connected to the DB25-S at the other end.   This allowed 6 data conductors
(RCV/XMT/RTS/CTS/CD/DTR) * 8 ports, plus 6 grounds which again IIRC they
interspersed among the remaining 6 ground pins.

What I remember is that it was this specific board that was one of only a
handful serial boards[1] that could run UNIX properly and hang Trailblazer
modems off of it because they not only fully pinned, but they had
single-chip custom USART with a good bit of buffering and hardware-based
RTS/CTS flow control.  I think I may still have one somewhere, as I saw the
cable for it when I was looking for something else over the Christmas
holidays.

[1] The original PC/AT used the NS8250 UART with no input buffering, which
went through a couple of generations, eventually begat the *550 version and
had I think an 8 character input buffer.  But IIRC none of them had
hardware flow control.   I forget the # now, Moto made a nice dual UART
with 16 chars of input buffering, that many of us on Unix workstation
business used, but when we moved to BSD 386 and Linux, we were stuck with
PC hardware, which had a particularly hard time with things like the
Trailblazer  (which was the modem of choice for UUCP).

Clem
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* [COFF] 52-pin D-Sub?
  2020-02-28  4:12     ` dave
@ 2020-02-28  4:18       ` dave
  2020-02-28 14:11         ` clemc
  0 siblings, 1 reply; 27+ messages in thread
From: dave @ 2020-02-28  4:18 UTC (permalink / raw)


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On Fri, 28 Feb 2020, Dave Horsfall wrote:

>> Huh.  New to me too, but Digikey links to the datasheets, and they 
>> really do mean DB.They go up to DD100.  They are called “double 
>> density”.
>
> No; the "B" in "DB" means B-sized e.g. the size of a DB-25 connector. 
> This is a common mistake e.g. a "DB-9" (sic) would be a 25-pin sized 
> connector holding just 9 pins (it's really a "DE-9") with godnoze-what 
> spacing.

Oops - I misread what you wrote; apologies...

-- Dave


^ permalink raw reply	[flat|nested] 27+ messages in thread

* [COFF] 52-pin D-Sub?
  2020-02-28  1:37   ` stewart
  2020-02-28  2:12     ` athornton
@ 2020-02-28  4:12     ` dave
  2020-02-28  4:18       ` dave
  1 sibling, 1 reply; 27+ messages in thread
From: dave @ 2020-02-28  4:12 UTC (permalink / raw)


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
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On Thu, 27 Feb 2020, Lawrence Stewart wrote:

> Huh.  New to me too, but Digikey links to the datasheets, and they 
> really do mean DB.They go up to DD100.  They are called “double 
> density”.

No; the "B" in "DB" means B-sized e.g. the size of a DB-25 connector. 
This is a common mistake e.g. a "DB-9" (sic) would be a 25-pin sized 
connector holding just 9 pins (it's really a "DE-9") with godnoze-what 
spacing.

Believe it or not there is a convention for it:

     http://en.wikipedia.org/wiki/D-subminiature

Yes, it's one of my gripes...

-- Dave


^ permalink raw reply	[flat|nested] 27+ messages in thread

* [COFF] 52-pin D-Sub?
  2020-02-28  1:37   ` stewart
@ 2020-02-28  2:12     ` athornton
  2020-02-28  4:12     ` dave
  1 sibling, 0 replies; 27+ messages in thread
From: athornton @ 2020-02-28  2:12 UTC (permalink / raw)


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
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Yeah, 0.075" pin centers, does appear to be the ITT Cannon part.

Now what experiment used them, and _why_ (I mean, surely 68-pin SCSI would
have done the trick as well and been muuuuuuch cheaper), I don't know.

Adam

On Thu, Feb 27, 2020 at 6:37 PM Lawrence Stewart <stewart at serissa.com>
wrote:

> Huh.  New to me too, but Digikey links to the datasheets, and they really
> do mean DB.
> They go up to DD100.  They are called “double density”.
>
> This reminds me of the circa 1990 “HIPPI” interface, or high performance
> parallel interface.  They typically ran at 50 MB/sec.  The connectors were
> two-row 100-pin D style.  See
> http://www.elpeus.com/scsi-cables/100pin-scsi-cable-hippi/3m-100pin-male-to-100pin-male-scsi-cable-hippi/ for
> example.
>
> We used these cables and connectors on the first Alpha machines at Digital
> to connect the 3Max front end processor to the ECL based Alpha
> Demonstration Units, although the protocol was different.  The connector
> was about the biggest that would fit on a TurboChannel I/O card.
>
>
> On 2020, Feb 27, at 7:04 PM, Dave Horsfall <dave at horsfall.org> wrote:
>
> On Thu, 27 Feb 2020, Adam Thornton wrote:
>
> I recently have pulled out of the trash a plugboard with a male and a
> female D-Sub 52 connector.  3 rows of pins, 17-18-17.  I took the
> connectors off the board: there's nothing back there, so this thing only
> ever existed so you could plug the random cable you found into it and its
> friends to see what the cable fit.
>
>
> That would be something like a DD-52P (certainly not a DB-52P!).
>
> I can't find much evidence that a 52-pin D-Sub ever existed.
>
>
> Well, Digikey seem to have them:
>
>
> http://www.digikey.com/product-detail/en/itt-cannon-llc/2DB-52P/2DB-52P-ND/4734668
>
> No photo, though...
>
> -- Dave_______________________________________________
> COFF mailing list
> COFF at minnie.tuhs.org
> https://minnie.tuhs.org/cgi-bin/mailman/listinfo/coff
>
>
> _______________________________________________
> COFF mailing list
> COFF at minnie.tuhs.org
> https://minnie.tuhs.org/cgi-bin/mailman/listinfo/coff
>
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* [COFF] 52-pin D-Sub?
  2020-02-28  0:04 ` dave
@ 2020-02-28  1:37   ` stewart
  2020-02-28  2:12     ` athornton
  2020-02-28  4:12     ` dave
  0 siblings, 2 replies; 27+ messages in thread
From: stewart @ 2020-02-28  1:37 UTC (permalink / raw)


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Huh.  New to me too, but Digikey links to the datasheets, and they really do mean DB.
They go up to DD100.  They are called “double density”.

