I was thinking about how I used a cheap VPS in the past to "temporarily" host something for Lemmy for fun.
Well, our instance had major issues, and a data loss, making me loose access to those comments and post. And I didn't get a domain name, because it was "temporary" anyway.

Now, whoever inherits 167.160.186.15 can embed something else into 2 of my comments and 1 post.

Anyway, this is also the case of hosts like catbox.moe. Perhaps it dies one day, and instead of original images, something malicious will be returned.

A thought genuinely produced in the shower.

What happened

I didn't pass enough subjects. To study there again, I'll have to go through regular admission procedure again, but it's too late to sign up for next year.

Passed subjects acceptance

Like other colleges, the one I went to accepts passed subjects from previous studies. So if you studied at a different college and passed the same subjects (within past x years), you don't have to re-do them.

However, unlike with the others I checked, our college will only accepts subjects passed at A or B. This probably makes sense, as they might not trust other colleges to hold students up to the same standards.

This means that I'll have to retake the subjects I already passed.

Idea 1 - immediate transfer request (not possible)

Not wanting to wait a year, I hoped to go to different college of the same university, and ask for transfer right after registration. (If rejected, idea 2)

Unfortunately, the university's rules only permit transfers within the same field, and the same one is not available to sign up for anymore.

Idea 2 - Piggyback on different college for a year

There are 2 colleges on the same university that still accept students and offer housing on a dorm in the same city.
The university rules also permit students to change their study plans, with possibility of registering subjects on different colleges of the same university.

Thus my idea was to officially "attend" College of Mechanical Engineering (which is desperate enough to have no entrance exams), withdraw from all their subjects, and register relevant subjects on College of Informatics.

I asked the study department about my plan. They confirmed it should be possible, but the A/B grading requirement remains.

How does that make sense?

I could take their subjects at their own college, pass them by their own standards, yet they themselves wouldn't accept them.

Alternatively, I could attend an easier college with lower standards, spend less effort for A/B, and pass just the same.

Alternative ideas

Only idea 1 makes sense economically (if the request got accepted), as otherwise I'd pay for 2 extra years rather than just one.
That sucks, I wished to basically go "hey, I am still here like a cockroach".

So to stay here, it's best to just get a job for a year and try not to loose too many fingers (all I found in my location with provided training and no required education is "plastic press operator" or "metal machinist").

Or give up, and study a different field.

I haven't ran this for a few months, so I may not remember everything I had to set up.

Anyway, it's just regular install of Proxmox that I then installed KDE Plasma on top of (same as with plain Debian).
I had to remove WiFi interface from /etc/network/interfaces for it to work as expected.
I also set up NAT for guests (10.0.0.0/24) (lower middle in screenshot).
To guests I added vhost-vsock-pci to make Vsock work (used for Waypipe), and VirtIO sound card to make audio work through host. (Under args: in middle of screenshot). You can see audio show up in Applications tab of sound menu (bottom right), currently playing music from Debian's Firefox Window (top, slightly left).
Waypipe is set up to automatically listen on host using KDE's Autostart menu (bottom, center). Applications are launched using desktop shortcuts which send a command to guests over SSH (middle, slightly left).

One thing you may notice is app icons not working (Wayland icon is shown instead). I don't know why, it only works for LibreOffice. But that's just cosmetic.

End result is that aside from guests not having HW acceleration for thing like video playback, things just work like with normally installed programs. Double-click an icon, and it launches.

I haven't set up anything nicer for storage. SSH is sub-optimal due to useless encryption, but for the occasional 5MiB file this doesn't matter.

One thing I am not sure how to do "properly" is Waydroid. I tried to set it up in unprivileged Arch LXC, that did not work. I could just put it directly onto host, but that feels wrong. And inside a VM I can't use GPU acceleration, which even on a more powerful machine was a quite painful experience.

I am not talking about the obviously cheap Temu items that are made for 1 use before disposal or burial in a hoarder's house.

Instead it's about electronics which seems nicely made until "oh, what the fuck is this".

Some examples:

Other electronics

RFID scanner with permanently half-pressed button

If testing for "does it work" was all they did, then yeah, it passed. But the plastic housing was too narrow for the button, causing it to be mostly pressed. Even just touching the housing elsewhere would make that register as button press.

