Kim Kirk 👩🏽‍💻🍱🍡Jan 4, 2023
Victor Gijsbers
Looking for people who know something about early computing, especially in the Netherlands. Please boost and help me solve the mystery of this custom made plate that used to belong to my grandfather Bram Jan Loopstra, one of the pioneers of Dutch computing. What do the pictures mean? #computing #history (EDIT: Wow, thanks for the overwhelming response! You may have to check the post on my instance to see all the MANY helpful reactions.)
Jan 3, 2023 at 3:07pmWeb
Show threadVictor GijsbersJan 3, 2023
The binary is obviously a date, 8-3-1956. That's the year that my grandfather and his collaborators finished the ARMAC computer. So my first hypothesis is that it's a commemorative plate for that. If so, the pictures may have something to do with this computer.
Show threadVictor GijsbersJan 3, 2023
The words at the bottom are the motto of early modern Dutch scientist Simon Stevin. It means something like: "It's a miracle, but not a miracle", indicating the power of science to explain the seemingly miraculous.
Show threadpenguin42Jan 3, 2023
@victorgijsbers The diagram on the left to me looks like a valve; possibly a pentode: https://commons.wikimedia.org/wiki/File:Pentode_symbol_labeled.svg
The thing at the top I'm guessing is a core memory?
The thing to the right looks to me like a diagram of hysteresis ( https://en.wikipedia.org/wiki/Hysteresis ) - which hmm I'd guess would be related to the magnetic cores??? But hmm the lines with the black blobs; it could be a baudot representation https://en.wikipedia.org/wiki/Baudot_code
File:Pentode symbol labeled.svg - Wikimedia Commons

Show threadBarry Schwartz 🫖Jan 3, 2023
@penguin42 @victorgijsbers Oh, yes, that’s certainly a pentode. (The surrounding circle would just mean it was in a tube by itself.) And that’s definitely hysteresis, which is symbolic of (any kind of) memory.
Show threadBarry Schwartz 🫖Jan 3, 2023
@penguin42 @victorgijsbers (I’m a little curious why a pentode instead of a triode, but I have very little knowledge of tubes/valves and certainly not of their use in digital circuitry.)
Show threadpenguin42Jan 3, 2023
@chemoelectric @victorgijsbers Yeh same here; I wonder if you end up with something like a 3 input AND gate?
Show threadBarry Schwartz 🫖Jan 3, 2023

@penguin42 @victorgijsbers Could be. Let’s see ...
‘Tube computers primarily used triodes and pentodes as switching and amplifying elements. At least one specially designed gating tube had two control grids with similar characteristics, which allowed it to directly implement a two-input AND gate.’
https://en.wikipedia.org/wiki/Vacuum-tube_computer

So, good catch!

Vacuum-tube computer - Wikipedia

Show threadBarry Schwartz 🫖Jan 3, 2023
@penguin42 @victorgijsbers One might think it would have a special symbol, though, since it’s not a pentode in the usual sense.
Show threadMysteriousBenjiJan 3, 2023
@chemoelectric Wikipedia says that the pentode (as featured on the plate) was used heavily in some of the very early British computers; perhaps the Dutch did likewise?
Show threadTrans RescueJan 3, 2023
@chemoelectric @penguin42 @victorgijsbers
Pentodes have much more gain, so I'd expect a tube computer to use pentodes.
Show threadBarry Schwartz 🫖Jan 3, 2023
@trans_rescue @penguin42 @victorgijsbers
That makes sense.
Show threadSteven ReedJan 3, 2023
@chemoelectric @penguin42 @victorgijsbers the thing on the right looks more like the flowchart symbol for paper tape to me, but then I'm not sure why it would have a cross-hairs ..
Show threadBarry Schwartz 🫖Jan 3, 2023

@srtcd424 @penguin42 @victorgijsbers

The puppy tore up my paper tape of a BASIC program, so let’s not think about that. :D

Show threadStephen Rigden 🇬🇧 -> 🇺🇸Jan 3, 2023
@chemoelectric @penguin42 @victorgijsbers Can you expand on what you mean by ‘any kind of memory'? Is it, in your view, a purely physical phenomenon or could it ever be used in any wider senses such as a symbol of an event in engineering history?
Show threadWhat's it to you?Jan 3, 2023

@penguin42 @victorgijsbers

If he used the original ITA1 encoding, it says "G22 44.4"

Show threadGordon GuthrieJan 3, 2023
@penguin42 @victorgijsbers yeah that core memory deffo
Show threadAmin Negm-Awad🇪🇺🌍Jan 4, 2023

@penguin42 @victorgijsbers I think that it is a Baudot/Murray representation, too. But why it is alternating in to diagrams.

