mxkSince I will try to have a relaxed day, expect some sorted thoughts from the last week and in particular yesterday's museum visits.
I start with one of the most unusual exhibition pieces:
A Xerox Parc Beanbag Chair.
I got distracted yesterday, but to continue what I promised:
Everyone who knows me, knows that I am slightly obsessed with the Zuse #z23. So I was happy to see (small) parts of it at the #ComputerHistoryMuseum.
But the choice of cards is slightly confusing.
This computer is built out of discrete transistor logic, on relatively low density cards. So what happened here is, they apparently selected 2 visually interesting cards and by doing so picked cards which are analog in nature and not part of the compute logic at all!
One of the cards has 601 visible, which is the identifier of this card type, which can be looked up in the official documentation, which luckily is hosted online by multiple universities.
This tells us, that this is actually part of the storage drum (think hard disk, but the data is on the side rather than on the top surface) and it's a "single impulse amplifier".
I totally see how that happens, as a card with 4 transistors and 4 resistors isn't visually interesting to look at.
I am also very aware, that I am probably one of 10, certainly less than 100 people alive, who would notice this.
We talk about an obscure German computer from the late 1950s after all.
Jay16K@mxk There was Hackertours at the #WICMP10 touring the operational Z23 at #ISER 😉 Maybe this will return for #WICMP11
Check out: https://www.iser.fau.de/
Check out: https://www.iser.fau.de/
@Jay16K this is the Zuse z23 I know in and out and I could have given that tour as well.
Edwin and Volkmar are exactly 2 of the hand full of other people knowing this computer well enough to spot at a glimpse what cards are on display here.
If you need a proof: this blog has a picture of me holding the old scratched drum.
https://blog.hnf.de/die-zuse-z23-laeuft-wieder/#:~:text=Nach%20langer%20Restaurierung%20nahm%20am,an%20die%20Uni%20geliefert%20hatte.
@Jay16K I would have joined, if I wouldn't have expected to just return from my business trip (and in the end I just returned on Sunday anyways due to a strike.)
Maybe I will even do a follow up to my MRMCD talk on the z23 🤔
Maybe I will even do a follow up to my MRMCD talk on the z23 🤔
@mxk looking forward to it ❤️
Drehumdiebolzeningenieur@drehumdiebolzen @mxk ja, wir hatten Spaß am Wochenende in Erlangen, im Closing hieß es "... und bis zur WICMP11 oder auf einem beliebigen Chaosevent in deiner Nähe!" also wird es wohl eine weitere Chance geben 😉
streyt
Dave Fischer@mxk When showing examples of boards from that era, I always try to pick a flipflop or a nand gate.
@davefischer that's what I would choose as well.
For comparison this is a z23 flipflop:
https://museum.cs.rptu.de/Rechner/Zuse/Z23/Schaltbilder/Bausteine/Logik/Ts100-a.JPG
And this is a nand:
https://museum.cs.rptu.de/Rechner/Zuse/Z23/Schaltbilder/Bausteine/Logik/Ts230-a.JPG
This collection of both documentation and photos is luckily pretty complete, even though it is not the most accessible, since all is in German and the plans predate modern standards and rather make up their own symbols and conventions.