Speakers/earphones that scream "low battery" at full volume

Not much to comment here. I bought some earbuds, and got a nice midnight shock when they did that.

Screwing into plastic

I've got a 5.25" drive enclosure. Taking it apart, I was pleased. For the outer metal sheets they put metal inserts into the inner plastic for the screws.
And then the thing that actually holds some weight is tapered holes in brittle plastic for mounting the drive.

Lack of insulation

I've got an IDE to SATA adapter. Sounds like a piece of electronics that needs some thought to design.
And... what the fuck, the power connector leads are only separated from touching metal by a thin piece of foam tape they will puncture soon.

Badly designed phone cases

At this point I just expect to need a knife to fix them.
2 phones back I had to cut a lager hole for the headphone jack.
With previous phone I had to cut down some of the silicone (?) to reach side-mounted fingerprint scanner.
With current phone I had to cut off the entire camera lens protector part as it was conducting light from flash back to the lens.

Smartphones

And now the main part.

There are a few brands that manufacture unique phones such as Doogee, Unihertz, Ulefone, etc.
There's also many devices with pretty powerful hardware for a great price.

But the software...
Seems to frequently be a very buggy experience. Also, previously I had a Poco which had ads throughout the UI.
Oh, and there's a chance for pre-installed malware.
Anyway, for the bugs, it's things like random restarts, partial system crashes, and it seems even a chance of bricking on update.
If you check reviews from people online, you'll figure out one thing quickly: if the software currently works at a usable level, DO NOT UPDATE EVER AGAIN.
Oh, one of the more important bugs was reversed L/R channels for microphones on the Poco.
Speaking of audio, my Ulefone has really crappy audio post-processing, so the only way to get usable audio is to use "Unprocessed" audio source in Open Camera, and then edit the audio appropriately in Audacity.
Anyway, the list of bugs would be quite long.

What really sucks, is the lack of custom ROMs since these devices tend to be MediaTek-based.
And I really hate that as there's so much interesting hardware with crappy software.
If you haven't seen them, they have really tiny devices, devices with huge batteries (like 25,000mAh large) that look like bricks, phones with keyboards, massive speaker, extra strong lights, even built-on projectors, etc.

This feels odd to explain, but there's 4 main scenarios:

1. There's too much stuff I have to do

I just get overwhelmed. I don't know where to start. What do I do first? I must start right away, but how?
If I pick one thing to do first, the knowledge of other ones keeps taking my focus, and I just end up doing nothing and panicking.

2. There's just something I have to do

Absolutely anything will suddenly seem interesting. I am supposed to study math?
How about getting back to Meteor LRPT reception? What about checking out the TETRA signal in your location? Installing Proxmox on a laptop, sure thing. Yes, now is the time to read datasheet of NTAG NFC tags and try out manually sending the commands in hexadecimal. What's math, let's start studying railroad regulations. Meshcore? Hell yeah, let's join the network.
etc...

3. There's nothing to do

Sounds like the time for my interests. But now, nothing comes to mind. Nothing sounds interesting. Absolutely nothing. I don't want to waste time, yet at the same time I don't want to... anything.
Even just getting dressed up feels like dragging my soul across sharp rocks.

4. Deadline is approaching FAAAAAAAST

Oddly, in some way the best scenario. I can finally get myself to be productive, and it even feels good. I see what I did, I see I spent the time well, I can focus.
One good example, an assignment I managed to do shortly before deadline. I put in 16 hours at once, only leaving to the toilet. I finished it at 4am before waking up at 7am, yet, I felt satisfied.
However, one "bad" thing that can happen here is "deadline extended by one week" if I cannot manage it. Suddenly, I loose that feeling of urgency, and slip back into scenario 2.

Bonus: Everything is a distraction.

I occasionally see people recommend putting your phone away, disabling notifications, etc...
Cool, cool.
However, I often get distracted by things like... the pen and paper. Look at that beautiful ink being transferred to the sheet of paper.
But hell, you can remove any physical objects, but you can't remove thoughts. I am listening, I am focused, and oh fuck, there goes a 10 minute imaginary conversation.
OK, I need to do better. Focus, listen, read, think, focus, listen, read,... great, I am focusing on focusing itself.