Another interpratation is that it is the configuration of a crossbar switch. But again: Why is it alternating?

BTW: 5 lines can be musical notation (staff). Unlikely …

Show threadwrenJan 3, 2023

@victorgijsbers

graph on the right looks like a magnetization hysteresis curve, which make me think that the dotted grids in the center represent core memory arrays. the drawing on the left is the schematic symbol for an indirectly-heated pentode

Show threadWolfgang TremmelJan 3, 2023
@victorgijsbers the pictures in the middle look like a 5 bit punch tape
Show threadAnne FisherJan 3, 2023

@wtremmel @victorgijsbers

The code for the middle section reads:

(Top dots)
0-1-0-1-0
0-0-0-1-0
0-1-0-0-0
0-1-0-0-0
0-0-0-0-0

(Bottom dots)
1-0-1-0-0
1-0-1-0-0
0-0-1-0-1
0-0-0-0-1
1-0-1-0-0

At that point in history, this is NOT likely to be ASCII. Can anyone decipher that binary?

https://itenterpriser.com/knowledge-base/what-is-punched-paper-tape-how-to-read-it/

What is Punched Paper Tape, and How to Read It ITEnterpriser

Punched paper tape was a way to encode data on rolls of paper, first used in the 1950s. So why are we still talking about it today?

ITEnterpriser
Show threadAnne FisherJan 3, 2023
@wtremmel @victorgijsbers
Show threadWolfgang TremmelJan 3, 2023
@AnneTheWriter @victorgijsbers read it from top to bottom or from left to right? As for code, lookup Baudot.
Show threadAnne FisherJan 3, 2023
@wtremmel @victorgijsbers
my deciphering was from top to bottom and left to right, yes. I'm not sure what the original intended.
Show threadWolfgang TremmelJan 4, 2023
@AnneTheWriter @victorgijsbers Perhaps its ARMAC related? According to this the ARMAC used 5-bit opcodes: https://web.archive.org/web/20131113021126/http://www-set.win.tue.nl/UnsungHeroes/machines/armac.html
ARMAC | Unsung Heroes in Dutch Computing History

Show threadAnne FisherJan 3, 2023

@wtremmel @victorgijsbers
I looked up Baudot. The possible interpretations are too many for my available time this afternoon, I'm afraid. Perhaps someone else can have more success?

https://en.m.wikipedia.org/wiki/Baudot_code

Baudot code - Wikipedia

Show threadAnne FisherJan 3, 2023

@wtremmel @victorgijsbers
Another Baudot chart. This one seems different? Using Baudot, the message makes no sense in any language-- too many constants. (Or maybe I'm doing it wrong.)

https://cs.stanford.edu/people/eroberts/courses/soco/projects/2008-09/colossus/baudot.html

Baudot Code

Show threadStephen Rigden 🇬🇧 -> 🇺🇸Jan 3, 2023
@victorgijsbers Or, perhaps, "Nobody can explain where that which is shown came from, but this dish can."
(see my later response in this thread for details)
Show threadSteve BellovinJan 3, 2023
@victorgijsbers My first thought is that the top center diagram shows core storage, the dominant form of RAM from the mid-1950s through the late-1970s, and the ARMAC used core (p 9 of https://apps.dtic.mil/sti/pdfs/AD0694623.pdf). The other two may represent other planes; each plane is one bit of many words. The diagram at the right is a hysteresis diagram, which is correct for core storage. (Core used a 2D arrangement of ferrite cores, though there was third diagonal wire woven through.)
Show threadDirk SteinsJan 3, 2023
@SteveBellovin @victorgijsbers I agree, the top one is definitely core memory (see https://ub.fnwi.uva.nl/computermuseum/CoreMemory.html for some pictures). The other ones below are bit sets, but to decipher it the order of the memory must be known.
Core Memory

