Active mechanical logic gates

[Thomas Puettmann]

Hello,

not yet a calculator, but hopefully on the way towards it:

https://youtu.be/Lt0alWQzkWY

The project aims to mimic electronic digital logic purely mechanically (except for a motor, which could be substituted by a windmill or a steam engine).

My idea is that the educational value is that you can see, hear, and feel everything that is going on (in particular, the amplification) unlike in electronics where ICs are black boxes.

More complicated flipflops and a minimized full adder are on the way.

One of my goals is a small 4-bit RPN calculator (most probably just with + and -).

The project is of course completely open and purely educational.

[Paul Dale]

Lovely!

Pauli

[jdebord]

Also see:

https://www.meccano.us

Meccano differential analyser.

[KeithB]

Too bad Ms. Lovelace is not around to program it.
https://en.wikipedia.org/wiki/Difference_engine

Babbage is the source of two of my sigs:
"Errors using inadequate data are much less than those using no data at all."

"On two occasions I have been asked [by members of Parliament], 'Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?' I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question."

Also, for a version of what might have happened if the Difference Engine had worked:
https://en.wikipedia.org/wiki/The_Difference_Engine

[Paul Dale]

Another series are Konrad Zuse's, starting with the entirely mechanical Z1.

What I found interesting about this one is position is not used to flag binary bits, rather motion or it absence is.

[Ren]

Funny you should ask...
Mechanical Logic Gates just showed up on the Hackaday blog!

https://hackaday.com/2024/09/20/mechanic...ification/

[Thomas Puettmann]

(09-20-2024 03:26 AM)Paul Dale Wrote:  Lovely!

Thanks Pauli! Some 10 years ago you recommended using weights over strings to me. I think one can see that I am still very happy with that advice.

[Thomas Puettmann]

(09-20-2024 06:09 AM)jdebord Wrote:  Also see: https://www.meccano.us
Meccano differential analyser.

Yes, indeed the differential analyser with its torque amplifiers was another source of inspiration. Just by analogy: One uses the transistor as an amplifer for analog and digital signals. Why not use the torque amplifier or capstan in digital systems?

[Thomas Puettmann]

(09-20-2024 06:50 PM)KeithB Wrote:  Too bad Ms. Lovelace is not around to program it.
https://en.wikipedia.org/wiki/Difference_engine

The difference engine is something I could not implement in a way that pleases me, at least not up to now. I could cover the LEGO version by Andrew Carol but I would like to find some other mechanism.

But Ms Lovelace would definitely be welcome!

[Karl-Ludwig Butte]

(09-20-2024 09:41 PM)Paul Dale Wrote:  Another series are Konrad Zuse's, starting with the entirely mechanical Z1.

What I found interesting about this one is position is not used to flag binary bits, rather motion or it absence is.

There is a wonderful video about how Konrad Zuse's mechanical logic gates worked here. You can skip the introduction and start at 4' 22'' of the video. The shape of the metal sheets (shown in red, blue and yellow in the video) corresponds to the shapes actually used by Zuse. He and his colleagues, who helped him build the Z1, sawed out the metal sheets by hand. The original Z1 with all its documentation was completely destroyed in WWII. Konrad Zuse built a replica of the Z1 at the end of 1986 based solely on his memory. This replica can be seen at the Deutsches Technik Museum Berlin and in this video.

Best regards
Karl

[EdS2]

Thanks for the video link!

[rprosperi]

Excellent videos!! Thanks for posting these Karl. This is another good reason to visit Berlin, which I hope to do in the next couple years.

[badacktor]

reminds me of the lego pneumaddic projects by kevin clague:
https://www.kevinclague.com/l/pneumaddic/
https://www.kevinclague.com/l/pneumaddic-ii/
https://www.kevinclague.com/l/computing/
https://www.kevinclague.com/l/little-secrets/
https://www.kevinclague.com/l/or-gate/

he wrote about it in length in "Lego Mindsorms Masterpieces" in 2003, available on archive.org to borrow (they're back, baby!):
https://archive.org/details/legomindstor...e/mode/2up

somewhere I've got the pdf of that book saved. somewhere else I think I have the physical book, probably purchased at borders books back in 2003-2004.

edit: oh heck, reminds me of a project from wesley kagan, too:
https://www.youtube.com/watch?v=udCpBsylfIw

[Thomas Puettmann]

I have now managed to build a full adder in a somewhat reduced form by building a combined NAND/XOR gate:

https://youtu.be/BPKASRMyvdw

On the way to build an RPN machine ;-)

Well, actually, I want to build a 4-bit calculator with +/- ALU and accumulator, 4 levers to input data, one lever to choose +/- and one ENTER lever.