15 Dec
2015
15 Dec
'15
12:54 a.m.
- intention was to rip all this out and convert it to
a full I/O serial terminal, using an Arduino-based setup
that Lawrence Wilkinson has already built and tested:
https://www.flickr.com/photos/ljw/sets/72157632841492802/with/9201494189/
Looks very nice! Is there documentation for it somewhere? I also have a Selectric
(unfortunately it's located distant from me at the moment so I can't provide
particulars) that I worked on interfacing to a micro in the mid-70's. I was using a
MC6800 in my recollection, but I don't believe that I ever achieved operational
status. Presumably I was working from an article in one of the hobbyist magazines of the
era. I would have guessed Byte, but that doesn't seem to be the case based on recent
search. Any hints from folks on what magazine/article that might have been?
The Selectric wasn't one of the curvy(ier) office models; I recall it being a rather
boxy affair with plenty of right-angles on the housing and a medium shade of blue --
presumably "IBM Blue". Rather utilitarian in design. Even *more* utilitarian
than this one:
http://www.covingtoninnovations.com/selectric/100112-Selectric-in-situ.jpg
It included a full keyboard. I'm not sure anymore whether it operated in local-mode
or was set up as two separate devices and therefore needed to be connected up to a remote
controller to get local copy. It might have been a rehoused Selectric mechanism in a
third-party enclosure and the IBM-like color a red herring. My recollection is that it
was longer front-to-back; presumably the rearward extension housed the additional
electronics. I have absolutely no idea how I acquired it. No luck finding a matching
photo online as yet.
I believe that the Selectric came configured for remote operation, but presumably using an
EBCDIC-based data stream. I vaguely recall a DB-50 connector, but it's been an
awfully long time ...
Does this description sound familiar to anyone?
-----
paul
15 Dec
15 Dec
10:27 a.m.
On Dec 15, 2015, at 12:54 AM, Paul Birkel <pbirkel
at gmail.com> wrote:
...
I believe that the Selectric came configured for remote operation, but presumably using
an EBCDIC-based data stream. I vaguely recall a DB-50 connector, but it's been an
awfully long time ...
Does this description sound familiar to anyone?
For a while, RSTS/E supported 2741 terminals, which are Selectric terminals with a UART
interface. It wasn't EBCDIC -- instead, it had one of several possible conversion
tables. I forgot the number of bits per character. Also, the speed used was peculiar:
134.5 bits per second. 2741 support was dropped at some point; I think V7 has it but it
disappeared by V9 if not sooner.
paul
12:42 p.m.
On 2015-12-15 11:27 AM, Paul Koning wrote:
They used a 6 bit code with odd parity so some of the code sheets refer
to it as a 7 bit code because they include the "C" parity bit.
Paul.
On Dec 15,
2015, at 12:54 AM, Paul Birkel <pbirkel at gmail.com> wrote:
...
I believe that the Selectric came configured for remote operation, but presumably using
an EBCDIC-based data stream. I vaguely recall a DB-50 connector, but it's been an
awfully long time ...
Does this description sound familiar to anyone?
For a while, RSTS/E supported 2741
terminals, which are Selectric terminals with a UART interface. It wasn't EBCDIC --
instead, it had one of several possible conversion tables. I forgot the number of bits
per character. Also, the speed used was peculiar: 134.5 bits per second. 2741 support
was dropped at some point; I think V7 has it but it disappeared by V9 if not sooner.
paul
3:05 p.m.
On Wed, Dec 16, 2015 at 4:27 AM, Paul Koning <paulkoning at comcast.net> wrote:
That IS interesting. I have two 2741s - one mostly working, needs a
little mechanical fettling, one untested but believed needing work. It
seems I could bring up a pre-V7 RSTS and incant the right runes at it
and the 2741 would Just Work.
What other OSes might have native 2741 support built in, anyone know?
Mike
http://www.corestore.org
'No greater love hath a man than he lay down his life for his brother.
Not for millions, not for glory, not for fame.
For one person, in the dark, where no one will ever know or see.'