Show threadSteve BellovinJan 3, 2023
@dirksteins @victorgijsbers I thought of that, but the wires from the core plane go down through it, which is why I speculated about it being another plane of core.
Show threadSteve BellovinJan 3, 2023
@dirksteins @victorgijsbers I should add: the dots at some intersections do work against my theory.
Show threadAI6YR BenJan 3, 2023
@victorgijsbers The figure on the left is a vacuum tube. In the 1950's they would have been used to develop computers (because transistors were not available at that point). http://www.quadibloc.com/comp/cp01.htm
What Computers are Made From

Show threadAI6YR BenJan 3, 2023
@victorgijsbers The middle column (grid) is clearly a reference to the way those computers were typically programmed; they had a grid of on/off positions to specify the operations to be taken by the computer (computer instructions). Probably an actual switch back in the 1950's, later these were done with punch cards.
Show threadAI6YR BenJan 3, 2023
@victorgijsbers The figure on the right is a reference to some kind of hysteresis curve/loop, which is typically an electrical or magnetic property.
Show threadAI6YR BenJan 3, 2023
@victorgijsbers This looks to explain some of the machine after the ARMAC, probably similar. here's that vacuum tube and grid used for logic, the left and center diagrams in your plate. (Correction: "Weerstand logica" is "resistance logic" in Dutch) https://docplayer.nl/10851283-De-bronnen-van-de-computer-en-de-rol-van-de-electrologica-x8.html
Show threadAnne FisherJan 3, 2023

@ai6yr @victorgijsbers
Assuming the middle section is punch ribbon, then this would be the code...

https://mstdn.party/@AnneTheWriter/109627253594416795

AnneFisher (@[email protected])

@[email protected] @[email protected] The code for the middle section reads: (Top dots) 0-1-0-1-0 0-0-0-1-0 0-1-0-0-0 0-1-0-0-0 0-0-0-0-0 (Bottom dots) 1-0-1-0-0 1-0-1-0-0 0-0-1-0-1 0-0-0-0-1 1-0-1-0-0 At that point in history, this is NOT likely to be ASCII. Can anyone decipher that binary? https://itenterpriser.com/knowledge-base/what-is-punched-paper-tape-how-to-read-it/

Mastodon Party
Show threadAI6YR BenJan 3, 2023
@AnneTheWriter @victorgijsbers Hmm, possible... could also just be instructions for that particular machine.
Show threadWorkshopshedJan 4, 2023
@ai6yr @AnneTheWriter @victorgijsbers I was wondering if it was simply the first programme they ran on the machine
Show threadLJNielsenDk 🕹️💾💿🎹Jan 5, 2023
@AnneTheWriter @ai6yr @victorgijsbers I was messing with a https://www.dcode.fr/baudot-code (which decodes from a number of different baudot codes at the same time including showing showing both the decoding if it's LSB first and MSB first)) the other day to try to try to decode it but I didn't get anything useful out of it, but maybe I missed something if it isn't just some instructions which would come out looking random if you don't know the instruction set of the machine.
Baudot Code (Telegraph) - Online Decoder, Translator

Tool to decode/encode with Baudot. Baudot code is one of the first telecommunication code in binary from a machine (telegraph), it uses 5 bits per character and 2 character sets.

Show threadJohn CarlsenJan 3, 2023

@ai6yr @victorgijsbers

Weerstand is Dutch for resistance, so "resistance logic" is likely an early name for resistor-transistor logic (RTL), which this would predate as a structural and functional equivalent.

Show threadAI6YR BenJan 3, 2023
@johnlogic @victorgijsbers Aha!
Show threadcthomborJan 3, 2023
@ai6yr @victorgijsbers well spotted! The "Weerstand logica" example in that slideshow looks like a 4-bit finite-state machine, perhaps counting up to 10? The "restore pulse" from the tetrode circuit at the upper left is fed to the screen grid of the first pentode; there's a drive pulse... and the function being computed is essentially hardwired into the resistive interconnections on the control grids of the five pentodes.
Show threadPammyStarr   ✍️Jan 3, 2023
@ai6yr @victorgijsbers
Keypunch cards.
Show threadEdwin GroothuisJan 3, 2023
@victorgijsbers it’s more “imagine, then it’s not a miracle” or “think about it, then it’s not a miracle”. Miracle as in an unexplained event.
Show threadmmu_manJan 3, 2023

@victorgijsbers the symbol on the left seems to be some vacuum tube, with filament, anode, cathode and several grilles.