And lastly, ever heard of /dev/null? My brain pipes to it fairly often. Past 5 minutes? Never heard of them.
I can re-read something 3 times, and just immediately forget what the hell that was.
I can think of something, make the slightest physical movement, and it's gone.
I can listen to someone, process it, answer, immediately forget what I just answered to.

I found this app: https://f-droid.org/en/packages/com.nfcarchiver.nfc_archiver/

This interested me as I like the idea of storing larger amount of digital data on unusual mediums, like Optar which was a program to store data on paper.
But in the end, when I checked its GitHub after finding some issues, I found this:

Anyway.
2 minor issues are that compressed size is only estimated, even though it will never work with more than a few MB at best (62.13MB).
Second, it also doesn't tell you when the max size is exceeded at first, only when you try to make the archive. Additionally, the max size isn't mentioned.

Based on the documentation, which is also partially incorrect, the limit is probably 2^16^ chunks.

And now the main issue - fitting 76B into 48B of memory

I am just a random dumb person, so I may have made some mistakes too.
Anyway, I noticed that selecting the MIFARE Ultralight option does nothing in the app:

Notice how at the bottom data from previous option is kept.
But why?

This part of docs will be useful:

First of all, I find the format quite inefficient for something with so little storage.
1 whole byte for 2 bits of data? (compression/encryption flags)
Motherfucking 16 byte ID? (when the smallest "supported" medium is 48 bytes)
Notice how the documentation accounts for ~38 byte overhead (which already excluded the mentioned CRC).
Now, let's open this file: https://github.com/mezinster/nfcarchiver/blob/master/lib/core/constants/nfar_format.dart

/// Header field sizes in bytes
abstract class NfarHeaderSize {
  static const int magic = 4;
  static const int version = 1;
  static const int flags = 1;
  static const int archiveId = 16;
  static const int totalChunks = 2;
  static const int chunkIndex = 2;
  static const int payloadSize = 2;
  static const int crc32 = 4;

  /// Total header size (without payload)
  static const int total = magic +
      version +
      flags +
      archiveId +
      totalChunks +
      chunkIndex +
      payloadSize +
      crc32;
}

The total is 32.
Now for NDEF:

int get maxPayloadSize {
    // NDEF overhead includes:
    // - NDEF record header: 3-6 bytes (flags, type length, payload length)
    // - MIME type: 33 bytes ("application/vnd.nfcarchiver.chunk")
    // - NDEF TLV wrapper: ~5 bytes
    // Total NDEF overhead: ~41-44 bytes
    // We use 44 bytes as a safe margin
    const ndefOverhead = 44;
    final available = capacity - ndefOverhead;
    return available - NfarHeaderSize.total;
  }

So that's statically defined as 44 bytes. Together, that's 76 bytes. If you look at the earlier screenshot, having previously selected 888B tag, the usable size is shown as 812B. 888 - 812 = 76
So that checks out.

So, if the tag capacity is 48, we end up with -28. Negative available storage, nice.

At least this commit mentions the previous assumption of 10 bytes.

Also, there's this bit:

/// Minimum supported tag capacity
  static const int minTagCapacity = 64;

So if I understand this all correctly:

1. Smallest "supported" tag type is 48B
2. The code defines smallest supported size as 64B
3. The format has a 76B overhead

What?

Alt link if the image isn't loading: https://files.catbox.moe/pb85zm.JPG (this one didn't embed)

The top image is obvious.
In the bottom one, sharp leads from the 12V+5V power connector end up getting pressed against metal, only being separated by a thin piece of foam tape (so someone did recognize the issue, huh?).

I thought of ordering it together with an IDE extender, but "nah, I won't need it."

...or whatever remains of it?

Yeah.
I finally found what I was searching for, usage of RW media similar to DVD-RAM. Only to find it's been removed from Linux Kernel: https://www.phoronix.com/news/Linux-To-Remove-pktcdvd

Worry not, something remains: https://www.kernel.org/doc/html/v6.1/cdrom/packet-writing.html

According to the DVD+RW specification, a drive supporting DVD+RW discs shall implement “true random writes with 2KB granularity”, which means that it should be possible to put any filesystem with a block size >= 2KB on such a disc.

And indeed, with DVD+RW disc, I can just do so. Even if it's really sub-optimal.

