Sound #troubleshooting techniques can be applied to all classes of problems, and I'm using the same approach I wrote about in DevOps Troubleshooting. I identified an issue (shift mechanism) and to narrow down the cause I now need to study and understand how this mechanism works.
I decided to start by fixing the shift mechanism, which stutters when shifting left. I'm hoping resolving that may also resolve some of the other issues. I was able to locate a service manual for a similar calculator which has some decent diagrams. #antique #calculator
Today we attempt to repair and refurbish a Monromatic CSA-8 electro-mechanical calculator from the 1950s-1960s. At the moment addition and subtraction don't update the accumulator among othet issues, I hope just from seized gears. #antique #calculator
@Mayana You should! And the cost of a razor is more than made up by the incredibly low cost of the shaving soap and blades. A basic Tech would be a great way to learn proper technique, and you might be surprised at how affordable some of these other blades can be at antique and thrift stores.
@PublicLewdness Basically an old, used car.
Cars continue to copy the smartphone business model, now have mandatory pre-installed services and apps (and the tracking that comes with them): #privacy https://www.thedrive.com/news/gm-makes-1500-onstar-subscription-mandatory-on-gmc-buick-cadillac-models
You have to hand it to them... #privacy https://www.engadget.com/amazon-one-palm-payment-whole-foods-california-195712253.html
The biggest challenge with filing expense reports is deciding which #antique adding machine in my collection to use to add up receipts. Today's winner is an RC Allen model 75. #vintagecomputers
@mrdoornbos I have that R C Allen model! Very nice hand crank adding machine with subtraction feature. It is what I would reach for to balance a checkbook if I needed a paper trail.
@jonny See my previous thread to see a normal division.
@yaelwrites Eh I've found different people find different words offensive so the best course is to attempt to be respectful of what bothers others once they let you know.
Here's a bonus video of what happens when you divide by zero on an electro-mechanical calculator. #infiniteloop
My Marchant Silent Speed is all cleaned up and ready to go with the rest of my collection! #antique #calculator
Here's another view of the same operation from the back so you can see more of the gears move.
It's worth mentioning that this is doing long division via repeated subtraction completely mechanically, just using the electric motor to power the gears. If you watch closely you can see it detect underflows, increment, and then shift right to the next digit.
Success! A little cleaning and lubrication freed up the stuck registers enough to do long division. Here's the Marchant Silent Speed approximating Pi. #antique #calculator
The Marchant Silent Speed #antique #calculator restoration begins! Here's hoping this is as far as I have to take it apart today.
Tune in to our new episode! @katherined and @dsearls talk to @kyle of @purism about the data cars collect, where it goes, and how we’re really just driving around in a smart phone that we don’t even own.
Visit the following link for full episode - https://www.reality2cast.com/121
@EdS I relied on John Wolff's documentation when I was attempting to repair a previous Silent Speed. Incredibly complex machines. The official service manual just had drawings and it was handy to see high-quality pictures of the mechanisms.
From John Wolff's museum:
"The Marchant "Silent Speed" and its descendants use a complex and unusual continuous-drive mechanism based on proportional and differential gearing. Every column incorporates a ten-speed gearbox with three drive shafts and five selectors. The accumulator tens-carry mechanism is contained within the carriage, using a differential gearing mechanism with two planetary gearsets per digit."
http://www.johnwolff.id.au/calculators/Marchant/Marchant.htm
See also Jaap's pages:
https://www.jaapsch.net/mechcalc/marchant.htm
Technical author, FOSS advocate, public speaker, Linux security & infrastructure geek, author of The Best of Hack and /: Linux Admin Crash Course, Linux Hardening in Hostile Networks and many other books, ex-Linux Journal columnist.