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2 yr. ago

  • And snapshot can benefit backup. Since some software need to be shudown to do backup, minimize the down time is important. The snapshot can make down time is almost stop and restart time, and the software can be online again and we can do backup on snapshot in background.

  • https://esp32-open-mac.be/ is working on reverse engineering ESP32 Wi-Fi hardware to implement a open source ESP32 MAC and PHY driver.

  • AFAIK, Mopria doesn't develop universal printing standards actually. The IPP standard was developed by Printer Working Group of IEEE. Of course, its members are almost same as Mopria. The standard Mopria developed is eSCL, a scanning standard. eSCL has a competitor, WSD, which was developed by Microsoft.

  • In fact, most manufacturers save money and don't shield the cable, forcing half-speed USB 1.1, which is enough for all mice and keyboards - less than 50 kb/s of the available 6 Mb/s is required even for 240Hz polling. High-end mice might have USB 3.0 (9 pins instead of 4 in the plug) but there should be no practical difference between 3.0 and 2.0 speeds.

    When speed is enough, latency became an issue. Although with 8kHz poll rate (USB 2.0 half-speed and full-speed can only get 1kHz poll rate), the latency will be 125µs at least. But for USB 3.0, it gained two ways to improve latency: 1) it can send Bus Interval Adjustment Message to adjust latency to 13.333µs (around 75kHz); 2) it can switch to async mode. Host no longer poll the device, instead, the device notify host via ERDY.

    Of course, I don't know how many devices utilized these features.

  • HM-SMR works better than normal DM-SMR, but it's rare and limit the filesystem choice: none on Windows and f2fs or btrfs on Linux.

  • Suggest use fsfreeze --freeze to block all access operation to create a stable image without unmount the SD card. (And release it later using fsfreeze --unfreeze.)

    BTW, this feature was created by XFS and was moved to VFS in Linux 2.6.29 so all filesystems supported by Linux gained this feature.

  • FYI, nvidia driver will remove shader cache that bigger than 1024MB. That make the game run without shader cache and has poor performance. Set environment variable __GL_SHADER_DISK_CACHE_SKIP_CLEANUP=1 to prevent this behavior.

    https://github.com/HansKristian-Work/vkd3d-proton/issues/2506

    Tips: Don't forget to search in issues of dxvk and vkd3d-proton when you meet game performance issue.

  • The big round corner is unbelievable ugly... at least in my opinion. If right angle is not popular in modern UI, the small round corner like in URL bar is acceptable to me, but this one is too huge...

    1. Thread and Zigbee use the same physical layer and MAC layer (IEEE 802.15.4), so in most case it can use the same hardware and just with different firmware (if manufacturer want).
      There is even a project to run both Zigbee coordinator and Thread border router on the same chip. It works! Although it causes some issue so Home Assistant no longer recommand this "multiprotocol" way, but this is a strong demonstration of the interchangeability between Zigbee and Thread.
    2. Thread Group members is almost the same companies who found Connectivity Standards Alliance (former Zigbee Alliance). When Connected Home over IP (CHIP) project was renamd to Matter at 2019, they create Thread Group to unify the home connectivity: Only use one network layer named IPv6 and one application layer named Matter. Zigbee can't reach this target since it use its own network layer and application layer. So they invent Thread, which still based on IEEE 802.15.4, but with IPv6 as network layer and can transport Matter on it.
  • Only GIMP can't cover all usages of Photoshop well. For image editing, GIMP is a good replacement; for painting, Krita is better.

    1. IPP Everywhere also include full autodiscovery stuff (mDNS and DNS-SD, of course, Apple call this combination as Bonjour). So I said raster is the only difference.
    2. Raster is unimportant in Linux situation because CUPS support both PWG Raster (It's actually a subset of original CUPS Raster) and Apple Raster. Whichever one your device supports, CUPS will work fine.
  • In anicent China, the writer and statesman Su Xun (蘇洵,苏洵) wrote a article named “On the Six Fallen States” (六國論, 六国论) about why the six states (韓、趙、魏、楚、燕、齊) were conquered by Qin (秦) during the Warring States period (戰國時代,战国时期)? The following is an excerpt from the relevant paragraph.

    今日割五城,明日割十城,然后得一夕安寝。
    One day five cities could be ceded, and on the next day, another ten cities could be surrendered just so that a certain person would have a single night of good sleep.
    起视四境,而秦兵又至矣。
    But in waking up and looking around, Qin troops again were approaching.
    然则诸侯之地有限,暴秦之欲无厌,奉之弥繁,侵之愈急。
    However, there was a limit to the available land of the lords and callous Qin’s avarice could never be satiated. The more there were giveaways, the more earnest Qin’s aggression would become.
    故不战而强弱胜负已判矣。
    So, even before going into battle, the odds-on-favorite and the most likely victor had already been decided.
    至于颠覆,理固宜然。
    As to the ultimate toppling, that was a forgone conclusion.
    古人云:“以地事秦,犹抱薪救火,薪不尽,火不灭。”
    Ancient people said: “Using land to serve Qin State would be like carrying firewood to put out fire. As long as there’s firewood left, the fire would not be extinguished.”

    In ancient, the six states use land to serve Qin state; in modern, the people use money to serve the companies provide subscription. The more people who pay for a subscription, the more power they have over price increases and control over your data.

  • I think network printer made by big manufacturer recent years should be fine with IPP driverless. They found Printer Working Group of IEEE, this organization maintains IPP standard and IPP Everywhere™ Certification. AirPrint can be treated as Apple version of IPP Everywhere, the difference between them is AirPrint requires Apple Raster but IPP Everywhere requires PWG Raster (and JPEG JFIF file format if color printer).

    https://www.pwg.org/ipp/everywhere.html

  • I'm looking for a Android SSH application with FIDO2 *-sk support. But I found none of them are open source and non-subscription. Termux is open source, it's good, but their libfido2 is unpatched so can't communicate with security key via USB or NFC on Android. ConnectBot is also great, but it lacks maintenance and doesn't support *-sk as well.

  • Choose the keyboard use QMK firmware or support VIA. Their configuration will be store in flash on keyboard permanently. VIA or QMK Configurator are just a "configuration writer".

  • and even without it, you'll get 150mA @ 5V by default out of the USB 3 host upstream and up to 900mA with some pretty basic USB negotiation in a protocol that dates from USB 1.0

    That's wrong. With USB Type-C, you can get the power up to 3A @ 5V with just two 5.1kΩ resistor on CC pins.