Volunteer Information Exchange
Sharing what we know with those we know
Volume 4 Number 2
February 3, 2014
Contribute To The VIE
CHM's New Blog
You undoubtedly know that there is class of
new docents in training. While they are still
getting their collective feet on the ground, they
are beginning to contribute in many ways. One
way is that they are doing book reports of
many of the recommended books in our
docent library. One of those book reviews is
included this month. Written by Dave Levish,
about Colossus, it is on page 2. Thanks Dave.
We will be including more of those book
reviews in future issues.
Jeff Katz writes on his experiences with the
Quipu in his article “Who Invented the Quipu?
And When?”
Please give us your stories, experiences and
knowledge.
Jim Strickland
[email protected]
“No matter how slick the demo is in rehearsal,
when you do it in front of a live audience, the
probability of a flawless presentation is
inversely proportional to the number of people
watching, raised to the power of the amount of
money involved.”
(Mark Gibbs)
The VIE Cumulative Index is stored at:
http://s3data.computerhistory.org.s3.amazon
aws.com/chmedu/VIE000_Cumulative_Topic_Index.pdf
CONTENTS
Contribute to the VIE
1
CHM Blog
1
First Computer Bug
1
Colossus: Book Review
2
Who Invented the Quipu? And Why?
5
IBM 1620 “Plotter”
6
Coming Events
6
Recent CHM Blog Entries
Kirsten Tashev keeps us up-to-date on our CHM Blog. Recent
Entries are:
• 1/27 Guest blog post by Jonathan Rotenberg, founder of the
Boston Computer Society, as he shares with us his memories
of the night Steve Jobs presented the Macintosh to the BCS.
Also included for the first time in 30 years, the video of that
night.
• 1/23 Curator, Chris Garcia, a kind of “yesterday’s tomorrows”
piece on Computer Games
• 1/13 guest blogger, Lisa Nakamura, Professor at the
University of Maryland. Prof. Nakamura conducted research in
the CHM Archives this past year and has an interesting
perspective to share.
First Computer Bug
Bud Warashima sent an article from the Wall Street Journal by
etymologist, Ben Zimmer. It was occasioned by Google's
recent animated doodle in tribute to Grace Hopper's finding of
the moth/bug in the Harvard Mark II in 1947. We have edited
and excerpted that article.
As we know she taped the moth in her logbook and noted,
"First actual case of bug being found."
But Zimmer points out that this was not the first use of the term
“bug.” That appears to be another Edison invention. "Bug"
appeared in Edison's notebooks as early as 1876 to describe
problems in his systems. "Awful lot of bugs still," read one
notebook entry about a plan for incandescent lighting. He also
developed what he called a "bug trap" to catch relay errors in
his early telegraph system.
Within a couple of decades, Edison's usage of "bug" became
common enough to enter dictionaries. "A fault in the working of
a quadruplex telegraph or in any electrical apparatus," was how
Funk and Wagnalls' Standard Dictionary of the English
Language defined it in 1893.
So the term was known, and used by the staff of the Mark I the
precursor to the moth-ridden Mark II. A 1944 logbook entry read,
"Ran test problem. Mr. Durfee from I.B.M. [sic] was here to help
us find 'bugs." As for "debugging," the Oxford English
Dictionary traces the term back to 1945.
So Hopper was undoubtedly joking when she said, "first actual
case" of a computer bug being found. She was humorously
playing off a known usage in technical circles.
As Zimmer says, “While we celebrate the achievements of a
pioneering woman in computing, let's not perpetuate an
etymological story that's a little buggy.”
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the styles, level of technical detail, emphasis and overall
tone frequently change from chapter to chapter. The
reader must be able to deal with the inevitable British
English in the book. German and French terms are also
used.
The book is 462 pages and consists of 26 chapters and
12 appendices divided in to 7 sections as follows:
1. Bletchley Park and the Attack on Tunny. This is a
very brief introduction to cryptography, British code
breaking through the beginning of World War II, a
description of Tunny and a high-level description of how
Tunny was broken.
2. Colossus. A description of the Colossi, the steps
taken to build them and the effort to build a working
replica in the 21st century.
3. The Newmanry. The Newmanry was the section at
Bletchley Park charged with building and operating the
Colossi and other machines that decrypted the Tunny
intercepts.