However, some drives don’t follow the specification and expect the host to perform aligned writes at 32KB boundaries. Other drives do follow the specification, but suffer bad performance problems if the writes are not 32KB aligned.

Anyway...

ext4 on DVD

So, yes. After initial format, I can just

mkfs.ext4 -b 2048 /dev/sr0

Might have been a coincidence as I just used an old disc and failing drive, but trying block size of 4096B made formatting extremely slow. No wonder, after inspecting the disc, it was clear the formatting fully re-wrote it, which didn't happen with 2048B BS.

tar

That worked as well. Exact command I used:

tar -vcf /dev/sr0 -b 4 files/

I am not sure if my setting for blocking factor made any sense whatsoever. I didn't retry this. As I said, old disc and drive. It would work in bursts, then get stuck for a long time. Writing ~500MB took roughly an hour.
Reading it worked well though.

Who needs an FS when you have tar.

Partition table on DVD - where the dreams fall apart

fdisk /dev/sr0

That... worked. I created GPT and added 2 partitions. After writing the changes, I reinserted the disc.
Aaaaaand... nothing.

You can see that there is indeed a GPT on that DVD+RW, which feels crazy. But, where are my partitions?
Looking in /dev, I found no mention of partitions.

ls /dev/sr0*
/dev/sr0

Let's check fdisk again:

fdisk -l /dev/sr0
Disk /dev/sr0: 4.38 GiB, 4700372992 bytes, 2295104 sectors
Disk model: DVDRAM GH24NS90
Units: sectors of 1 * 2048 = 2048 bytes
Sector size (logical/physical): 2048 bytes / 2048 bytes
I/O size (minimum/optimal): 2048 bytes / 2048 bytes
Disklabel type: gpt
Disk identifier: 6AE020A5-1F51-46A6-8741-C28915AF6208

Device      Start     End Sectors  Size Type
/dev/sr0p1    512  524799  524288    1G Microsoft basic data
/dev/sr0p2 524800 2294783 1769984  3.4G Linux filesystem

Hmmm. I didn't use root, so I got a hint from fdisk. I did re-insert the disc, so it should've been irrelevant now, but at least it pointed me to a potentially useful command.

# The kernel still uses the old table. The new table will be used at the next reboot or after you run partprobe(8) or partx(8).

sudo partx -av /dev/sr0
partition: none, disk: /dev/sr0, lower: 0, upper: 0
/dev/sr0: partition table type 'gpt' detected
range recount: max partno=2, lower=0, upper=0
partx: /dev/sr0: adding partition #1 failed: Invalid argument
partx: /dev/sr0: adding partition #2 failed: Invalid argument
partx: /dev/sr0: error adding partitions 1-2

Invalid argument?
Does it mean I can't load a partition table from a DVD?

LVM to the rescue? (no)

Short answer in this case:

sudo pvcreate -v /dev/sr0
  Cannot use /dev/sr0: device type is unknown

Finally at last, a disc directly playable with aplay

Obviously, I can write bytes to the disc, so this isn't special. But it feels cool.
I find it unfortunate that I can't simply take data of audio CD, playing it with aplay. But now I can at least do so with a DVD.

ffmpeg -i Stan\ LePard\ -\ Velkommen\ \(1996\).wav -f s16le -acodec pcm_s16le -ar 44100 -ac 2 tmp/velkommen.raw

And writing with dd

dd if=tmp/velkommen.raw bs=2048 status=progress of=/dev/sr0
57145344 bytes (57 MB, 54 MiB) copied, 16 s, 3.6 MB/s
27930+0 records in
27930+0 records out
57200640 bytes (57 MB, 55 MiB) copied, 33.49 s, 1.7 MB/s

It might be good to know this got stuck the first time at the end. So I used truncate to pad it with zeros to a multiple of 2KiB. Again, might have been a coincidence (sample size 2).

And finally, the dream is achieved:

aplay -f cd /dev/sr0
Playing raw data '/dev/sr0' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo

Now I could perhaps try to make a script/program which would take list of files, convert them to raw PCM, record track byte offsets and other data (like track title), concatenate the audio, add the info data in some specific format, and also have a program/script to read the info and play the tracks!

Re-inventing the ~~wheel~~ disc.

I guess it's obvious why I am asking.

