I found the perfect example, using all 3 main levers and that’s how almost all programs work.
Binary to decimal converter
One enters the 3 binary digits on the input sheet X and the computer outputs the decimal value on top.
Input (not to scale):
0 1 0 1 0 1
Output sheet - - 1 7 0 6 - 3 5 2 4
When building, you should start with the output sheet, making the squares and write the output numbers or text. Then make the mask with the 3 holes matching these squares masking out every other square. This is the lever 2 (on right). Then make the one with one hole (lever 1, left), then the other with no holes.
Put lever 1 on the output sheet and by sliding to the right you have the positions for the left 0 and 1. Same for the other 2 masks.
The exact positions of the masks are not exactly shown, and it’s hard to imagine without building the paper computer. I threw away my computer, so I can’t check that. But as you know the answer of the decimal value, you should be able to manage, what hole should show what number.
By moving the lever 3 one more column to the right you would have a 3rd position like A B C. That would not make sense for entering a binary digit here. I have to search for another sample using lever 4 and or/ the memory doubler. One could add more levers and alter the output sheet.
I was captivated by the design when I saw the cover and it has been stuck in my mind since. And with how it functions, it feels like there really was a lot of thought that went into it!
I see, so X part is also interchangeable!
Thank you for the software example! I was interested in trying out the binary to decimal converter but couldnt figure it out on my own.
I will ammend the errors you mentioned and test it out!
As for the Fensterblende being higher up, when you say it covers a part of the display would that look like:
oo xx
where the oo are covered and the xx are still visible?
I would love to making some custom software for it once I wrap my head around using it, and to also physically build the computer. My first attempt at building it was a bit of a mess.
Thank you again for your help and for sharing this!
No, as said Z4 has no holes at all.
The RAM doubler “Frontvorsatz” (to put over the output window) has a narrow vertical hole. Sheet is 60x300mm. Hole 23x43 in the center, so I think just showing one column. You now have 24 (2x12) instead of 12 output bits. So more columns.
You won’t need both anyway. Even the program from the book cover not using any of them. I haven’t found any program using Z4. There are 2 examples with the RAM doubler.
You should first try with the 12 bits.
As they also changed sheet X in the book, the book cover obviously showing a prototype. At the end it says 12 bits but some earlier examples are 14 bits.
Yes, I also had trouble with building. Especially when not having cardboard but paper.
You spend more time with building than with the software.
I wonder how many books were sold, how many really made that computer and how long they have fun with it.
Oh, I’ve seen that I posted that example before. But it’s probably the best and easiest one to start with.
I left the hole right in the center for now as I am unsure if it should be to either side.
Does the software sheet look different for programs with the RAM doubler?
Does the “Frontvorsatz” move, or does it remain stationary as I currently picture it?
Luckily I do have some cardboard, but I also tried with paper at first in case I messed up and wasted the cardboard.
It is interesting to wonder how many were actually built. I feel like they would probably have been built by adults or teenagers at the youngest.
Even without being a true computer, in the modern sense, the visual design and the novelty at the time when computers still unobtainable for ordinary people should have created some interest!
I feel like for many more time was probably spent building it than playing with it unless, like you suggested they began modifying the machine or started trying to make their own software as well.
The Frontvorsatz is put over the complete front (display), hence the name.
It has lids on left and right to fold over the edges. At the bottom of the right half is a cutout some mm high to allow the lever (Z4) to move through it (0–1). The Frontvorsatz does not move.
The output sheets has just twice as much columns. You have to check the distances between the output numbers so that just one column is shown. There are no photos of neither sheets, just regular text printouts.
The input sheet x varies like with the regular output.
Here a software of a detective game, sheet X:
outside? at daytime? yes no yes no purse handbag goods clothes automat car
The output using the Frontvorsatz just has numbers on where the criminal has that file number at a police card catalog. There are just some suggestions that the car thief at day has file 22. One has to make up the story himself.
But again, you should start with the regular 6 or 7 columns. It’s difficult enough to build it. Maybe use a thin paper and back light to match the holes or even a transparent foil. Or patch and glue some stripes together. When it all works you could later experiment with the Frontvorsatz.
If you still have trouble you can try this on your PC where you can zoom the masks and change the holes.
I can later give some more software examples. Most are similar and just using 3x 2 bits yes/no inputs.
I will make the corrections to the Frontvorsatz as mentioned
Thank you for adding another software example as well!
As you suggest, I will try it on my computer first to make sure I have all of the holes in the correct places. Then I’ll try building it with paper and testing it out with the 6/7 column software when I have time over the weekend!
I will upload some pictures of my attempt at using it over the weekend as well!
As I was trying to assemble it, I realized I messed up the measurements somewhere along the line, haha. Since since the important parts aren’t fitting together right now I will have to make another attempt.
I think I messed up the measurements when I adjusted the two mask levers.
While redrawing it to print out, I realized I may have misunderstood how to put the two mask levers together previously and this is my current attempt. (measurements still not fixed)
Looking at it now I can see where my measurements got messed up, but I must have overlooked it after getting distracted. I hope to give a better update soon, maybe I should try using it as overlayed images for the time being before printing it?
Despite having had fun coloring it, I only have a black and white printer haha.