4. The Testery. The Testery was the section at
Bletchley Park responsible for the initial manual
decryption of Tunny intercepts. When the Colossi were
installed, the Testery was responsible for determining
Tunny cam settings that were changed regularly
(initially monthly, later daily).
5. T. H. Flowers’s Laboratory at Dollis Hill. Dollis
Hill was the location where the Colossi were designed
and where several of the systems, including the first,
were built.
6. Sturgeon, The Fish That Got Away. Another
German encryption machine used during WW II.
7. Technical Appendices – To Dig Deeper. This
section contains backing material for the other sections,
such as a time line of Tunny and Colossus
developments, some of the mathematics behind the
Tunny machine and the cryptanalysis done to break it
and sources for references. This section is over 100
pages.
There is much overlap and even some conflicting
information between the sections. For instance, most
information states that 10 Colossus machines were built,
but occasionally 11 is the number used. It is unclear if
the total of 11 includes the replica built in the 2000’s or if
the number is in error.
Colossus: A Book Review
DAVE LEVISH
The Secrets of Bletchley Park’s Codebreaking
Computers
B. Jack Copeland and others (many others)
Summary:
Colossus was the name of a series of computers
(collectively called Colossi) that were built during World
War II to decode German “Tunny” messages. The first
Colossus was functioning in December 1943, about two
years before ENIAC and greatly improved Bletchley
Park’s productivity. At the end of the war, most of the
Colossi were destroyed. Their very existence was kept
secret until the mid 1970s and much information about
the Colossus project remained classified until the mid
1990s.
German Lorenz SZ40 (“Tunny”) machine
The Tunny Machine
Unlike the more famous Enigma machine, the Lorenz
SZ40 encryption machine and its later developments
collectively called “Tunny” by the British, was an
attachment to a teletype. Plain text was input to a
teletype (aka teleprinter) either by a normal keyboard or
by means of a paper tape. The Tunny machine was in
between the teletype and the communication equipment,
typically a radio. The encrypted output from Tunny was
Baudot-Murray code sent the same way as unencrypted
teletype communications. The process was reversed for
This is generally believed to be the last (10th)
Colossus built
Overview of the Book:
“Colossus” is written by a total of 31 different authors
with the largest contribution by university professor Jack
Copeland, who is listed as the primary author. Whilst it
is obvious that some editing was done for consistency,
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reception. Thus, those sending and receiving the
message never saw the encrypted text.
Tunny was controlled by 12 wheels which could be
altered via cams and an initial starting position. There
were three distinct functions for the wheels. The first set
of 5 wheels was called Chi wheels that moved each time
a character was encoded. The second set of 5 wheels
was called Psi wheels that sometimes moved and
sometimes did not. The final set of 2 wheels, called
motor wheels, controlled whether or not the Psi wheels
moved. The original character was encrypted by
XORing the output of the Chi and Psi wheels with the
original character. This allowed the encryption to be
reversible, i.e., when the setting matched and input
encrypted character generated its original value. Baudot
code is a 5-bit code which is why there were sets of 5
wheels.
The major weakness of Tunny was that the way the Psi
wheels operated. The Psi wheels moved in unison and,
due to the action of the motor wheels, might not move at
all, causing their contribution to the output encrypted
character could remain unchanged for several
characters. This introduced a statistically significant
irregularity to the encrypted text that could be used to
determine the cam setting of the wheels and their initial
positions.
Max Newman was the project manager for this effort. He
realized that the machines used to decrypt Enigma
messages would not be sufficient for Tunny traffic and
that a new approach was needed.
A machine eventually called “Heath Robinson” was built
to test whether the initial wheel settings could be
determined by machine. Heath’s logic was primarily
relay based, though some tubes were used for higher
speed where necessary. Heath repeatedly read two
tapes at varying offsets to determine the most likely
settings of the Tunny wheels through statistical analysis
of the data read. Though it proved the task could be
done, Heath had many problems. It was too slow, too
unreliable and error prone (two identical runs could
produce different results).
An electrical engineer named Thomas (Tommy) Flowers
that worked designing electronic phone switching
equipment for the Royal Post Office (which also was
responsible for the telephone system) was brought in to
work on the problem. Between February and December
1943, his team designed and built the first Colossus
system. Although it was designed with the primary
purpose of determining the settings of the Tunny wheels
for a given intercepted message, it was designed to be
more general purpose than that so that new decryption
techniques could be incorporated as they were
developed.
