Kyle Rankin @kyle@librem.one

This is a Marchant "Silent Speed" ACR8D electromechanical calculator from the 1940s. It is currently jammed up, stuck on a division problem it never finished, and is apparently the most complicated mechanical calculator out there. Wish me luck!

To close out this thread, here is correspondence between Felt himself (the inventor of the Comptometer) and Zenith Pub. Co.

Even though I have more "advanced" mechanical calculators like my Monroes, the more I use this Comptometer the more impressed I am at the design. It's actually faster to use than my Monroes, at least for addition and multiplication.

Experts would only use the bottom rows so their hand was stationary. To enter larger numbers they'd enter two smaller numbers so to enter an 8 they'd enter 4 two times. This and later models had features to catch "fat finger" errors and partially-depressed rows.

Division was possible via repeated subtraction starting from the left and shifting to the right. There were no underflow bells, you'd just have to know when to stop subtracting a row. This is hard to do one-handed so I didn't film a video of that.

Subtraction was weird. You'd subtract w/ addition by the complements method, but would first subtract one from the number, then press down that number using the small digits on each key. You also slide the correct metal tab at the bottom to stop the carry. Here's 9 - 2.

You can perform many calculations surprisingly quickly and w/ one-hand. A well-trained Comptometer user was probably as fast as you'd get until electromechanical calculators. Here I'm calculating 1024 x 768, which just requires pressing 768 a few times and shifting left.

The Comptometer had a superior design. Pressing a key immediately updated the register, no need to pull a lever (the lever here clears the register). This design was so effective it stayed essentially the same (with minor improvements on error prevention) through the `50s.

This is a Comptometer Model E mechanical calculator, made between 1913 and 1914. Comptometers were made starting around 1900 and were a direct competitor to the 1908 Burroughs adding machine I featured earlier.

@dredmorbius Summary is:

1. MS (and AD) strongly contributed to and enabled a culture of bad passwords. While they didn't invent bad password policy, their defaults and recs became gospel to many IT admin and AD enabled bad policy to scale, training a generation of computer users to make bad passwords.

2. "Passwordless future" enables vendor control of hardware, as auth is strongly tied to hardware security, which is anchored in trusted (signed by MS) software.

I didn't realize just how much I blamed Microsoft for the current state of passwords until I sat down to write about their "passwordless future": https://puri.sm/posts/microsoft-ruined-passwords-now-aims-for-a-passwordless-future/

More than 26,000 PG&E customers were without power in the Bay Area today because of fog and mist. Fog. and mist. https://www.nbcbayarea.com/news/local/over-28000-customers-experiencing-power-outages-due-to-fog-mist-pge/2660562/

This is the carry mechanism for the Monroe. The bars form a wave and the last few move, but were completely seized up. A few hours with some oil, pliers, a screwdriver, and ultimately a heat gun, and it finally loosened up. Subtraction finally underflows all the way to the left!

Yesterday I spent a few hours restoring this Monroe Model G calculator. It was only after putting everything back together that I discovered the accumulator is only underflowing half the digits when doing subtraction/division, so I get to take it apart again today and fix that.

@twrightsman I'm using native apps in this case.

@KekunPlazas @tbernard This is one big reason why I've been experimenting so much on the side with running browsers inside bwrap so I could have a persistent but externally-sandboxed browser for more trusted browsing, and a disposable sandboxed browser that erased its sandbox when the window closed, for untrusted browsing (like opening URLs from external sources).

The implementation is pretty simple, it's just a matter of maintaining bwrap rules long-term.

To elaborate, this is a disposable VM just for opening random, possibly untrusted links other people send me. I do most of my own browsing in a different VM with ad and javascript blocking in place. It's always jarring to see just how bad the web is without all of that in place.

How do regular folks stand browsing the modern web? I have a VM for opening random links with no javascript or ad blocking. When I open certain news sites my laptop fans spin 100% loading all the ads, and it's almost impossible to read the actual story.

@RyuKurisu I believe modern CPUs have a lot of different sets of instructions, but my understanding, if we go back to early binary computers, is that they implemented Boolean logic (AND/OR/NOT and their combinations), from which you can derive things like addition operations.