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* [TUHS] Teletype
@ 2014-08-15 18:04 Brian Zick
       [not found] ` <99C03A20-7BC3-44CA-946D-6CFD56B9346F@orthanc.ca>
                   ` (2 more replies)
  0 siblings, 3 replies; 24+ messages in thread
From: Brian Zick @ 2014-08-15 18:04 UTC (permalink / raw)


Howdy folks -

So I'm mostly a lurker here and love the history and the way things used to
be done. But being born in '91 I pretty much missed all of it, although I
did grow up with 80s machines in the house.

There is one thing that I would love to do, and may seem a curious thing to
most, but I think about it from time to time, and it's enticing. But I'm
not sure where one would get started.

Would it still be possible today for someone like me to go out, and find an
old teletype terminal (an old ASR or DECwriter or something), set up a
phone line and modem and get a roll of paper, and then actually use it to
connect to other computers?

I know it's not really practical today - but is it possible?

Brian Zick
zickzickzick.com

     .:/
  ,,///;,   ,;/
 o:::::::;;///
>::::::::;;\\\
  ''\\\\\'' ';\
     \



On Fri, Aug 1, 2014 at 8:13 AM, Andy Kosela <akosela at andykosela.com> wrote:

>
>
> On Friday, August 1, 2014, Dario Niedermann <dnied at tiscali.it> wrote:
>
>> Tim Newsham <tim.newsham at gmail.com> wrote:
>>
>> > just for fun, you might want to run your
>> > ancient unix in simh using this terminal:
>> > https://github.com/Swordifish90/cool-old-term
>>
>> Cool! I've been waiting for ages for something like the Cathode terminal
>> emulator
>> to appear on Linux too. Cathode is Mac OS X only, unfortunately.
>> Homepage:   http://devio.us/~ndr/
>> Gopherhole: gopher://retro-net.org/1/dnied/
>>
>>
> I still prefer my old Digital VT terminal though.  Nothing will beat CRT
> screen when it comes to low resolution text-only mode.
>
> --Andy
>
> _______________________________________________
> TUHS mailing list
> TUHS at minnie.tuhs.org
> https://minnie.tuhs.org/mailman/listinfo/tuhs
>
>
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^ permalink raw reply	[flat|nested] 24+ messages in thread
* [TUHS] Teletype
@ 2014-08-15 21:47 Noel Chiappa
  2014-08-15 21:53 ` Warner Losh
  2014-08-15 22:01 ` John Cowan
  0 siblings, 2 replies; 24+ messages in thread
From: Noel Chiappa @ 2014-08-15 21:47 UTC (permalink / raw)


    > From: Brian Zick <brian at zickzickzick.com>

    > Would it still be possible today for someone like me to go out, and
    > find an old teletype terminal (an old ASR or DECwriter or something),
    > set up a phone line and modem and get a roll of paper, and then
    > actually use it to connect to other computers?

Well, although I used ASR33's for two years (attached to an 11/20 running
RSTS :-), it was a long time ago (I was 15/16 :-), and they aren't something
I _really_ know about, but ... Here are some issues you need to watch out for:


First, I think most Teletypes used what is called '20mA current loop' serial
line electrical interface standard (although some of the later ones could use
'EIA' - the now-usual, although fast disappearing, serial line electrical
interface standard). They are logically (i.e. at the framing level) the same,
but the voltages/etc are different.

The only Teletype I see listed (in a _very_ quick search, don't take this for
gospel) that used EIA is the Model 37.  So if you get a Teletype Model 33 or
35, and want to plug it into a computer, either the computer is going to have
to have an _old_ serial line interface (e.g. DL-11A/C, on a PDP-11), or you're
going to have to locate a 20mA/EIA converter (I've never seen such a thing,
but I expect they existed).

And if you want to plug it into a modem... all modems I ever heard of are EIA
(at least, the ones you could plug terminals into - e.g. in most PC modem
cards, the serial interface is entirely internal to the card).


Second, most of those Teletypes were 110 baud (mechanical hardware
limitation).

So that means that first, if you plug into a computer, your serial interface
has to be able to go that slow. Second, if you're dialing up, you need to find
a dial-up port that supports 110 baud. (I would be seriously amazed if any are
left...)


Of course, if you go with a DecWriter, some of these issues go away, but be
careful: some older DecWriters were 20mA too, and the speeds were almost as
slow on many (probably 300 baud, but I don't know much about DecWriters).
Sorry to be so much cold water, but...

As for finding one... I suggest eBay. There's a broken ASR33 there at the
moment - if you're _really_ serious, might be worth buying as a parts
source. But if you wait, I'm pretty sure one will eventually float by...

	Noel



^ permalink raw reply	[flat|nested] 24+ messages in thread
* [TUHS] Teletype
@ 2014-08-15 21:55 ckeck
  0 siblings, 0 replies; 24+ messages in thread
From: ckeck @ 2014-08-15 21:55 UTC (permalink / raw)


Rats :( :( :(

Did they have power supplies, and did they still work?

