At some point there were LCD monitors that had very noticeable to me chequerboard pattern - like with analogue TV, only half of the screen got lit up/refreshed, but with an alternating pattern rather than scan lines.
After asking the owner of said screen how he could stand that... "stand what?"
It’s not necessarily picky - it’s sometimes about physically different perception.
When DLP projectors first came out, I couldn’t watch them. I would see colors breaking in fast motion scenes and whenever I would move my head even slightly (and … we all move our head slightly often when watching a movie).
When I told other people, some of them nodded in understanding, but the vast majority thought I was making things up - for them, it was a rock solid picture.
One of my friends replied: “I can see about 300hz. Not all the time - only when I have secadic movements; but that means many fluorescents, DLPs and other light sources drive me crazy. I guess you’re also a member of crazy club”
Some people can hear 26khz. Some people can see DLPs. Some people can see the alternating pattern….
I had a (regrettable) 19" 4x3 ViewSonic display that made that problem obvious -- way back in 2008 or so.
My homework at that time revealed a couple of things:
1. Liquid crystals are individually driven by AC waveforms, not DC as one might assume. This is the nature of the beast. The frequency at which the signal alternates is not necessarily very high. Thus, sometimes, this alternating nature is visible.
2. Some displays use dithering. A given display might support just -- say -- 6 bits per subpixel. To get the full 8 or 10 or whatever number of bits that are expected as a final output, the in-between steps are approximated by switching between two values -- sometimes (again) at a fairly low frequency that is visible.
...
But anyway, that ViewSonic monitor: Most people thought it looked fine, but it drove me nuts.
You'd better be, we have certain expectations from you now /s
But more seriously... I don't think that Linux has ever been booted on a non-monolithic CPU (I wanted to say 'discrete cpu' first, but there's some PDP-11s with 4 chip CPUs)
one could argue that 4004 is it. It does not really do memory ops at all. all decoding for memory ops happens inside the memory chips. but yeah - not non-monolithic enough
I'm by no means an expert, but I've recently implemented a small BLE based IoT device, and had a look at the security/privacy of a medical BLE device.
Some points:
* there's a real lack of quality, up-to-date documentation. I would have thought that at least on Linux you'd find some documentation, but most of it seems to be "RTFS".
* BLE is in general very unfamiliar to most developers. There's no client and server, there's central and peripheral. GATT profiles are a mix between TCP connections and binary REST-ish interface.
* Encryption/authentication is possible, but depending on the manufacturer's API/quality of documentation it's not really apparent a. how to select a secure connection method b. how to even check if and which authentication/encryption was chosen
* Coming from the previous point, many BLE devices have the same generic GATT profiles, sometimes with the same sample data. This looks like a lot of BLE devices just copy&pasted sample code from the manufacturer and added the minimal changes "to make it work"
* It's probably really easy to do passive/active fingerprinting to find out the manufacturer and/or chip version used in a device. Default services, ordering of advertising options etc
* Many BLE devices are not conformant. Uninitialised name fields with garbage in them ("Device Name: WHOOP\020��=u5״\023n"), manufacturers using random identifiers that clearly don't belong to them
* when doing passive BLE sniffing: the biggest obstacle isn't getting data. It's how to filter it. One of the most useful filters of the nRF Connect app for android is to filter out all advertisement packages for apple and ms devices, to cut down the overwhelming amount of such devices
There's plenty of options available. A coworker of mine used to print out code for reviews. You can use italic, bold and underline as alternative to colors. Grayscale might work nicely for eInk too - for laser printers just thin/regular/bold probably works better.
Other fonts... I could see myself being distracted by changing fonts in a document, except maybe for comment blocks. But for those italic/thin seems to work well already.
Tried to find the tool... it's GNU enscript. Syntax highlighting for several languages, outputs to postscript.
Source: https://www.theregister.com/2023/08/29/freebsd_boots_in_25ms...
reply