VirtualColossus
virtualcolossus.bsky.social
VirtualColossus
@virtualcolossus.bsky.social
Colossus was a computer built during WW2 to crack the German Lorenz. Website simulation of it you can use in full 3D, plus 3D Enigma, 3D Lorenz , Typex, Turing-Welchman Bombe & Hagelin M-209

https://virtualcolossus.co.uk
This week, I've started working on the paper tape reels which are held in the base of the SG-41. Two tapes can be fitted; one for the cipher text and one for the plain text to be printed. @tnmoc.bsky.social @threejs.org
November 15, 2025 at 9:42 AM
Postbox in Newton Longville. We will remember them. #Rememberance #LestWeForget
November 9, 2025 at 10:37 AM
We are getting so close now! This week sees the completion of the final part of the actual SG-41 mechanism; the ink cartridge & upper paper feed rollers. So is that it ... all done? Not quite, there's one important part missing. @tnmoc.bsky.social @cryptomuseum.bsky.social @threejs.org
November 9, 2025 at 9:21 AM
New Rememberance Day postbox topper has been installed outside Bletchley Park / @tnmoc.bsky.social if you're visiting either. You can even press the drum to hear the noise!! I love this, remembering all the WRNS who served running the Bombe machines. Superb work Clare Reeves & Amanda Vines
November 1, 2025 at 4:20 PM
The end is in sight for Virtual SG41! I've started into the paper feed block which I've been saving until last. This is the final big section to do and includes the mounting for the upper rollers, the ink cartridge, release button, paper tape reels and of course the paper itself.
November 1, 2025 at 10:34 AM
JePu Machines have released a video in English & German on cracking an Enigma message using my Virtual Bombe and Enigma! It goes into huge amount of detail from encrypted message to solution. Nice work!

Enigma Codebreaking with the Turing-Welchman Bombe!

youtu.be/eHzsAoKXmZM?...
Enigma Codebreaking with the Turing-Welchman Bombe - do it yourself!
YouTube video by Jens Puhle
youtu.be
October 30, 2025 at 1:00 PM
Virtual Schlüsselgerät 41 (SG-41). Another week and yet another mess of levers in the CT scans that do something .. but what? One of those cases where I'm just going to have to model & animate them in @blender.org & @threejs.org to find out. @tnmoc.bsky.social @cryptomuseum.bsky.social
October 25, 2025 at 9:16 AM
@microsiervos.bsky.social have posted a brief review of my Virtual Enigma. So glad they found it interesting. They did say "using the mouse and pressing buttons and switches isn't very intuitive". Any thoughts on how to make it easier or clearer what you need to do?
October 22, 2025 at 2:07 PM
It's time to fill out some of the metalwork that holds everything together. It's no wonder the SG-41 weighed in at around 13kg especially as Germany were running out of lighter metals by the end of the war.
@cryptomuseum.bsky.social @threejs.org @tnmoc.bsky.social
September 27, 2025 at 9:10 AM
One of the final external controls completed, the F/L knob. This switches the SG-41 between Funktion (Operate) and Löschen (Clear). Clear mode releases the mechanism from the cipher wheels so they can be moved to a new position or reset. @tnmoc.bsky.social @threejs.org @cryptomuseum.bsky.social
September 13, 2025 at 8:23 AM
Last month, I was thrilled to be invited to GCHQ in Cheltenham to see their rare SG-41 cipher machine for real!
It has answered many questions about this amazing WW2 machine. I can now move on & complete my latest sim which will be released (hopefully later this yr) on my site virtualcolossus.co.uk
September 5, 2025 at 4:16 PM
That is SO cute! Look, it's a little knitted Colossus
I WANT ONE!
Colossus fans! Don't miss the UK premiere of The Longest Yarn 2: Britain at War at Southwell Minster (3-27 Sept).
This incredible "wool art" exhibition features the Colossus computer!
Find out more: ow.ly/twrO50WPw06
#Colossus #TNMOC #TheLongestYarn #SouthwellMinster
September 3, 2025 at 12:32 PM
Reposted by VirtualColossus
A new and very informative posting by the Sigint Historian, which sets Sigint history in perspective and generally offers reflections for historians.

