If you have a particular job focus for after you’ve graduated with your CS degree, would an internship with a related company be an option? Experience with web will be of limited use for an embedded job, and embedded experience is of limited use at a quantitative analysis company.
That’s not to say the experience is entirely pointless, since many skills across the various disciplines of CS are transferable.
If using asyncio is too impenetrable, try using Trio instead. It’s a sensibly-designed asynchronous library, to the point that you’ll find it’s easier to write non-trivial Python programs in Trio from the start, rather than bolting-on async support later.
Asyncio is just plain weird, IMO, exposing more low-level concerns than is customary for Python. Whereas Trio lets you get things done intuitively.
At least on my machine, that link doesn’t work unless I explicitly change it to HTTP (no S).
1 - I get that light is flashed in binary to code chips but how does it actually fookin work ? What is the machine emmiting [sic] this light made up of ?
This video by Branch Education (on YouTube or Nebula) is a high level explanation of every step in a semiconductor fab. It doesn’t go over the details of how semiconductor junctions work, though. That sort of device physics is discussed in this YouTube video by Ben Eater, “how semiconductors work”
2 - How was program’s, OSs, Kernal [sic] etc loaded on CPU in early days when there were no additional computers to feed it those like today ?
When the CPU powers up, typically the very first thing it starts to execute is the bootloader. Bootloaders will vary depending on the system, and today’s modern Intel or AMD desktop machines boot very differently to their 1980s predecessor. However, since the IBM PC laid the foundation for how most computers booted up for a nearly four decades, it may be instructive to see how it worked in the 80s. This WikiBook on x86 bootloading should be valid for all 32-bit x86 targets, from the original 8086 to the i686. It may even be valid further, but UEFI started to take off, which changed everything into a more modern form.
But even before the 80s, computers could have a program/kernel/whatever loaded using magnetic tape, punch cards, or even by hand with physical switches, each representing one bit.
But how does the computer decode this binary “machine code” into instructions to perform? See this video by Ben Eater, explaining machine instructions for the MOS 6502 CPU (circa 1975). The age of the CPU is not important, but rather that by the 70s, the basics of CPU operations has already been laid down, and that CPU is easy to explain yet non-trivial.
3 - I get internet is light storing information but how ? Fookin HOW ?
The mechanics of light bouncing inside a fibre optic cable is well-explained in this YouTube video by engineerguy. But for an explanation of how ones-and-zeros get converted into light to be transmitted, that’s a bit more involved. I might just point you to the Wikipedia page for fibre optic communications.
How the data is encoded is important, as this has significant impact on bandwidth and data integrity, not just for light but for wireless RF transmission and wireline transmission. For wireless, this Branch Education video on Starlink (YouTube or Nebula) is instructive. And for wired, this Computerphile YouTube video on ADSL covers the challenges faced.
Quite frankly, I might just recommend the entirety of the Computerphile channel, particularly their back catalogue when they laid down computer fundamentals.
4 - How did it all come to be like it is today and ist it possible for one human to even learn how it all works or are we just limited one or two things ? Like cab we only know how to program or how to make hardware but not both or all ?
As of 2024, the field is enormous, to the point that a CompSci degree necessarily has to be focused on a specific concentration. But that doesn’t necessarily mean the hard stuff like device physics are off-limits, leaving just stuff like software and AI. Sam Zeloof has been making homemade microchips, devising his own semiconductor process and posting it on YouTube..
Specifically to your question about either software or hardware, the specialty of embedded software engineering requires skills with low-level software or firmware, as well as dealing with substantial hardware-specific details. People that write drivers or libraries for new hardware require skills from both regimes, being the bridge between Electrical Engineers that design the hardware, and software developers that utilize the hardware.
Likewise, developers for high performance computers need to know the hardware inside-out, to have any chance of extracting every last bit (pun intended) of speed. However, these developers tend to rely upon documentation such as data sheets, rather than having to be keenly aware of how the hardware was manufactured. Some level of logical abstraction is necessary to tractably understand today’s necessarily large and complex systems.
5 - Do we have to join Intel first or something to learn how most of the things work lol ?
