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Joined 1 year ago
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Cake day: July 10th, 2023

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  • Otherwise monitors, cables and video cards would have compatibility issues.

    You’re right, and this was absolutely a thing. Video cards could produce whatever they were capable of, and monitors could display whatever they were also capable of. You could also push resolutions and refresh rates to monitors that was beyond the monitors’ specs, and you would also risk damaging the monitor by doing this.

    I don’t think you were pushing 4000x3000 resolution through VGA.

    You don’t need to believe me. That’s your choice. I had friends that could do the same. This was with a Matrox card and a 21" Acer CRT. The display was nearly impossible to read, and the color mask broke up the individual pixels too much, anyway.

    Just like today no one is pushing video streams to giant building sized screens over consumer HDMI or DVI.

    Digital video has upper limits in its specs. This is the whole point of this conversation.

    Another example is XLR VS 3.5mm jack. In theory you can push audio signal of any quality over both, but XLR by spec is balanced and shielded, while 3.5mm is not. This means that XLR is capable of pushing much better audio.

    A bit of incorrect information here. There is no “unshielded 3.5mm spec.” Good cables have shields, but not all. XLR doesn’t have the ability to transport higher frequencies because it’s balanced, or “much better audio.” On paper, unbalanced audio is better for short runs because there is more opportunity for XLR signals to have extremely minute signal quality issues due to the hot and cold signal mirroring, but it’s so small that it doesn’t matter.


  • In general, what is the highest frequency that can be carried over a wire?

    I know it can do these resolutions in practice because I have personally operated CRTs at 4000x3000 resolution in the early 2000s. This could be considered “the 4:3 of 4K.” It was not done on fancy equipment or high-end monitors. Analog stuff really could just go to really high resolutions and refresh rates with above-average, but typical stuff.

    CRTs simply respond to waveforms for red, green, blue, vertical sync, and horizonal sync. That’s it. If you want more horizonal pixels, make your scan lines denser. If you want more vertical pixels, add more scan lines. Want a faster refresh rate? Simply run all the signals faster.

    There is no hard upper limit to it. With digital signals, there are throughput limits per spec due to bit rates, but with analog, there are no bits. Resolutions like 40k x 30k are theoretically possible. The difficult parts are rendering the signal at these high frequencies, and being able to meaningfully display them. The VGA connection itself has no limits.



  • I wouldn’t want to reduce security by allowing privileged ports as any user, or running modified operating systems that have lessened security baked-in. This security principle is in place for good reasons, and they should remain in place.

    If you are exposing your LAN to your Internet connection, you’re doing something wrong. If you are not, but are using a firewall that doesn’t support NAT, then I don’t trust your firewall. If your firewall supports NAT, and you’re attempting to subvert Linux security measures instead of using it, then you’re doing something wrong.



  • The reason you can’t host as port 80 on unmodified Android isn’t because “Google won’t let you.” Android is open source. You can do what you want with it. Android runs on Linux, and ports 0-1023 are privileged ports that can only be used as root.

    Unmodified Android does not allow userland apps to run as root for very good reasons, so you don’t have access to these ports. That’s all there is to it. If you attempted to do the same thing on Ubuntu, you would also not be able to use port 80 without root.

    However, this is a naive approach to hosting a website. Production web stacks, when hosted on a machine, typically use a least-privileged model where not only ports are banned, but most file access is, too.

    Most dynamic web stacks won’t host on port 80 directly. Most will serve either a socket connection or host multiple ports on threads, i.e. ports 3000 to 3007. These connections would then be proxied via something like Nginx to serve as a load balancer, and Nginx can also manage SSL for you, too.

    If Nginx is started as root, it can host on port 80. If not, serve on port 8080 and use NAT to redirect it to port 80 with your firewall. You are using a firewall for publicly-hosted content, right?




  • Too many places let you drive if you do the happy path stuff right: stopping at a stop sign, changing lanes safely, etc. But the most important time of your driving is when you’re about to hit a semitruck and you need to get your car out of the way, and there is no training material for this at all. People often panic and slam the brakes and aggressively turn the wheel, which is a perfect setup for understeer and losing control of your car. They are literally getting in a situation where they are about to die and they choose to greatly increase their risk due to negligence.

    It’s cheaper to run simulators than purchase cars and hire trainers. Get em in nasty situations and teach them how to get out of it. For real, if mom and dad can’t evade sinking their freeway missile into a van full of kids, they shouldn’t be able to get behind the wheel and be presented with opportunities where this might happen any time they drive.




  • Don’t forget that Vim also keeps every tree of undo history. Wrote someone one way, wanted to try another way, and changed your mind? Switch to the other undo future! Change your mind again? Go back!

    And there’s persistent undo, where your undo history is written a file. Quit Vim, power off your machine for 5 years, power it back on, and you can still undo!