I am just too dumb for it. Like, genuinely. I only passed through HS because on final exam from literature the teacher gave me a full answer. Actually, I didn't even get that, she had to tell me "Write that down!" because I was just thinking "Why are you telling me that?"

In 1st semester I didn't pass 2 subjects. Now in 2nd one I only got to final exam of 1, which I'll have to retake and I don't feel like I'll pass it either. The only subject I was really interested in passing I didn't manage to get through due to me being late with assignments.
I am still planning to finish the last one just because I want to get rid of my Firefox tabs and I already spent 32 hours on it. The previous one took me 50 hours only for partially completing it. I estimate full completion at 65 hours, if I did that one, which I may do as well later.

Which isn't much time, actually. When I do the math based on credits, main part (time until exams) of first semester being 12 weeks, second 13 weeks, it averages out at 61h/week of work (combined lectures + seminars + expected study time and assignments).
2nd semester at 52h/week
1st semester at 71h/week.

Regardless of how I manage the exam, I won't pass to the second year.

Oh, it gets worse. I found out I was supposed to select my subjects for next year. They only sent us the email about that the day prior (2pm).
I skimmed it, OK, selection starts June 4th, went to check the UI, nothing there. Turns out, the selection deadline was on that same day, at 9pm, so I missed it by 3 hours.
Worse yet, though not applicable to me, the school also "thinks" of foreign students. In this case by notifying them only 12 hours before the deadline as well as informing them that the information in English is outdated (and that's all they did about it).

It's album named Virgin from Lorde. Not quite my taste of music, but the disc itself is pretty interesting.
Though it does have issues. Since the reflective layer is very thin, a lot of light passes through.

Even beaming through the lid:

Here's a blog post about it on Hackaday, also showing the lower signal amplitude compared to regular CD.
For me, so far it worked in 2 out of 4 CD players/drives. And I didn't even try with those that can't read CD-RW, as those can probably be crossed off right away.

Anyway, what happens when it's upside-down? Obviously, "doesn't work" is the answer. But at least we can see the lens dance a bit, trying to read the disc:

If you're worried about data consumption, this video is less than 300KB in size thanks to AV1. ^Although^ ^it^ ^took^ ^7^ ^minutes^ ^to^ ^encode...^

And something funny to add.
I ripped it once, there was weird noise, so I tried it again. I played random track, "David", and skipped through it. It sounded corrupted. So I tried playing it directly using VLC. Still the same. Thinking it was the drive, I tried my Discman. Same issue.
Is the disc bad?
But, after finally getting the track from the internet, I found it just sounds like that.

I think someone screwed up on "3 business days to pick up".

Software often has pretty good documentation. But real-world things don't.
And if I don't know exact steps to do something and what to expect, I just can't really push myself to try it the first time. That can be put into an interesting sentence.
"I can't do it because I haven't done it."

Recent example:
I want to take a bus. But I haven't yet used the company that operates these buses. I do have an RFID card with e-wallet that is compatible with this company. That is because they operate as intercity transport in the same region, and same tickets are valid there. Except for one line, the one I am most interested in.
Now comes the problem.
How am I supposed to board? How do I buy the ticket? On other lines, am I supposed to prove I have one?

Before I start with the issues of unknowns, I should mention I so far spent 3 hours trying to find the information. That includes searching for videos which may show what others do in the background. In one similar case I found the answer from a TV news report filmed near a bus stop, and my answer was in the background.

So, boarding. Is it front doors only, or do the doors not matter? I've seen both.
Purchasing the ticket: There was a mention of possible cash payment, buying the ticket "from the driver". I managed to find photos from inside the bus, and to further my confusion, there were 3 terminals. All of them RFID-compatible.
2 are ticket validators next to both doors.
1 is on-board computer (apprears to be TransData Vesna model) along with a ticket printer and RFID terminal, operated by bus driver.
If it was just one of those, I'd know what to do.
I found one video from that special line. The person presented a QR code of valid ticket to the driver before boarding. But I don't use that payment method.
But if it's front doors only, why are there validators in the rear? Or was that just something specific to this line?

Now, I could do the one obvious thing, ask the driver. But I really hate talking to people I don't know.
An alternative I am contemplating is sending an e-mail to the company with my questions. They do have one for customer questions.

This is always a problem if I don't know exact steps for something. And even then I am still really anxious before I actually do it for the fist time.