here's a fascinating vintage Swiss washing machine that uses punch cards to program the wash cycle!
"For my laundry, I prefer Schulthess." she's holding the punch cards that she used to select a particular type of wash cycle. i wonder if anyone ever tried to custom make one of these cards... 🤔
turns out the company is still around, and still making washing machines! schulthess.ch i suppose you need one of these if you want your clothes to be Swiss Clean™
aren't these just lovely? 😍
another vintage Schulthess ad.
😍
the top row of sprocket holes are used to draw the card into the reader and pull it along using a low-speed motor/timer. the holes and slots control switch contacts that activate the various functions of the washer--the valves, motor, and perhaps solenoids.
it is more common for a washer to have a control unit like this, with fixed cams that open and close switch contacts. incredibly, in 2021, many washers *still* use this type of mechanism.
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i printed a new panel insert that has two BNC sockets on it (the original probes would have had captive cables)
the tricky part is that this oscilloscope has a 333K ohm input impedance instead of 1M like umm every other scope on the planet. fortunately someone designed a little conversion circuit...
in honor of Sim Wong Hoo, here's a quick historical review of the Sound Blaster! 🧵
but first we have to go back to their first sound card, the Creative Music System from 1987. (image credit: Bratgoul on Wikipedia)
this card has some special "CMS-301" chips. if you peel back the sticker, they have had their top marks removed. they're actually SAA1099 synthesizer chips made by Philips. Creative wrote music composition software for musicians on the PC.