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April 12 2022 Magic-Wormhole, zram, lithium batteries and IT Stuff

Posted on April 16, 2022
( 3 minute read )

We met for the first time in two years at Bradford Community Broadcasting and also had our first hybrid meeting with Brian and John W online.

Brian asked a question about searching for someone when you have their last address but are not sure whether they are still there which generated a number of suggestions, none of which appeared conclusive.

He also mentioned that Magic-Wormhole, which he had talked about at the August 2019 meeting, now has a browser version allowing you to send files up to 10GB end-to-end encrypted.

John showed the 2007 Dell Latitude D430 notebook which he had picked up for under £100 to take with him on his bike and to use when he goes by train. It originally came with Windows Vista and has every connection you could want except HDMI. He uses the LXQt desktop with it. Brian asked about battery life and John said he got between an hour and an hour and a half but he rarely needed it when, for example, he was going on a train as he could plug it into the power supply. John mentioned that it was quite slow to start up as it only has 2GB RAM and Brian suggested installing zram which compresses memory — which John later did by placing the file zram.conf containing the line


in /etc/modules-load.d/.

Brian had considered using zram on the Raspberry Pi but decided not to as he did not fancy it making multiple writes to the USB.

Darren gave an update on his OU project to find out if the contents of two folders are identical and said that he had discovered that MD5 checksums were only identical if the files in the folders were in the same order. He now has to produce his second report on the project. He is continuing to work on his AI project looking at auto-encoders.

David, having shared the Youtube video on Scavenging rechargeable lithium cells from the roadside at the end of the last meeting, now produced a rather substantial discarded vape and proceeded to dismantle it as described in the video.

A lithium battery from a vape

This revealed the lithium battery which was labelled as a 3.7V 1500 mA battery. A test showed that it was still producing 3.29V.

In response to a question about IT Stuff, David said that it is now over partly because of a lack of volunteers and partly because, when it started, it was possible to report things which did not appear in the wider press until some time later. Now most things are appearing immediately. That does not mean we could not do something else to follow it up.