Nope! Often, you can look to existing references, such as Linux source code, to provide a peek at what complexities exist in today’s machines. I say that, but the Linux kernel is truly a monster, not because it’s badly written, but because they willingly take code to support every single bleeding platform that people are willing to author code for. And that means lots and lots of edge cases; there’s no such thing as a “standard” computer. X86 might be the closest to a “standard” but Intel has never quite been consistent across that architecture’s existence. And ARM and RISC-V are on the rise, in any case.
Perhaps what’s most important is to develop strong foundations to build on. Have a cursory understanding of computing, networking, storage, wireless, software licenses, encryption, video encoding/decoding, UI/UX, graphics, services, containers, data and statistical analysis, and data exchange formats. But then pick one and focus on it, seeing how it interacts with other parts of the computing world.
Growing up, I had an interest in IT and computer maintenance. Then it evolved into writing websites. Then into writing C++ software. Right before university, I started playing around with the Arduino’s Atmel 328p CPU directly, and so I entered uni as a Computer Engineer, hoping to do both software and hardware.
The space is huge, so start somewhere that interests you. From the examples above, I think online videos are a fantastic resource, but so can blog posts written by engineers at major companies, as can talks at conferences, as can sitting in at university courses.
Good luck and good studies!
I vaguely recall a (probably apocryphal) story of an early washing machine-sized hard drive that lurched its way across the floor during a customer demo, eventually falling over once the connecting cables pulled taught.
That said, those hard drives did indeed move themselves: http://catb.org/jargon/html/W/walking-drives.html
I think this can be more generalized as: why do some people eschew anonymity online? And a few plausible reasons come to mind:
IMO, older people tend to have the first reason, having grown up with the Internet as a communication tool. Younger, post-2000 people might have the second reason, because from the events during their lifetime, privacy has eroded to the point it’s almost mythical. Or that it’s like the landed gentry, that you have to be highly privileged to afford to maintain anonymity.
I have no thoughts as to the prevalence of the third reason, but I’m reminded of a post I saw on Mastodon months ago, which went something like this: every village used to have the village idiot, but was mostly benign because everyone in town knew he was an idiot. One moron in every 5 or 10 thousand people is fine. But with the Internet, all the village idiots can network with each other, expanding their personal communities and hyping themselves up to do things they otherwise wouldn’t have found support for.
Coming back to the question, in the context above, maybe online anonymity is a learned practice, meaning it has to be taught and isn’t plainly natural. Nothing quite like the Internet has ever existed in human history, so what’s “natural” may just not have caught up yet. That internet literacy and safety is a topic requiring instruction bolsters this thought.
I may be confused, but is this a common endeavor? I have used xxd -i before, but have never found its speed of operation lacking.
It’s for this reason I sometimes spell out the Bytes or bits. Eg: 88 Gbits/s or 1.44 MBytes
It’s also especially useful for endianness and bit ordering: MSByte vs MSbit
The knot is non-SI but perfectly metric and actually makes sense as a nautical mile is exactly one degree meridian
I do admire the nautical mile for being based on something which has proven to be continually relevant (maritime navigation) as well as being brought forward to new, related fields (aeronautical navigation). And I am aware that it was redefined in SI units, so there’s no incompatibility. I’m mostly poking fun at the kN abbreviation; I agree that no one is confusing kilonewtons with knots, not unless there’s a hurricane putting a torque on a broadcasting tower…
No standard abbreviation exists for nautical miles
We can invent one: kn-h. It’s knot-hours, which is technically correct but horrific to look at. It’s like the time I came across hp-h (horsepower-hour) to measure gasoline energy. :(
if you take all those colonial unit
In defense of the American national pride, I have to point out that many of these came from the Brits. Though we’re guilty of perpetuating them, even after the British have given up on them haha
An inch is 25mm, and a foot an even 1/3rd of a metre while a yard is exactly one metre.
I’m a dual-capable American that can use either SI or US Customary – it’s the occupational hazard of being an engineer lol – but I went into a cold sweat thinking about all the awful things that would happen with a 25 mm inch, and even worse things with 3 ft to the meter. Like, that’s not even a multiple of 2, 5, or 10! At least let it be 40 inches to the meter. /s
There’s also other SI-adjacent strangeness such as the hectare
I like to explain to other Americans that metric is easy, using the hectare as an example. What’s a hectare? It’s about 2.47 acre. Or more relatable, it’s the average size of a Walmart supercenter, at about 107,000 sq ft.
