In article hM67g.1131$Zf3.73@trndny01, HFguy wrote:
Grimly Curmudgeon wrote:

I fully agree that in some conditions a Morse tone will get through where
voice is an unintelligble mush, if heard at all, but apart from prisoners
tapping out messages on pipes its days as an *essential* comms tool are
pretty much over.

How do you send Morse code by tapping on a pipe when all you can send is
a 'dit'?

They don't. They use a counting code where the alphabet is represented
as a 5x5 or 6x6 (for cyrillic) matrix and then they use a count for
row and column. It was described in Koestler's "Darkness at Noon", a novel
about the Stalinist Purges, but I've read that a 5x5 version is used in the
west. Unless you're a US Airman in a North Vietnamese POW prison, they
used Morse using a tap/scrape for dot/dash.

Mark Zenier
Googleproofaddress(account:mzenier provider:eskimo domain:com)

Mark Zenier wrote:
In article hM67g.1131$Zf3.73@trndny01, HFguy wrote:

Grimly Curmudgeon wrote:

I fully agree that in some conditions a Morse tone will get through where
voice is an unintelligble mush, if heard at all, but apart from prisoners
tapping out messages on pipes its days as an *essential* comms tool are
pretty much over.

How do you send Morse code by tapping on a pipe when all you can send is
a 'dit'?


They don't. They use a counting code where the alphabet is represented
as a 5x5 or 6x6 (for cyrillic) matrix and then they use a count for
row and column. It was described in Koestler's "Darkness at Noon", a novel
about the Stalinist Purges, but I've read that a 5x5 version is used in the
west. Unless you're a US Airman in a North Vietnamese POW prison, they
used Morse using a tap/scrape for dot/dash.

Mark Zenier
Googleproofaddress(account:mzenier provider:eskimo domain:com)

Does the book say how the new prisoners learned about the code matrix if
they couldn't talk to the other prisoners? Maybe they passed around a
diagram of the matrix.

In article tLV7g.5107$re6.1672@trndny04, HFguy wrote:
Mark Zenier wrote:
In article hM67g.1131$Zf3.73@trndny01, HFguy wrote:
....
How do you send Morse code by tapping on a pipe when all you can send is
a 'dit'?

They don't. They use a counting code where the alphabet is represented
as a 5x5 or 6x6 (for cyrillic) matrix and then they use a count for
row and column. It was described in Koestler's "Darkness at Noon", a novel
about the Stalinist Purges, but I've read that a 5x5 version is used in the
west. Unless you're a US Airman in a North Vietnamese POW prison, they
used Morse using a tap/scrape for dot/dash.

Does the book say how the new prisoners learned about the code matrix if
they couldn't talk to the other prisoners? Maybe they passed around a
diagram of the matrix.

It's prison folklore, not something complicated. A verbal description
wouldn't take much time. Most probably, it was scratched on the wall
of the cell.

Dig, dig. There's a couple of pages on it in "The Codebreakers" by
David Kahn, in the chapter on Russian Codes and Codebreaking. It
stated that experienced senders could get 10-15 words a minute. The
example given for the 5x5 Latin alphabet combined i and j into one.

Mark Zenier
Googleproofaddress(account:mzenier provider:eskimo domain:com)