[GreenKeys] Teletype Highspeed (>100 wpm) Equipment Question

[Jack]

The DX reader actually "ripped" into the holes.  NY Tel. used them to
read 5 level
tapes into the monstrous Teletype 2510 "COMDAT" video terminal. Once
the info
was updated by an operator on the 10-inch TV tube screen, she would
then send the data to a Model
35 ROTR that had an 8-to-5 level in the bottom that in turn sent
the into to Model 15's or 28's at 75 wpm. What a clunky operation
that was! The 8 level tapes were saved as a record copy.

The DX readers would never stay in alignment and tapes were regularly
shredded....

Jack K0TTY



-----Original Message-----
From: greenkeys-bounces at mailman.qth.net
[mailto:greenkeys-bounces at mailman.qth.net] On Behalf Of Jim Haynes
Sent: Sunday, September 02, 2012 5:10 PM
To: NNN7DXB at aol.com
Cc: greenkeys at mailman.qth.net
Subject: Re: [GreenKeys] Teletype Highspeed (>100 wpm) Equipment
Question

Teletype had some experimental photo tape readers, but never produced
any.
Photo readers are capable of much higher speeds than anything Teletype
needed.  They were popular with computers for that reason.

There are problems with photo readers.  If you shine the light through
the holes, then you have trouble reading yellow oiled tape because the
light will shine through the tape almost as well as through the holes.
So you see black tape used with that kind of reader.  Others depended
on reflecting light through the holes with a mirror, which had some of
the same problems and also could not read Mylar aluminized tape at all
since it is mirror-shiny.  Another variety depends on diffusely
reflected light, so Mylar reflects too well.

Teletype also wanted to be able to stop the reader on a character.
That's hard with the really fast readers.

The CX was essentially a fast version of a typical Teletype reader.
Feeler pins that are released toward the tape by a cam and actuating
contacts, then pulling the pins back down to advance the tape feed
wheel.  The final reader I'm aware of, the DX, had contact wires that
rode on the tape, making contact as they dipped into the holes.  The
feed mechanism used as escapement.  One model, for Dataspeed Type 4,
was reversible.


jhhaynes at earthlink dot 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

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html