Kyle Rankin @kyle@librem.one

To clear the register, you turn the knob on the bottom right side anti-clockwise until all the digits say 0.

The chain only moves in one direction, so to subtract you have to use the complements method. To subtract 42 from 31342, I add 9999958.

These are portable, but are bigger and heavier than other pocket calculators of the time and primarily sat in or on a desk using the kickstand, and were used for quick arithmetic. To add a number, insert a stylus at the corresponding digit and drag down to the bottom.

These are known as chain adders. By inserting a stylus and dragging the chain down, you increment the register. You can see the carry mechanism in this video, which uses a spring-loaded tooth that rides along the outside of the gear and engages with the next gear only after 9.

These are Golden Gem portable adding machines made by the Automatic Adding Machine Company. The chrome one on the left was made around 1910 and the black one on the right, which has its original box, case, warranty card and receipt, was purchased in February 1941 for $9.16.

"If it's free, you are the product" stopped being true once the rest of the companies saw how much money there was in selling customer data. Now you are the product regardless of whether you pay.

It's so profitable to sell customer data that Vizio now makes 2x as much from that than selling TVs. Until the govt outlaws this data collection, your only recourse to protect your ⁨#privacy⁩ is to buy things from the few companies left that respect it. https://gizmodo.com/welp-vizio-now-makes-twice-as-much-from-advertising-as-1848034943

@sohkamyung I admit that it's finding out about the Jacquard loom as I was researching the history of mechanical calculators that is partially responsible for my wanting to take up weaving.

@GirthyChode@fosstodon.org I can do some basic hand-sewing, just enough for simple repairs really, but don't know my way around a sewing machine. I do know how to crochet though and have made large blankets that way, although it's been many years.

New hobby: I'm taking up weaving! The pun possibilities are looming in my warped mind.

@yaelwrites Oh no! Do you write/type notes as a backup normally?

Apple's talking about sideloading this week to shift the discussion away from App Store competition. If it had to compete with other secure iPhone app stores (like ones dedicated to gaming) it would have to lower its fees and improve its policies. It's about control not security.

@th Any recommendations for someone thinking about getting started with weaving? Please loominate me.

@th I could really see myself getting into weaving...

@HalvarFlake Welcome back!

@yaelwrites Wish I knew more than just the basics. While I've geeked out on plenty of other parts of history (and currently in the middle of Durant Vol III in the hopes that by the time I read all volumes I'll at least have a reasonable foundation), I haven't given this period the same deep dive yet.

Division aside though, this is my favorite lever style adding machine in my collection to use, due to the subtraction key and overall key placement that enables one-handed operation. I could actually see myself using this to balance a checkbook if I still did that sort of thing.

Division is repeated subtraction while counting your lever pulls and watching the register for underflows, which is a pain to do, and to demo on this type of adding machine.

Multiplication is repeated addition, shifting left for each digit in the multiplier, like other lever adding machines. By pressing down the repeat key the keys stay depressed after you pull the lever so you press the Correction key to release them and shift left. Here is 12 x 12.