On Dec 15, 2015, at 12:54 AM, Paul Birkel
<pbirkel at gmail.com> wrote:
...
I believe that the Selectric came configured for remote operation, but presumably using
an EBCDIC-based data stream. I vaguely recall a DB-50 connector, but it's been an
awfully long time ...
Does this description sound familiar to anyone?
For a while, RSTS/E supported 2741 terminals, which are Selectric terminals with a UART
interface. It wasn't EBCDIC -- instead, it had one of several possible conversion
tables. I forgot the number of bits per character. Also, the speed used was peculiar:
134.5 bits per second. 2741 support was dropped at some point; I think V7 has it but it
disappeared by V9 if not sooner. 
3:26 p.m.
On 12/15/15 12:05 PM, Mike Ross wrote:
What other OSes might have native 2741 support built
in, anyone know?
I would expect that IBM mainframe OS's would support it
(especially
older ones). The issue there would be getting the 2741 connected up.
I have a DECWriter III with the APL option on it. I'd really like to
get that hooked up to MVT running APL\360! Of course, I'd *really* like
to have a 2741 with an APL typeball for that! ;-)
TTFN - Guy
4:41 p.m.
On Wed, Dec 16, 2015 at 9:26 AM, Guy Sotomayor <ggs at shiresoft.com> wrote:
On 12/15/15 12:05 PM, Mike Ross wrote:
Well IBM of course - I was thinking more other DEC OS's and various
flavors of Unix...
Mike
http://www.corestore.org
'No greater love hath a man than he lay down his life for his brother.
Not for millions, not for glory, not for fame.
For one person, in the dark, where no one will ever know or see.'
What other OSes might have native 2741 support built in, anyone know?
I would expect that IBM mainframe OS's would support it (especially older
ones). The issue there would be getting the 2741 connected up. 
8:21 p.m.
DEC made a Selectric interface called LT33 or something, consisting of
a general purpose parallel card for a PDP-8/E coupled to a small
chassis with a bunch of solenoid drivers and stuff for the Selectric.
I think it was a CSS product, so I doubt it was supported by any
official OS.
I have three or four of the things, plus docs.
--
Will
On Tue, Dec 15, 2015 at 4:41 PM, Mike Ross <tmfdmike at gmail.com> wrote:
On Wed, Dec 16, 2015 at 9:26 AM, Guy Sotomayor <ggs
at shiresoft.com> wrote:
On 12/15/15 12:05 PM, Mike Ross wrote:
Well IBM of course - I was thinking more other DEC OS's and various
flavors of Unix...
Mike
http://www.corestore.org
'No greater love hath a man than he lay down his life for his brother.
Not for millions, not for glory, not for fame.
For one person, in the dark, where no one will ever know or see.'
What other OSes might have native 2741 support built in, anyone know?
I would expect that IBM mainframe OS's would support it (especially older
ones). The issue there would be getting the 2741 connected up. 
9:13 p.m.
On 15 December 2015 at 20:21, William Donzelli <wdonzelli at gmail.com> wrote:
DEC made a Selectric interface called LT33 or
something, consisting of
If I recall my DEC naming correctly, the LT33 is *not* for
the
Selectric. It (and the corresponding LT35) are the modifications made
to private line Model 33 (and Model 35, respectively) ASR Teletype
machines to make them work as the console teleprinter (and have the
reader work under computer control).
Then again, they could have reused the name "LT33" but that would get
confusing.
Regards,
Christian
--
Christian M. Gauger-Cosgrove
STCKON08DS0
Contact information available upon request.
10:19 p.m.
Like I said "or something". I could not recall that the time.
A quick look shows that it is actually LT73.
--
Will
On Tue, Dec 15, 2015 at 9:13 PM, Christian Gauger-Cosgrove
<captainkirk359 at gmail.com> wrote:
On 15 December 2015 at 20:21, William Donzelli
<wdonzelli at gmail.com> wrote:
DEC made a Selectric interface called LT33 or
something, consisting of
If I recall my DEC naming correctly, the LT33 is *not* for
the
Selectric. It (and the corresponding LT35) are the modifications made
to private line Model 33 (and Model 35, respectively) ASR Teletype
machines to make them work as the console teleprinter (and have the
reader work under computer control).
