[GreenKeys] [External] Re: Teletype DRPE tuned reed mechanism

[Eric Moore]

Here is the video of the BRPE in operation. My first attempt to send this
to the list was blocked as spam.

https://youtu.be/-aZl8rMT8Aw

Thank you for everyone's help in finding info on the device.

If I get around to building better control electronics to drive the device
at full speed I will let the list know.

If anyone knows where I could find the original control electronics for a
BRPE, a CX type reader, or a DRPE, please let me know as I would love to
play with and record them for posterity.

-Eric


On Mon, Dec 28, 2020 at 10:14 AM Jones, Douglas W <douglas-w-jones at uiowa.edu>
wrote:

> From: Eric Moore [mooreericnyc at gmail.com] -- Monday, December 28, 2020
> 9:32 AM
>
> > Do you happen to know what device was used for punching 8 level paper
> tape prior to 1954?
>
> I don't thik 8-level tape was used by anyone back then.  All the 1950s
> computers used 6-level codes.  Word sizes were multiples of 6 bits, with 36
> bit words being dominant for large computers, with small computers being
> made in 12, 18 and 24 bit words.
>
> The DEC PDP-8 from 1965 was the first computer DEC made where ASCII was
> the standard code used internally and the Model 33 ASR tty as the default
> console I/O device.  All earlier DEC machines used 6-bit character sets,
> and they used Flexowriters for console devices.
>
> IBM's System 360, also 1965, was their first machine with 32-bit words and
> an 8-bit byte (except some research machines).  They developed EBCDIC, and
> 8-bit character code, for that machine.  All their earlier offerings used
> BCD, a 6-bit character code.  Both EBCDIC and BCD were encodings of the
> 12-bit Hollerith code on punched cards.  The logic to compress 12 bits to 6
> or 8 bits was trivial and directly explains the odd gaps in the assignment
> of BCD and EBCDIC codes.
>
> The LGP-30 computer, one of the best selling very small computers,
> introduced in 1957, used a 6-bit code on its Flexowriters.
>
> ASCII was developed by Teletype Corp (with strong input from the computer
> industry) in 1964.  It was, of course, a natural extension of Teletype
> corp's 5-level Baudot code.  The Flexowriter Programmatic line also used
> 8-level tape; I think the Flexowriter SPD was the first of their machines
> to go 8-level.
>
>        Doug Jones
>        jones at cs.uiowa.edu
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