The story of Colossus started around 80 years ago as top secret. After 50 years or so, the cloak of secrecy cracked a little bit, but very grudgingly. It has been gradually unfolding further over the years - the latest revelations appearing in January 2024. Following are some snippets from various sources that provide some insights into what we know about Colossus, The initial idea by Tommy Flowers to build something electronic to replace the slow electro-mechanical equipment being used at that time It's design and implementation by Tommy Flowers towards the end of World War II, An eventual historic "rebuild" by Tony Sale at Bletchley Park as the secrecy cloak started to fall away half a century later in the mid-1990's, And now in 2024 after 80 years - more pictures have been released. The start of the saga is documented in the 2nd paragraph of this progress report in early 1943 -

The British were using electro-mechanical machines (lots of mechanical rotating shafts with electrical "wiper" contacts creating electrical circuits triggering relays etc.). All these moving parts were not only relatively slow, they brought with them reliability problems which slowed everything down even further. An enginer on loan from the Post Office Research Labs in London (Tommy Flowers) had an idea (see 2nd paragraph in above document flagged with a red bracket) - which was reported by his boss (Max Newman - a later founding pillar of Computer Science) to the commander of the code-breaking organization at Bletchley Park just North of London. This one paragraph - buried in a routine status report written by a Government bureaucrat, represents a pivotal event in the history of WWII and the development of the computer (IMHO). And when you think about it - the development of mankind. Man initially developed the wheel and the lever (and their eventual successors) to amplify his muscle power. Man now developed an electronic computing engine to amplify his brain power - a spark that ignited a veritable brush-fire of successive improvements that have changed the world radically over the last eight decades..

In the early 1990's, some 50 years later, Tony Sale who had retired from the British Government's GCHQ Organization (logical successor to the code-breakers of Bletchley Park) had put together a replica of Colossus. This was doubly ingenious, because only ten of these machines had ever been built during the war, and on Churchill's direct orders eight of them (together with all technical documentation) were destroyed - and the remaining two kept available for use to decode messages from other countries (who didn't know this technology had been compromised) during "the cold war". These last two were then also destroyed ("No piece bigger than a man's fist to survive" - Chrchills explicit instruction). It was around the time of this final demolition that I was enrolled in a small pioneering class of apprentices being instructed in the nuts and bolts of what would eventualy become known as "Computer Science". The instructor was a semi-retitred former Post Office Engineer - named Tommy Flowers. His name was unremarkable, and we had no idea about his background - it was still a secret...

Tony Sale's rebuild of Colossus did not proceed smoothly. He was a volunteer at the Museum in Bletchley Park at the time, and the newly installed Executive Director did not respond well to the "nuisance activities" of this "amateur" and at one time even banned him from the premises - she had no idea of what it was all about. She just wanted a well-run tidy museum that attracted visitors... The paragraph marked with red asterisk maybe provides an interesting clue. The last two images at the bottom of this web-page are pictures of technical documents - which supposedly were all destroyed after the war on Churchill's orders. So how were these pictures obtained, and is this where Tony Sale got a lot of the details he needed to reconstruct Colossus? Tony Sale passed in 2011 - by which time a little more (but not much) was known about the story of Colossus. But by now his "rebuild" was well-enough established as the prime exhibit of the museum to assure it's survival. Over time, more publications appeared with information about the overall activites of Bletchley Park during WWII, and the more the museum grew and prospered. Tony Sale's replica eventualy assumed flagship status in the Museum's publicity - ironic recognition for an effort that once got Tony banned from the premises. The museum went on to grow from the efforts of a bunch of amateurs squatting in premises loaned to them for the purpose by the Post Office - the nominal "owner" of the Bletchley Park estate since the end of the war. But with all the publicity and public interest growing in the Museum's activities, it was transformed into an official State-run entity, to become known as The National Museum of Computing (TNMOC - as it is now referred to more briefly) and is claimed to be home to the world's largest collection of working historic computers. An inside joke that will only be understood by early computer programmers (who coded their programs onto punched cards in order to feed them into the computer). The above acronym TNMOC has an eerily familiar ring to it - highly reminiscent of the string "TNEMMOC" which will be familiar to a lot of such programmers. If you happened to put a punched-card into the card-reader the wrong way round, you would be reading it backwards...

Then suddenly,in the first weeks of 2024 - some 80 years after the nominal birth of Colossus, the British Government released some more pictures and circuit diagrams - which supposedly had all been destroyed under Churchill's orders.

These last pictures appeared after 80 years. And after strict instructions from the highest of Government Authorities that any such artefacts be destroyed. Are there more revelations to come that yet linger in a safe in Whitehall (or Cheltenham) somewhere? Or perhaps even somewhere on the other side of the Atlantic - perhaps at The University of Waterloo in Toronto or at MIT (i.e. Mitre Corp.) in Boston (Eventually called home by Bill Tutte and Gordon Welchman respectively) (Unsupported and wild surmise on my part - but interesting food for thought anyway). We can but hope - but it may take another 20 years and possibly coincide with a Centenary celebration.