1 hectare == 1 Walmart
I’m surprised there aren’t more suggestions which use intentionally-similar abbreviations. The American customary system is rich with abbreviations which are deceptively similar, and I think the American computer memory units should match; confusion is the name of the game. Some examples from existing units:
I’m afraid I have no suggestions for DoT servers.
One tip for your debugging that might be useful is to use dig to directly query DNS servers, to help identify where a DNS issue may lay. For example, your earlier test on mobile happened to be using Google’s DNS server on legacy IP (8.8.8.8). If you ran the following on your desktop, I would imagine that you would see the AAAA record:
dig @8.8.8.8 mydomain.example.com
If this succeeds, you know that Google’s DNS server is a viable choice for resolving your AAAA record. You can then test your local network’s DNS server, to see if it’ll provide the AAAA record. And then you can test your local machine’s DNS server (eg systemd-resolved). Somewhere, something is not returning your AAAA record, and you can slowly smoke it out. Good luck!
If I understand correctly, you’re now able to verify the AAAA on mobile. But you’re still not able to connect to the web server from your mobile phone. Do I have that right?
I believe in a different comment here, you said that your mobile network doesn’t support IPv6, and nor does a local WiFi network. In that case, it seems like your phone is performing DNS lookups just fine, but has no way to connect to an IPv6 destination.
If your desktop does have IPv6 connectivity but has DNS resolution issues, then I would now look into resolving that. To be clear, was your desktop a Linux/Unix system?
If you describe what you configured using DNS and what tests you’ve performed, people in this community could also help debug that issue as well.
An AAAA records to map a hostname to an IPv6 address should be fairly trouble-free. If you create a new record, the “dig” command should be able to query it immediately, as the DNS servers will go through to the authoritative server, which has the new record. But if you modified an existing record, then the old record’s TTL value might cause the old value to remain in DNS caches for a while.
When in doubt, you can also aim “dig” at the authoritative name server directly, to rule out an issue with your local DNS server or with your ISP’s DNS server.
Could you let us know what the DNS issue was?
I’m not quite sure I follow. The AGPL mirrors the GPL, with an extra proviso that accessing the software via the network constitutes “use” if the binary, not “distribution” of the binary. Under GPL, the mere use of a binary does not require the availability of source.
Example: a student uses a GNU/Linux computer at their university computer lab. She runs the unmodified “tar” command from GNU Coreutils, which is GPL licensed. She is not entitled to a copy of the source from the university, because execution is a “use” of the binary on an already-provisioned machine, not a “distribution” of the binary.
Example: a student is given a software assignment from her professor, along with a .7z file containing old versions of “tar” that contain bugs, all GPL licensed. This is a distribution – as in, a copy – of the binary, so she is entitled to a copy or link to the source from her professor.
The first example helps explain what the AGPL adds, in the context of network use. Consider what happens if the university actually modified the “tar” command installed on their machines. They still would not have to distribute the modified source to the students, because students only execute (“use”) the binaries. But with AGPL, use of modified software obliges source distribution.
Phrased another way, AGPL has every guarantee that GPL does, but adds another obligation for modified use via a network. Unmodified use does not require source distribution, under both GPL and AGPL.
One of the drawbacks of software licensing with community projects – although there are some (controversial) ways to sidestep this – is that the license needs to be selected at the onset of the project, and you’d have to have everyone agree to that license or change the license.
If all the initial parties agree to use a FOSS license, they and all subsequent contributors under that license cannot complain that someone is actually employing that software per the terms of the license. A project might choose FOSS because they want to make sure the codebase only dies when it disappears from the last developer’s disk.
If instead, the initial parties decided on some sort of profit-sharing license – I don’t know one of the top of my head – then they and future contributors cannot complain if no business wants to use the software, either because FOSS competitors exist or because they don’t like the profit split ratio in the license. If that ratio is fixed in the license, the project could die from lack of interest, since changing the license terms means everyone who contributed has to agree, so a single hardliner will doom the already-written code to obscurity.