Colossus I could process an input encrypted message at
5,000 characters per second (many passes were
needed), used 1600 vacuum tubes and was programmed
through the use of patch cords and switches. Its logic
unit could perform 100 Boolean operations on the input
stream and set counters as each character was read.
Output results were printed on an automatic typewriter.
Colossus was, by every measure, the world’s first
electronic computer.
Colossus II was a much improved version of Colossus I.
It contained 2400 vacuum tubes, processed encrypted
messages at nearly 25,000 characters per second (125
times faster than “Heath Robinson”) and was the world’s
first electronic parallel computer.
In all, ten Colossus computers were built – all of them
differing to some degree – by the end of the war. When
the war was over, eight of the Colossi were destroyed
with some of the parts being sent to various universities
after they were altered to the point that their original
function could not be determined. The remaining Colossi
were transferred to the U.K.’s GCHQ . The last Colossus
was destroyed in 1960.
The Tunny traffic that the Colossi decrypted consisted
primarily of messages between the highest level German
commands. Messages decrypted by the Colossi
contributed to the defeat for the Germans by the
Russians at the battle of Kursk (the beginning of the end
on the Eastern Front) and to the decision to launch the
D-Day invasion. It has been estimated by multiple
Colossus
Diagram of how Lorenz SZ40 (Tunny)
encryption works
The Tunny machine code was broken by several flashes
of brilliant insight. Although the intercepted messages
could be decrypted by a well defined set of operations, it
was quickly realized that decryption of non-trivial
messages could take hundreds of years except in those
cases where usage errors by the Germans simplified
matters. This led to efforts to “mechanise” decryption of
the messages as had been done for Enigma messages.
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sources that Colossus decrypts shortened the European
war by as much as two years.
Importance in computer history
Colossus I was functioning in December 1943, about two
Key People
years before ENIAC which is usually regarded as the first
Tommy Flowers – The architect of Colossus. He already electronic computer. ENIAC was announced February
had experience designing large telephone exchanges
14, 1946 and was presumably operating a short time
that used 3000 to 4000 vacuum tubes for switching
before that. Colossus II was the first parallel computer.
purposes which made designing Colossus a natural fit.
Though most of the original Colossus machines were
He was considered one of the, if not the, world’s leading destroyed and their existence was kept secret for 30
authority on vacuum tube based electronic equipment
years, Colossus influenced the early British computers.
design.
Alan Turing, aided by the knowledge that Colossus had
Max Newman – The project manager at Bletchley Park
been built using vacuum tubes and worked, went on to
for Colossus. Max Newman’s section was responsible
design the ACE system. A stripped-down version of this
for the procurement and operation of Colossus and other was implemented as Pilot ACE which was the world’s
equipment used to break the German Tunny machine.
fastest computer for a few years. ACE led to the British
Before the war, Max was a professor at Cambridge
MOSAIC and the American Bendix G-15 computers.
University. Among his students was Alan Turing. Max
Max Newman (along with a number of others what
was intrigued by Alan Turing’s 1936 paper about
worked at Bletchley Park) went to the University of
universal computing machinery and this has been
Manchester. Max was well aware that the technology in
credited as an influence in his decision to proceed with
Colossus could be used to create a stored program
Colossus.
computer. He was instrumental in the construction of the
Alan Turing – A well known mathematician and
Manchester SSEM a.k.a. “Baby” computer, which is one
cryptographer at Bletchley Park. Alan’s 1936 paper on
of the first stored program computers. This led directly to
universal computing machinery is one of the
the Feranti Mk 1, one of the first commercially available
cornerstones of computer science. Some of Alan’s work computers.
on decryption and his work in building machines to speed
Additional sources of information and interesting
decryption of Enigma intercepts influenced the work on
facts
Colossus. In particular, his “Bombe” machine
The Colossus computers were primarily operated by
popularized the idea of mechanized decryption. Some
women. These women were mostly in the Royal Navy
books and articles erroneously credit Alan Turing with
and known informally as Wrens (From Women’s Royal
designing Colossus. His involvement was at most
Navy Service or WRNS).
peripheral, though the fact that Colossus was built and
operated successfully no doubt contributed to his
Colossus was designed with the tubes in a horizontal
architecture of the later ACE system.
orientation to aid with heat dissipation. It was contained
in 8 racks in two rows, about 90 inches high, not
Important Dates
including the tape reader. Power consumption was
• December 1942 – Bletchley Park decides to
about 5 kW.
proceed with “mechanized” breaking of Tunny
The punched tape containing the encrypted message
intercepts
• February 1943 – Tommy Flowers submits his initial was used as the source of clock pulses for the Colossus
proposal for Colossus, which is immediately approved machine. The machine could run up to about 3 times
faster, but the tape would tend break at over 5,000 CPS.