On Fri, 15 Aug 2014, Clem Cole wrote:

> Date: Fri, 15 Aug 2014 17:07:28 -0400
> From: Clem Cole <clemc at ccc.com>
> To: Brian Zick <brian at zickzickzick.com>
> Cc: "tuhs at minnie.tuhs.org" <tuhs at minnie.tuhs.org>
> Subject: Re: [TUHS] Teletype
[...]
>
> Funny, just this AM, I put into the the electronics recycling box at work 4
> telebit "Worldblazer" modems and a POTS line emulator (and a bunch of other
> old junk).   I've been clean out my basement and I knew I would never use
> those again.
>


---------------------------------------------
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^ permalink raw reply	[flat|nested] 24+ messages in thread
* [TUHS] Teletype
@ 2014-08-16 14:35 Noel Chiappa
  0 siblings, 0 replies; 24+ messages in thread
From: Noel Chiappa @ 2014-08-16 14:35 UTC (permalink / raw)


    > From: John Cowan <cowan at mercury.ccil.org>

    >> if you're dialing up, you need to find a dial-up port that supports
    >> 110 baud.

    > I dialed up The World's local dialup line for my area, and heard a
    > large variety of tones including Bell 103-compatible FSK, which is 300
    > baud. I suspect that anything that can do Bell 103 can fall back to
    > Bell 101, which was 110 baud.

There are two more things one needs to have for the port to support 110: i)
the serial interface needs to support 110 (even if the modem is integrated
with the serial hardware on one board, the serial hardware might not do 110),
and ii) the software needs to be willing to go 110.

I don't know anything about how contemporary dial-up ports work, so maybe
there's some side-channel from the modem to the interface which allows the
software to find out directly what speed the modem is using. However, 'back in
the day' with multi-speed ports, there was no such mechanism (the RS-232
interface spec didn't provide for speed indication), and one had to hit BREAK
and the serial line device driver would see that, and try the next speed in a
list. You can still see this in the big table of terminal types in getty.c,
e.g.:

  /* table '0'-1-2 300,150,110 */

which tried 300, 150, 110. So if the software isn't looking for 110...

	Noel



^ permalink raw reply	[flat|nested] 24+ messages in thread
* [TUHS] Teletype
@ 2014-08-17 17:33 Noel Chiappa
  0 siblings, 0 replies; 24+ messages in thread
From: Noel Chiappa @ 2014-08-17 17:33 UTC (permalink / raw)


    > From: Ernesto Celis <ecelis at sdf.org>

    > I own an USRobotics modem which I've been thinking about connect to the
    > home server and use it to dial in to get acces to my shell

Just out of curiousity, what are you going to dial in _with_? :-)

	Noel



^ permalink raw reply	[flat|nested] 24+ messages in thread
* [TUHS] Teletype
@ 2014-08-18 13:56 Noel Chiappa
  0 siblings, 0 replies; 24+ messages in thread
From: Noel Chiappa @ 2014-08-18 13:56 UTC (permalink / raw)


    > From: Brian Zick <brian at zickzickzick.com>

    > The fun of trying to do something in this now novel way is really
    > great. I was thinking I might try using it for my email. The
    > news-ticker idea also seems great

I suspect you'll find that the charm wears off pretty quickly, if you try and
use it for Real Stuff, day in, and day out. There's a reason this technology
is not used any more! :-)

    > I'm really excited that this not only seems possible but nearly in
    > reach.

I share you enthusiasm for the fun of computer archaeology. (Thanks to Milo,
I now have an 11/84 that I'm in the process of trying to get up.) Good luck!

	Noel



^ permalink raw reply	[flat|nested] 24+ messages in thread

end of thread, other threads:[~2014-09-15 19:51 UTC | newest]

Thread overview: 24+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-08-15 18:04 [TUHS] Teletype Brian Zick
     [not found] ` <99C03A20-7BC3-44CA-946D-6CFD56B9346F@orthanc.ca>
2014-08-15 18:52   ` Brian Zick
2014-08-15 19:05     ` Ed Skinner
2014-08-15 19:13       ` Lyndon Nerenberg
2014-08-15 21:07     ` Clem Cole
2014-08-15 21:23       ` Hoskins, Matthew E.
2014-08-18  5:54       ` Brian Zick
2014-08-16 10:25     ` Dario Niedermann
2014-08-15 19:08 ` John Cowan
2014-08-15 19:16   ` Lyndon Nerenberg
2014-08-16 20:42   ` Ernesto Celis
     [not found] ` <CAEvOwxW=G+g3dtSGaN=P7QmovgOygfANxacmcUo9Devn6v6B1Q@mail.g mail.com>
2014-09-15 15:13   ` John Foust
2014-09-15 19:38     ` Dave Horsfall
2014-09-15 19:51     ` Cory Smelosky
2014-08-15 21:47 Noel Chiappa
2014-08-15 21:53 ` Warner Losh
2014-08-15 22:01 ` John Cowan
2014-08-16  1:56   ` Lyndon Nerenberg
2014-08-16  2:12     ` Lyndon Nerenberg
2014-08-16 21:28       ` Ronald Natalie
2014-08-15 21:55 ckeck
2014-08-16 14:35 Noel Chiappa
2014-08-17 17:33 Noel Chiappa
2014-08-18 13:56 Noel Chiappa

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