The sidestep method – which is what appears to have been used by Redis to do this relicensing to the SSPL – is that all contributors must sign a separate agreement giving Redis Inc a stake in your contribution’s copyright. This contributor agreement means any change to the Redis codebase – since its inception? Idk – has been dual-licensed: AGPL to everyone, and a special grant to Redis Inc who can then relicense your work to everyone under a new license.
Does the latter mean Redis Inc could one day switch to a fully-closed source license? Absolutely! That’s why this mechanism is controversial, since it gives the legal entity of the project all the copyright powers, to level-up to FOSS or level-down to proprietary. Sure, you can still use the old code under the old license, but that’s cold comfort and is exactly why hard forks of Redis are becoming popular right now.
In short, software projects have to lay out their priorities at the onset. If they want enduring code, that’s their choice. If they want people to pitch in a fair share, that’s fine too. But that choice entails tradeoffs, which they should have known from the start. Some mechanisms allow the flexibility to change priorities in the future, but it’s a centralized, double-edge sword.
There are two concepts at play here: open-source and free software. An early example of open-source is AT&T Research UNIX, which was made source-available (for a few) to universities for research purposes, who could recompile the code and use the binaries for that purpose. Here, the use of the software is restricted by the license terms.
On the free software side, as a reimplementation if the Unix software utilities – ie all the programs like tar, ps, sh – GNU coreutils is GPL licensed, meaning any use of the compiled binaries is allowed, but there are restrictions on the distribution, of both source and binaries. As it turns out, GPL is both free and open-source (FOSS); there are fewer major examples of free but non-open source, but WinRAR and nVidia drivers on Linux would count.
Specifically, GPL and other copyleft licenses require that if you distribute the binary, you must make the source available under the same terms. If you’ve made no changes, then this is as simple as linking to the public source code repo. If you did add or remove code, you must release those alongside the binaries. If you simply use the binaries internally, you don’t need to release anything at all, and can still use them for any internal purpose.
wouldn’t GPL and other copyleft licenses be considered non-free as well since you are not free to do whatever you want with the source
From the background above, free software has always been understood to mean the freedom to use software, not necessarily distribute it. GPL complies with that definition for using the software, but also enforced a self-perpetuating distribution requirement. Unlike plain ol free software, under GPL, you must redistribute source if you distribute the software for use (aka binaries), and you must make that source also GPL.
Irrespective of debates on what the definition of “open source software is” or who gets to define it, it is very clear that the SSPL is not a FOSS – free and open source license – and that’s a shame. Sure, open source still means we can look at the source code, but we do not have the full freedoms to use the code for any purpose. You might retort “but I’m not a aaS provider” so my rights aren’t affected.
But that’s the thing: the erosion of free software rights is never the end, but then beginning of the end. Much like free speech, such rights must be jealously guarded. Need I mention what happens when there’s no one left to speak up?
That some users of Redis never contributed back to the project is beside the point: truly free software is free as in libre: if you want thanks for your work, release it as freemium or some other license. But a FOSS license like BSD-3 has always been thankless and the OSI is correct in calling out the SSPL for not meeting the OSI’s Open Software Definition’s anti-discrimination clause, nor the FSF’s zeroth freedom, amongst four.
Free means free. AGPL is free. But SSPL carves out an exception, making it not free. No amount of sweet talking changes this reality.
I’m not a Rust developer (yet), but I understand its strength in this regard as: Rust is statically memory safe by default, and code which isn’t statically memory safe must be declared with the unsafe keyword. Whereas C++ has not deprecated C-style pointers, and so a C engineer can easily write unsafe C code that’s valid in a C++ compiler, and no declaration of its unsafeness is readily apparent to trigger an audit.
It’s nice and all that C++ pioneered a fair number of memory safety techniques like SBRM, but the debate now is about safety by default, not optional bolt-on safety. All agree that the overall process to achieve correct code is paramount, not just the language constructs.
This checks out lol
I often wonder if this deep level understanding of embedded software/firmware design is still the norm in university instruction. My suspicion has been that focus moved to making use of ever-increasing SoC performance and capabilities, in the pursuit of making it Just Work™ but also proving Wirth’s Law in the process via badly optimized code.
This was an excellent read, btw.