This reminds me of the circa 1990 “HIPPI” interface, or high performance parallel interface.  They typically ran at 50 MB/sec.  The connectors were two-row 100-pin D style.  See http://www.elpeus.com/scsi-cables/100pin-scsi-cable-hippi/3m-100pin-male-to-100pin-male-scsi-cable-hippi/ <http://www.elpeus.com/scsi-cables/100pin-scsi-cable-hippi/3m-100pin-male-to-100pin-male-scsi-cable-hippi/> for example.

We used these cables and connectors on the first Alpha machines at Digital to connect the 3Max front end processor to the ECL based Alpha Demonstration Units, although the protocol was different.  The connector was about the biggest that would fit on a TurboChannel I/O card.


> On 2020, Feb 27, at 7:04 PM, Dave Horsfall <dave at horsfall.org> wrote:
> 
> On Thu, 27 Feb 2020, Adam Thornton wrote:
> 
>> I recently have pulled out of the trash a plugboard with a male and a female D-Sub 52 connector.  3 rows of pins, 17-18-17.  I took the connectors off the board: there's nothing back there, so this thing only ever existed so you could plug the random cable you found into it and its friends to see what the cable fit.
> 
> That would be something like a DD-52P (certainly not a DB-52P!).
> 
>> I can't find much evidence that a 52-pin D-Sub ever existed.
> 
> Well, Digikey seem to have them:
> 
>    http://www.digikey.com/product-detail/en/itt-cannon-llc/2DB-52P/2DB-52P-ND/4734668
> 
> No photo, though...
> 
> -- Dave_______________________________________________
> COFF mailing list
> COFF at minnie.tuhs.org
> https://minnie.tuhs.org/cgi-bin/mailman/listinfo/coff

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* [COFF] 52-pin D-Sub?
  2020-02-27 23:37 athornton
@ 2020-02-28  0:04 ` dave
  2020-02-28  1:37   ` stewart
  0 siblings, 1 reply; 27+ messages in thread
From: dave @ 2020-02-28  0:04 UTC (permalink / raw)


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
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On Thu, 27 Feb 2020, Adam Thornton wrote:

> I recently have pulled out of the trash a plugboard with a male and a 
> female D-Sub 52 connector.  3 rows of pins, 17-18-17.  I took the 
> connectors off the board: there's nothing back there, so this thing only 
> ever existed so you could plug the random cable you found into it and 
> its friends to see what the cable fit.

That would be something like a DD-52P (certainly not a DB-52P!).

> I can't find much evidence that a 52-pin D-Sub ever existed.

Well, Digikey seem to have them:

     http://www.digikey.com/product-detail/en/itt-cannon-llc/2DB-52P/2DB-52P-ND/4734668

No photo, though...

-- Dave


^ permalink raw reply	[flat|nested] 27+ messages in thread

* [COFF] 52-pin D-Sub?
@ 2020-02-27 23:37 athornton
  2020-02-28  0:04 ` dave
  0 siblings, 1 reply; 27+ messages in thread
From: athornton @ 2020-02-27 23:37 UTC (permalink / raw)


I work at an astronomy facility.  I get to do some fun dumpster diving.

I recently have pulled out of the trash a plugboard with a male and a
female D-Sub 52 connector.  3 rows of pins, 17-18-17.  I took the
connectors off the board: there's nothing back there, so this thing only
ever existed so you could plug the random cable you found into it and its
friends to see what the cable fit.

I can't find much evidence that a 52-pin D-Sub ever existed.

Is this just Yet Another Physics Experiment thing where, hey, if your
instrument already costs three million dollars, what's a couple of grand
for machining custom connectors?  Or was it once a thing?

(also posting to cc-talk)

Adam
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end of thread, other threads:[~2020-02-29 16:52 UTC | newest]

Thread overview: 27+ messages (download: mbox.gz / follow: Atom feed)
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2020-02-29  9:59 [COFF] 52-pin D-Sub? rudi.j.blom
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2020-02-27 23:37 athornton
2020-02-28  0:04 ` dave
2020-02-28  1:37   ` stewart
2020-02-28  2:12     ` athornton
2020-02-28  4:12     ` dave
2020-02-28  4:18       ` dave
2020-02-28 14:11         ` clemc
2020-02-28 14:34           ` athornton
2020-02-28 21:23             ` dave
2020-02-28 16:35           ` krewat
2020-02-28 21:28             ` dave
2020-02-28 21:44               ` clemc
2020-02-28 21:58                 ` dave
2020-02-28 22:20                   ` clemc
2020-02-28 23:22                     ` pechter
2020-02-29 13:12                       ` emu
2020-02-29 15:45                         ` krewat
2020-02-29 15:49                           ` clemc
2020-02-28 22:38                   ` pechter
2020-02-28 22:05                 ` drb
2020-02-28 22:28                   ` clemc
2020-02-28 22:26                 ` pechter
2020-02-28 22:36                   ` clemc
2020-02-28 23:40                     ` pechter
2020-02-29 16:52                       ` clemc
2020-02-28 23:54                     ` pechter

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