robryk @robryk@qoto.org

@robryk@qoto.org Removed bounding wires are pretty common in these photographs. It's often difficult to extract the chip without touching the wires.

Also another fun fact, LTZ1000's technology came from another legendary LT chip - LT1088 RMS-to-DC converter, this is where the unused heaters were used from. LT1088 measures True RMS voltage by AC-DC thermal conversion. The input AC power is dissipated into an on-chip resistor, and you heat another on-chip resistor using DC power until both reach the same temperature, this is the very definition of RMS voltage. It's still the holy grail in metrology labs, and also standard for RF/microwave power measurements. But as far as I know, the LT1088 was the only attempt to do this in an off-the-shelf chip. Too bad it was never a commercial success and went out of production.

Mt. Rainier casting a shadow upwards across the sky.

This is really quite fascinating. There is exactly one ISP that is blocking mail from the mail server I run, which is used to deliver mail for infosec.exchange - t-online.de. It annoys me to no end that I see people try to subscribe to infosec.exchange and the confirmation emails are rejected. So, I contacted their postmaster, and to their credit, they got back to me very quickly, but they are basically saying "yeah, you need to use one of the big mail providers if you want to send mail to t-online subscribers".... Ok then. My apologies to any t-online subscribers (who probably can't see this anyhow), but you'll apparently need to use a different email account to register.

So, don't tell anybody, but we're going to announce Palm Pilot emulation in the browser at Internet Archive in the next week or so. I've still got to get descriptions in for the hundreds of apps that are uploaded, and add a few more classics. But if you want to help with that, or just let me know how it's going, ping me here.

But don't tell anybody! It's a secret!

https://archive.org/details/softwarelibrary_palm

@robryk@qoto.org Yes. You can measure temperature by observing a crystal oscillator's frequency drift (with a known reference clock). Hewlett-Packard made this lab instrument in the 1960s, with a resolution of .0001”C. AFAIK it's still a really precise method by today's standard, but it went out of favor as the crystal needs to have a special cut with linear temperature coefficient. See HP Journal Vol. 16, No.7, 1965. http://hparchive.com/Journals/HPJ-1965-03.pdf Linear Technology App Note 61 shows how to build your own, see page 13: https://www.analog.com/media/en/technical-documentation/application-notes/an61fa.pdf

Fun fact: This phenomenon has been used as a deanonymization attack against Tor. By observing the 24-hour drift of the system clock, one can determine the longitude of the target server, latitude can further be determined by the change in day length. https://www.freehaven.net/anonbib/cache/HotOrNot.pdf

#TIL Möbius resistor. Take a double-sided copper tape (with its top insulated from the bottom), and join the tape onto itself as a Möbius strip. Now you get an ideal current-sensing resistor with almost no parasitic inductance. The resistor behaves like two short-circuited microstrip transmission lines with continuous ground planes, with an input port always at the center. An extreme form of the "folding back the wire" technique for making non-inductive wire-wound resistors... Cool idea, but practically it probably isn't too useful... https://en.wikipedia.org/wiki/M%C3%B6bius_resistor #electronics

Foxes in Love 11/14/2022
homepage: https://foxesinlove.net
source: https://foxes-in-love.tumblr.com/post/700889032447705088