Then again, they could have reused the name "LT33" but that would get
confusing.
Regards,
Christian
--
Christian M. Gauger-Cosgrove
STCKON08DS0
Contact information available upon request. 
4:50 p.m.
-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Guy
Sotomayor
Sent: 15 December 2015 20:26
To: General Discussion: On-Topic and Off-Topic Posts
<cctalk at classiccmp.org>
Subject: Re: IBM Selectric-based Terminals
On 12/15/15 12:05 PM, Mike Ross wrote:
Hercules now has support for 2741 via Telnet
What other OSes might have native 2741 support
built in, anyone know?
I would expect that IBM mainframe OS's would support it
(especially older
ones). The issue there would be getting the 2741 connected up.
I have a DECWriter III with the APL option on it.
I'd really like to get that
hooked up to MVT running APL\360! Of course, I'd *really* like to have a
2741 with an APL typeball for that! ;-)
Again 2708 with 2741 supported..
TTFN - Guy
Dave
G4UGM
9:10 p.m.
On Wed, Dec 16, 2015 at 10:50 AM, Dave Wade <dave.g4ugm at gmail.com> wrote:
That is cool - but requires a host OS that supports 2741 login so you
can then telnet to Herc... does Linux have 2741 support? I have vague
memories of tweaking ?termcap? to support something odd I once shoved
into a serial port - but not 2741 odd!
What would be considerably cooler is if you could dedicate a serial
port to Herc - plug in the 2741; switch it on; get an IBM login prompt
*directly*.
Mike
http://www.corestore.org
'No greater love hath a man than he lay down his life for his brother.
Not for millions, not for glory, not for fame.
For one person, in the dark, where no one will ever know or see.'
-----Original
Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Guy
Sotomayor
Sent: 15 December 2015 20:26
To: General Discussion: On-Topic and Off-Topic Posts
<cctalk at classiccmp.org>
Subject: Re: IBM Selectric-based Terminals
On 12/15/15 12:05 PM, Mike Ross wrote:
Hercules now has support for 2741 via Telnet What other OSes might have native 2741 support
built in, anyone know?
I would expect that IBM mainframe OS's would support it
(especially older
ones). The issue there would be getting the 2741 connected up.
7:25 p.m.
On 15 December 2015 at 15:05, Mike Ross <tmfdmike at gmail.com> wrote:
What other OSes might have native 2741 support built
in, anyone know?
I might be completely wrong, but I think some of the early UNIX
versions might "speak" 2741. But I'm not sure. Perhaps a sufficiently
"vintage" RSX-11 might as well?
Of course like Guy Sotomayor said, IBM mainframe operating systems can
speak 2741. OS/360 can, and I'm pretty sure so can MVS and VM/370 but
my IBM knowledge is somewhat limited.
Also, I really want one of those 2741s. Selectrics that can do I/O are
*bleep*ing cool.
Regards,
Christian
--
Christian M. Gauger-Cosgrove
STCKON08DS0
Contact information available upon request.
16 Dec
16 Dec
2:39 p.m.
From: Christian Gauger-Cosgrove
Sent: Tuesday, December 15, 2015 4:25 PM
Also, I really want one of those 2741s. Selectrics
that can do I/O are
*bleep*ing cool.
2741s are OK. I much preferred the 2740, though. We had those at the
Computer-Assisted Instruction Laboratory at the UTexas School of Education
(Student job, autumn 1969-autumn 1970), but only 2741s at Ohio State.
On the 2741, ETX is tied to the Return key. That made correcting a class
of errors in Coursewriter III much harder: Incorrectly inserted labels could
not be removed by the author, but only by a systems programmer editing the
file on disk.