• June 1943 – The “Heath Robinson” device begins
The message tape being decrypted moved at about 30
its initial testing
miles per hour.
• December 8, 1943 – Colossus I is operating at
Dollis Hill laboratories
Colossus used bi-quinary (bi-qui) to represent decimal
• February 5, 1944 – Colossus I is operational at
digits. A pair of tubes, one with 5 states and one with 2
Bletchley Park
states, was used for each decimal digit. This is roughly
similar to the representation used by an abacus and
• June 1, 1944 – The much improved Colossus II is
used less tubes than binary (which was considered).
operational at Bletchley Park
• April 1945 – Colossus X is operational at Bletchley Times were kept for Colossus runs. Typical times for
Park
determining the initial Tunny wheel settings for messages
• Sometime in 1960 – Colossus X, the last surviving
were 15 to 30 minutes, depending on the length of the
Colossus system, is turned off and destroyed
message and the actual setting values.
Colossus architect Tommy Flowers said of Colossus: “I
don't think they understood very clearly what I was
proposing until they actually had the machine."
4
Colossus could be “single stepped” for hardware
diagnostic purposes and to debug programming. This
was an intentional part of the original design.
The logic panel was set to determine what results were
interesting enough to be printed (typically very few).
Colossus was designed to handle interrupts, primarily to
deal with times when the output typewriter could not
keep up with the results being generated.
There is a working replica of a later model Colossus at
the Bletchley Park Museum.
Colossus could theoretically be programmed to do
decimal multiplication, but the necessary operations
would not complete within a single clock cycle.
• Use of interrupt mechanism (to prevent overloading
the printer)
• Use of higher-level description of the program
(short-hand notation, sort of like assembler)
• Optical reading of paper tape
• Use of shift registers
Web Sites
http://www.alanturing.net/turing_archive/pages/Referenc
e%20Articles/BriefHistofComp.html#Col
(Very brief description of Colossus in the context of what
led to and flowed from it)
http://www.alanturing.net/tunny_report/
(The General Report on Tunny - the German
Cryptographic system Colossus was used against.
General Report on Tunny is the source of most
declassified information that exists on Colossus.)
http://www.codesandciphers.org.uk/lorenz/rebuild.htm
(The Colossus rebuild project at Bletchley Park Museum)
http://www.codesandciphers.or.uk
(Additional information on Colossus, Lorenz (Tunny), and
simulators)
The following are generally regarded to be
computing “firsts” for Colossus
• Application of logic controlled by an alterable
program (emphasis in original)
• Use of clock-syncing pulse sent to a large block of
logic (emphasis in original)
• Parallel processing
Who Invented the Quipu? And When?
Jeff Katz
Occasionally on a tour a visitor will inquire about the
(replica) Quipu Inca knotted string memory/accounting
device we have on display in the storage gallery. The
conventional wisdom is that this complex item was used
by the Incas to record and remember important
information, possibly also to keep track of which citizens
owed what taxes. While there are several scholarly
efforts to divine how the Quipu was actually used, no
User's Manuals exist. The Incas had no written
language, so the knowledge was simply passed on, and
disappeared with the demise of the Incas at the time of
the Spanish conquistadors. Not understanding the
Quipus, and fearing what they might represent, the
conquistadors destroyed as many as they could find, and
killed the Incan elders who used them. A few hundred
original Quipus are known to exist, most in very poor
condition. They are, after all, only string, unlikely to hold
up very well over hundreds of years.
During a recent visit to Lake Titicaca in Bolivia, I was
privileged to visit a pre-Inca region, the ruins of the
Tiwanaku people, near the southern shore of the lake.
The Tiwanaku people lived in the high Andes around the
sacred lake from approximately 1500 BC until
approximately 1200 AD, and left evidence of a
sophisticated culture. The evidence suggests they were
especially adept at astronomical timekeeping,
architecture and building, agriculture and social order.