On the right, it represents an hysteresis trace, like that of Schmitt Trigger logic gates.

At the top I believe it could be some core memory…

Show threadOliver KennedyJan 4, 2023
@victorgijsbers The rings along the top look like core memory ( https://en.wikipedia.org/wiki/Magnetic-core_memory ). The other grid patterns seem to be the same size as the cores... possibly a binary representation of some relevant system state?
Magnetic-core memory - Wikipedia

Show threadBrónaghJan 4, 2023
@victorgijsbers What I love about this is how closely it resembles the calculations used on a Jacquard loom.
My father was a linen weaver and his notebooks were full of these diagrams.
Show threadnobletroutJan 4, 2023
@victorgijsbers the twenty five circles in a grid formation look like twenty five circles in a grid formation to represent twenty five circles in a grid formation
Show threadGlummJan 9, 2023

@victorgijsbers

And I wonder wonder.

Show threadZahmbieNDJan 3, 2023

@victorgijsbers
I've been trying to find some information to decode the memory maps, but all I can seem to find is that the ARMAC had 34-bit words plus 2 parity bits, which doesn't seem to match up with the 25-bit groups on the plate.

I would normally try looking at the instruction set and text encodings for the computer and see if I could find any way to match it up, but it's tricky if the number of bits doesn't even match up.

Show threadTrans RescueJan 3, 2023
@victorgijsbers
The symbol on the left is a pentode vacuum tube. The symbol on the right is a hysteresis loop. The three in the center are probably core memories.
Show threadMalziJan 4, 2023
@victorgijsbers I guess it’s written in the op code of the arra 2 computer bc your grandfather startet work on the armac on the 1st of April 1956. so the dish is some kind of good bye present (sry for my English). As far as I‘ve red the instruction set of the arra 2 hat 25 operations this would fit into 5 bits which can hold 32 different values.
Show threadMalziJan 4, 2023
@victorgijsbers It could be the opcode of the armmac as well, since it had 5 bits too, but who gets a present befor working on a project. So, has anyone the opcode for an arra 2 or an armac on hand?
Show threadMre. Dartigen [maker mode]Jan 4, 2023

@victorgijsbers Do you know if there are any computing history museums, or any museums that have anything from the ARMAC computer? It looks like you've got tons of info on what the symbols and text are already, but places like that might maybe be able to tell you more about the background of the plate.

Usually they'll have things like staff photos, sometimes event photos too, and sometimes they'll have photos or even examples of commemorative merch, memorabilia, or other small items that were made for/given to team members or staff. If you can reach out to them they might be able to tell you a bit more, assuming it's definitely something official and not something your grandfather commissioned or made himself. (Even if it's the latter they might still be interested in photos.)

Show threadRaygan Kelly Jan 3, 2023
@victorgijsbers I'm not an expert but I can guess that the top image is an illustration or diagram of magnetic core memory https://en.wikipedia.org/wiki/Magnetic-core_memory
Magnetic-core memory - Wikipedia

Show threadVictor GijsbersJan 3, 2023
@raygan Interesting! My mother also found this, do you think it's a magnetic core memory (turned into a paperweight)?
Show threadRaygan Kelly Jan 3, 2023
@victorgijsbers I'd bet on it! Looks just like some images I've seen.
Show threadRaygan Kelly Jan 3, 2023
@victorgijsbers this is a really neat paperweight! If you look closely you can see the magnetic toroids, and it’s 16 x 16 which (I think) means this is 256 bits, or 32 bytes.
Show threadStephen ShanklandJan 3, 2023
@raygan @victorgijsbers Sure looks like core memory to me. Here's some IBM core memory from days of yore, on display at Computer History Museum. 1536 bits. https://flickr.com/photos/shankrad/52598590820/
IBM Model 64 magnetic core plane, 1536 bits

Flickr
Show threadWim🧮Jan 3, 2023

@stshank
The drawing on the right is the magnetic hysteresis loop, that is what allows the ferrite cores to "remember" information.

@raygan @victorgijsbers