[GreenKeys] FTGH - M28 LARP1 multi-magnet reperf

[Nick England]

Thanks. I figured it might be useful in an Navy 82B1 system which I have
studied a bit. But that system seems to depend on 28RT units handling the
incoming line to 200wpm speed change. And vice-versa on the outgoing line.

I have a 28RT for 60/75/100 but without a time machine I figure getting
200wpm equipment is unlikely.

Cheers
Nick

On Friday, September 30, 2016, Jim Haynes <jhhaynes at earthlink.net> wrote:

> The main use of the LARP was in fully automatic store-and-forward message
> switching systems, such as Western Union's Plan 55 used by the Air Force in
> the late 1950s - early 1960s.  In one form of such systems messages are
> received on reperforator tape.  Each reperforator tape feeds directly into
> an associated tape transmitter.  There the message directing codes are
> read and interpreted, and then the tape transmitter is connected to a
> "cross office" reperforator associated with the outgoing line.  The
> message is sent across the office and perforated a second time, where
> it then feeds a tape transmitter that transmits to the selected
> destination.  If the cross-office circuit is busy when a message comes
> in then the message has to wait at the incoming-side tape reader until
> the circuit is free.
>
> It is a principle of these systems that you want the cross-office
> transmission to be faster than the incoming lines.  This way you hope
> to find the cross-office circuit non-busy when it is needed.  So the
> incoming side tape reader and the cross-office reperforator may be
> operated at 200 wpm for that reason.  The W.U. Plan 55 system used
> electronic transmitting and receiving distributors to achieve 200 wpm
> cross-office transmission; and then the character punched was compared
> with the character read to detect any failure in the reperforator or
> its driver circuits.  Older W.U. systems transmitted characters cross-
> office in parallel to achieve higher speed than the transmitting and
> receiving distributors of the day could handle.  Which meant that the
> cross-office circuit had to switch about nine wires for the bits of
> the character plus various control signals.
>
> There was some minor use of the LARP for other applications where a
> high speed punch was wanted but not badly enough to justify the
> 1050 wpm BRPE.  Or applications where the information was already
> in parallel form so it would have been extra trouble to convert it
> to serial for a conventional reperforator.
>
>
>
>

-- 
Nick England K4NYW
www.navy-radio.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/greenkeys/attachments/20160930/9894cb7e/attachment.html>