Current theories hold that just about the time they died
out in what is now Bolivia, possibly due to severe long
term drought and associated crop failure, the Incas
appeared in what is now Peru, hundreds of miles to the
north, as a fully-formed and sophisticated society with no
apparent evolutionary origins, and adept at astronomical
timekeeping, architecture and building, agriculture and
social order. Thus it's likely that the Peruvian Incas, who
were extant from around 1200 AD until the early 1500s,
were actually just a later manifestation of the migrated
Bolivian Tiwanaku people.
So what has this interesting history to do with the Quipu?
Adjacent to the Tiwanaku ruins in Bolivia is a recently
established museum that collects and displays artifacts
recovered from the ruins. Among those artifacts is a
particular piece of pottery, which has been dated to
around 400 AD, 800 years before the Incas emerged in
Peru, bearing artwork which depicts a tribal elder or
shaman extending his arm horizontally outward to his
side. Dangling from the arm is a series of knotted strings,
clearly an early version of a Quipu.
Unfortunately I was not permitted to photograph the
artifact. But on the following page is a copy of the image
of our replica Quipu, taken from the CHM website.
When I returned home I did a little on-line research on
Quipus, and turned up some interesting articles written
by an archaeology scholar. They include a list of
reference books and papers, some of which attempt to
describe potential uses and meanings of the various
string colors and knots. Even a form of binary coding of
the knots. And I was astonished to read that the oldest
known original Quipu dates from about 4600 years ago,
recently discovered at the ruins of the ancient civilization
at Caral, on the west coast of Peru. If that archaeological
dating can be trusted it makes the Quipu one of the
5
planet’s earliest forms of record keeping, only surpassed
by the cuneiform writing on clay tablets in Mesopotamia.
If you want to learn more, check: one or more of these
links:
http://archaeology.about.com/od/qterms/qt/quipu.htm
http://archaeology.about.com/od/ancientwriting/a/caralqui
pu.htm
http://archaeology.about.com/od/americanancientwriting/
a/khipucode.htm
Now when I have a visitor interested in the Inca Quipu, I
might have to point out that the device probably actually
predates the Incas by more than three thousand years!
Making it by far the oldest storage-and-retrieval
technology in our exhibits.
IBM 1620 “Plotter”
JIM STRICKLAND
I had a visitor recently, a former IBM marketing representative, who
had at one time been the salesman on the General Motors Proving
Ground in Michigan, He said that that customer had once had an
IBM 1620 – the small scientific computer from the 1960's. The 1620
used an IBM Model B typewriter as a console and sometimes input
output device.
They worked with IBM to develop an RPQ (Request for Price
Quotation ) for special type bars for the typewriter. Those special
type bars had various configurations of dots replacing many of the
characters.
With the dots, engineers were able to produce a plot of the
performance of cars being tested at the proving grounds--an
inexpensive, special purpose graphic “plotter.”
Please contribute to the
Computer History Museum
Volunteer Information Exchange
Share your stories, your interesting
facts (and factoids) and your
knowledge
Send them to Jim Strickland
([email protected])
Coming Events (Click for details)
Date
Day
Time
Event
Feb 06
Thur.
6:00 PM Member Reception
7:00 – 8:30 Program
Regis McKenna in Conversation with John Markoff
Feb 18
Tues.
6:00 PM Member Reception
7:00 – 8:30 Program
Cisco's Padmasree Warrior in Conversation with NPR's Laura
Sydell
Feb 20
Thurs. 6:00 – 9:00 PM
Mar 04
Tues.
6:00 PM Member Reception
7:00 – 8:30 Program
MLB (Major League Baseball) Advanced Media's Robert A.
Bowman in conversation with Museum CEO John Hollar
Mar 12
Wed.
2:30 Check-in
3:00 – 4:30Program
Technion's President Peretz Lavie in conversation with Museum
CEO John Hollar
Mar. 27
Thur.
6:00 PM Member Reception
7:00 – 8:30 Program
The Art & Technology of Cirque du Soleil
April 10
Thur.
6:00 PM Member Reception
7:00 – 8:00 Program
Game Changers: Sony Computer Entertainment’s Shuhei
Yoshida in conversation with Mark Cerny
NextGen Advisory Board Presents
Ninja Innovation and Startup Culture
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