Acoustic Coupled Modems & papertape....

From: Derek Peschel <>
Date: Wed Mar 10 18:54:24 1999

Frank McConnell wrote:
> Arfon Gryffydd <> wrote:
> > How about the specifications for paper-tape (i.e. hole spacing, paper
> > width, etc.)?

> Hole spacing is 0.1". 8-level tape is 1" wide, with 3 holes, then a
> smaller-diameter sprocket hole, then 5 holes. There also exist 7- and
> 5-level tapes which are simply narrower (3+1+4, 3+1+2), and maybe also
> a six-level tape but I don't know what used it.

I think that 6-level tape was popular in the publishing industry for
controlling Linotypes. They extended one of the 5-bit codes by adding an
extra bit for upper/lower case. Of course that's different from the
figure/letter shift mechanism that was already in the code (which some
people call upper/lower case). HAVING BOOKS IN ALL CAPS WOULDN'T SELL VERY

I've seen a Teletype with a 6-bit character set but I haven't looked at the
type bars to see what specific characters the thing prints. (It doesn't
work -- some bars need to be realigned or remade -- so I couldn't just try
it out.)

-- Derek
Received on Wed Mar 10 1999 - 18:54:24 GMT

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