On the 2740, there was a bank of 6 buttons to the upper right of the Selectric
keyboard. I only remember 3 labels, because the other 3 didn't do anything
special under Coursewriter III or APL\360, but the important ones were EOT,
ETX, and EOB. With judicious use of these, newlines could be inserted into the
entered text at will, allowing for the selection of labels surrounded by empty
lines. It also allowed for security by obscurity: The supervisor password on
the Coursewriter III system was 0x4040404040404015, which could not be entered
on a 2741.
Ah, the Good Old Days(TM)...
Rich
Rich Alderson
Vintage Computing Sr. Systems Engineer
Living Computer Museum
2245 1st Avenue S
Seattle, WA 98134
mailto:RichA at LivingComputerMuseum.org
http://www.LivingComputerMuseum.org/
15 Dec
15 Dec
10:37 a.m.
On 2015-12-15 1:54 AM, Paul Birkel wrote:
Looks very nice! Is there documentation for it
somewhere? I also have
a Selectric (unfortunately it's located distant from me at the moment
so I can't provide particulars) that I worked on interfacing to a
micro in the mid-70's. I was using a MC6800 in my recollection, but I
don't believe that I ever achieved operational status. Presumably I
was working from an article in one of the hobbyist magazines of the
era. I would have guessed Byte, but that doesn't seem to be the case
based on recent search. Any hints from folks on what magazine/article
that might have been? The Selectric wasn't one of the curvy(ier)
office models; I recall it being a rather boxy affair with plenty of
right-angles on the housing and a medium shade of blue -- presumably
"IBM Blue". Rather utilitarian in design. Even *more* utilitarian than
this one:
http://www.covingtoninnovations.com/selectric/100112-Selectric-in-situ.jpg
It included a full keyboard. I'm not sure anymore whether it operated
in local-mode or was set up as two separate devices and therefore
needed to be connected up to a remote controller to get local copy. It
might have been a rehoused Selectric mechanism in a third-party
enclosure and the IBM-like color a red herring. My recollection is
that it was longer front-to-back; presumably the rearward extension
housed the additional electronics. I have absolutely no idea how I
acquired it. No luck finding a matching photo online as yet. I believe
that the Selectric came configured for remote operation, but
presumably using an EBCDIC-based data stream. I vaguely recall a DB-50
connector, but it's been an awfully long time ... Does this
description sound familiar to anyone? ----- paul
The selectric pictured in your
link above is a standard Office Products
(OP) Selectric II. Some of the selectric terminals where in a enclosure
that was very similar. The 2741, 2741 and 1980 I/O units where in a
similar case but where sunk into a cutout in the desk they where mounted
in. The 2970 mod 8 and mod 11 banking terminals where in larger boxy
enclosures to accommodate extra hardware that was hung on them for
banking applications. The 3735 programmable terminal had a Selectric
I/O II attached that looked just like an OP Selectric except for some
indicator lights and the big cable exiting out the back. None of the
Selectric terminals I worked on had any electronics inside, except arc
suppression diodes, all of the electronics where housed in an attached
control unit.
The selectric terminals I worked on where mostly used for banking teller
station and finance company terminals. The coding of the data was more
geared towards the position of the characters on the type ball with 4
bits for rotate (+1, +1, +2, and -5) and two bits for tilt (+1 and +2)
and there where also code points allocated to function such as tab, CR +
LF, space, shift up and shift down. The relation of the code point to
the graphic printed depended on the layout of the type ball being used,
and they where not always the same as the OP selectric. The type ball
used by the banks for instance, was laid out so that no two numbers
where adjacent to each other on the type ball to lessen the risk of
printing an incorrect number.
Paul.
3142
days inactive
3143
days old
13 comments
9 participants
participants (9)
-
captainkirk359＠gmail.com -
dave.g4ugm＠gmail.com -
ggs＠shiresoft.com -
paulkoning＠comcast.net -
pbirkel＠gmail.com -
phb.hfx＠gmail.com -
RichA＠LivingComputerMuseum.org -
tmfdmike＠gmail.com -
wdonzelli＠gmail.com