Kyle Rankin @kyle@librem.one

To zero things out, you pull on a lever at the top. Basic tallying, like scrabble scores, can be done pretty quickly on one of these after some practice. You can also do multiplication via repeated addition and left shifts like with other adding machines.

To subtract, you slide a panel from the bottom upwards, which aligns new numbers with the holes. Now you slide up instead of down, unless you need to carry a one, in which case you slide down around the hook. I'm not a fan of this part of the design--it is pretty cumbersome.

As you slide rows down you notice some numbers in a row are colored red. That signals that when you add those numbers, instead of sliding down, you slide up and around the "shepherd's hook" to carry the one. Here I added 5.

This is a Tasco Pocket Arithometer. It was probably made in the 1940s but is based off of older Arithometer designs. It is sized to fit easily into a shirt or coat pocket. To add numbers you place a stylus in the appropriate row and drag down, which adds to the existing total.

@mc@mastodon.sdf.org You should check out local thrift or antique stores. Often you can find nice vintage razors for $10-15 that just need some cleaning. I have a knock-off of a Merkur Futur adjustable but I find I prefer my vintage razors.

@lwriemen Many 3D printers themselves use 3D-printed gears, so they at least can hold up to those stresses. In this case the teeth are small enough they might not hold up so well to constant stress against metal gears.

@mc@mastodon.sdf.org Yes, I rotate through my razor collection and shave with just about all of them. I just shaved with this red tip this evening as I had never shaved with one before. I already have a slim in my rotation so I know how it shaves.

Today's other antique find is this pair of mechanical pocket calculators. Both came with their original case but sadly neither had their stylus.

Each pocket calculator in my collection has a slightly different way of performing arithmetic, probably due to patents.

Today's antique finds: a Gillette red tip and a Slim adjustable. The red tip came with a wooden case which I don't think is original--my understanding is these originally came in a plastic case.

@aral I try to steer clear of these sorts of things so I don't know much about this particular controversy. That said, all of my (admittedly limited) interactions with Nick from Calyx over the past few years have been positive so at least based on my personal experience something seems off about this.

@ajmartinez That would be fun. At this point I'll need to source a replacement gear at a minimum and then completely remove the control unit to reset all the interlocks. I think the easiest path is to find another parts machine and then make one good machine out of both of them.

@GirthyChode I've been deep into the repair documents and engineering drawings for a week now tracing the inner workings. Fascinating machine. Unfortunately a replacement gear isn't an off the shelf item, so I'm going to have to keep an eye out for another one of these in a similar state so I can make one good one.

Well this is disappointing. While trying to loosen up stuck mechanisms a few teeth broke off of an important gear. Guess this is now a parts machine.

@eliasr @aral @claus In skimming the docs it looks like it lets the user set their own root certs, which is good. LinuxBoot is a reasonable alternative if you have a system that doesn't support Heads.

I still personally prefer the fact that Heads/PureBoot authenticate the host to your USB security token and think that's a bit stronger and more flexible.

I don't dispute that jails are hard to break into, but they are even harder to break out of. How many of us would choose to live in a prison in real life? Instead we make risk assessments that balance personal freedom and security, and the digital world should be no different.

The security industry has largely failed to build security measures without reducing a user's freedom more than attackers. It's not only harder to build security solutions that give users control, it reduces dependence on the vendor. This is why vendors just build jails.

@aral The problem is that the increased security in Apple products come at the cost of control. Security is the excuse but the goal is to limit the customer, not the attacker.

The rest of the industry also wants that control and buys into that security model and considers it the only way to do things.

We take a different approach prioritizing customer control, but it means rejecting many existing solutions and building new ones from scratch. We've made progress but not done yet.

@aral @claus We take a different approach for boot security with PureBoot because I don't believe in the control tradeoff you must make with verified boot and similar "jail vs jailbreak" solutions.

Any solution that depends on blocking binaries the vendor didn't sign anchors too much trust in the vendor and removes control from the user over what software they run.

@rbrown It would literally shock people.

It's pretty complicated all right...