siginthistorian.blogspot.com/2025/08/reco...
Records and Memory
One of the more interesting questions I had to answer as GCHQ historian was why a large collection of intercepted message logs encrypted i...
siginthistorian.blogspot.com
August 31, 2025 at 10:58 AM
I've been continuing work on the paper feed mechanism after a very exciting visit which has helped a huge amount (more on that soon). The paper feed lever allows you to extract your printed cipher/plain text from the SG-41. @tnmoc.bsky.social @cryptomuseum.bsky.social
August 31, 2025 at 8:52 AM
Reposted by VirtualColossus
Yesterday we unveiled a new mural honouring Tommy Flowers, He was the brilliant engineer behind the Colossus computer. A truly fitting tribute to his genius and legacy.Thanks
@HeritageFundUK
& @TommyFlowersFdn
#TommyFlowers #Colossus #VJDay #DigitalLegacy Photo credit: Andy Taylor & Dave Wild
August 16, 2025 at 6:37 AM
Jim Sanborn is to auction off the solution to K4 of the Kryptos Key, the outdoor sculpture that sits at CIA headquarters.
Would you keep this to yourself and guard the secret to allow the game to continue or release for the world to know the answer?
www.wired.com/story/jim-sa...
The Kryptos Key Is Going Up for Sale
Jim Sanborn is auctioning off the elusive solution to K4, the outdoor sculpture that sits at CIA headquarters.
www.wired.com
August 15, 2025 at 10:31 AM
Reposted by VirtualColossus
Celebrate the legacy of Tommy Flowers! Join us at The National Museum of Computing on Friday, 15th August to unveil the new Flowers Mural.
Secure your place here: bit.ly/4ljjOuJ
@fitzroviaNoir @tommy_flowers_aberfeldy #TommyFlowers #Colossus #TNMOC #ComputingHistory
Preserving the legacy of Tommy Flowers: uncovering lost histories
Join us to honor the GPO engineers who worked on Colossus, as we showcase the Tommy Flower Mural
bit.ly
August 9, 2025 at 3:29 PM
As well as working on modelling & animating the complex paper feed mechanism, I've been having a play adding a few extra visuals. Some useful (hiding specific parts of the mechanism to see how it works) and some just eye candy!

@tnmoc.bsky.social @threejs.org @cryptomuseum.bsky.social
August 9, 2025 at 8:41 AM
Just when I thought I'd got past the most complex bits for Virtual SG-41, I find the paper feed mechanism. It's buried in deep on the left-hand side and includes a cam, 3 levers & 2 ratchet/pawls all which need to be modelled & animated! @tnmoc.bsky.social @cryptomuseum.bsky.social
July 29, 2025 at 8:02 AM
I've added the letter counter to the SG-41 this week so take a look at how that works. Also, I've animated the folding handle so the machine can be packed away for travelling.
@tnmoc.bsky.social
July 19, 2025 at 7:53 AM
Reposted by VirtualColossus
What an incredible visit to The National Museum of Computing (@tnmoc.bsky.social) yesterday!

Seriously, it's one of the most brilliant museums I've ever had the pleasure of exploring

It’s not just about seeing how tech progressed; the passionate staff weave incredible stories around the exhibits
🤩
July 13, 2025 at 10:56 PM
I broke more than fixed this week! I'd placed a few items in the machine out of line so last few bits didn't fit. I re-checked the scan so all fixed now!
The question to answer today - "What happens if you run out of paper?"
@bletchleypark.bsky.social
@tnmoc.bsky.social
@cryptomuseum.bsky.social
July 13, 2025 at 4:35 PM
MK Dons pay tribute to Bletchley Park Codebreakers with new away shirt! It features Enigma key tops on the fabric as a tribute to the Bletchley Park codebreakers. www.miltonkeynes.co.uk/sport/footba...
Dons pay tribute to Bletchley Park Codebreakers with new away shirt
The new shirt pays homage to the Enigma Codebreakers of Bletchley
www.miltonkeynes.co.uk
July 7, 2025 at 5:30 PM
Lots to show you today for Virtual Schlüsselgerät 41. Working out the print mechanism meant going back to uncover the cage drive works in detail! New drive mechanism, the print wheels working and switching between encipher/decipher. Phew! @tnmoc.bsky.social
July 5, 2025 at 10:03 AM