
Disc rot is a challenge for both archivists and collectors (2017) - anonymfus
https://www.vice.com/en_us/article/mg9pdv/the-hidden-phenomenon-that-could-ruin-your-old-discs
======
propter_hoc
This is such a huge problem for retro gamers. Any games on optical media, even
those that aren't particularly old are at risk. As the article mentions, it's
doubly infuriating given how optical media was marketed as more durable than
cartridges. Meanwhile, a bunch of my Dreamcast and PS2 games have disc rot,
while all my carts are still 100% playable.

Besides disc rot, optical drives are also at high risk of the laser dying -
this has happened to a PS1, PS2 and Dreamcast of mine.

For these reasons, the most serious retro gamers I know are modding their
optical drive systems to replace the CD drive with a SD-card based optical
drive emulator.

Anyway, thank heavens for emulation and the homebrew fan community. Without
them, so much of video game history would be lost.

~~~
Grazester
I have not come across a Dreamcast game with rot. I have some early games
which were just pressed badly and the top player in completely pealing off but
it was not rot. The Saturn Discs on the other hand I have come across more
than a few with rot.

------
bigdubs
The loss of what.cd wasn't difficult because it made piracy hard, it was
because the users had created one of the best fully verified lossless cd audio
archives on the internet.

Much of this content has popped up (or even been extended) on replacement
trackers, but it's only a matter of time before the heroic operators of these
trackers get forced to shut down too.

~~~
Iv
I remember the early days of piracy, Napster, Kaza, eDonkey. People were
simply sharing all their files. There was pride in having a hard to obtain
item, such as TV shows from the 60s, movies not released in DVDs, etc...

P2P could have made archivists jobs so much easier. This is a tech that should
have been the next iteration of internet that we killed for no good reason.
Not even greed, just a refusal to evolve a profitable but obsolete system.

~~~
javajosh
I used to agree totally, but now I have a more nuanced view. While artificial
scarcity offends my hacker sensibility, I also have to admit that this creates
a society I like, with talented wealthy celebrities, and a large population of
people who make their living in and around the industry. I'm not sure I would
like a society where creative acts only happens in home studios and the work
is given away for free, and all artists have to have day jobs.

~~~
Iv
I never said the new model was "give away everything for free" I just said
that "Consider every copy needs to be paid even though making a copy is
basically free of cost and that this forces us to put a terrible censorship
mechanism into place" was not the right approach.

Now that there are crowdfunding campaigns and tons of tools for
microtransaction, that is even less excusable than when you had the effort to
imagine the apparition of these obvious solutions.

~~~
hakfoo
I feel like we're screwed until we get over the "ownership" model.

It means we spend more effort on metadata (What are we allowed to do with it?
Who owns it?) than the actual data.

It has stood directly in the way of new creative types (sampling in music, for
example) and locked away content where the metadata is faulty/lost (orphan
works problem)

It falls apart badly at scale (if you wanted to get distribution rights for
everything on an OSX/Windows installation image, imagine the number of third
parties alone, plus the original developers, you'd need to sign off)

and then it only really incentivizes work that's commercially appealing, not
necessarily the technical best.

I dream of a day where people who want to create will be able to get a
stipend-- it might cover a modest lifestyle, but ensures they can live the
dream of being an artist/musician/programmer without having to clutch tight
over every scrap of their output to keep their income streams alive. If we did
it through a tax-funded endowment rather than market forces, we could probably
finance a lot more creativity that way (think how many touring singers we
could finance at 50k per year for the price of one Taylor Swift, or how many
programmers we could hire to work om their passion projects in database theory
for what is currently being spent on Oracle licenses.)

------
userbinator
Theoretically, optical media should be easier to recover than magnetic,
because the technology to view their surfaces in detail is readily available
--- a light microscope is enough to humanly view the actual recorded data on a
CD and even a DVD:

[https://3.14.by/en/read/cd-dvd-microscope](https://3.14.by/en/read/cd-dvd-
microscope)

[https://www.youtube.com/watch?v=Y8_HCLPdpkI](https://www.youtube.com/watch?v=Y8_HCLPdpkI)
(CD-R)

It would be interesting to see what "disc rot" looks like at that level of
detail; and if better reading hardware may be able to read it. In particular,
pressed discs actually store data in the varying height of the polycarbonate
disc, so as long as those pits and lands haven't been damaged, even if the
metallisation is gone, the data remains intact; and if there was a way to
strip and re-coat that layer, pressed discs could be recovered. For CD-Rs,
perhaps the dye has faded to the point where the typical drive (which can't
really spin the disc slower than 1x) won't be able to discern the pits from
the lands, but if that data can still be _seen_ somehow, it's recoverable.

~~~
BarsMonster
I am the author of these photos... If you have a sample of rotten disk - you
can send it to me and I'll take a look. Contacts are on the site.

Now my hardware is better, CD and DVD are easy to observe without physical
damage. I also can see data on BD disk, but it is on the border of what is
possible.

I also tried to decode data from the image, but it will require more
collaboration.

------
Erlich_Bachman
For archivers there is now writable M-Disc bluray discs which claim to have
longevity of 1000 years. It might be an overexaggeration, but they do use a
different technology to record the information, a non-organic layer which is
chemically much less active and will inevitably decay slower than a regular
CD/DVD. There have even been some accelerated aging tests that were able to
somewhat confirm that. If you're into archiving you might want to look that
up.

~~~
copperx
After looking that up I've decided it's far cheaper to upload my data to S3
with maximum data center redundancy, fund my AWS account with a big enough
balance to be able to pay for a decade of service, and give my keys to people
I trust.

~~~
vbezhenar
You should not put all eggs into one basket. Amazon might ban your account any
day and you'll end up with no data. Or your data might lost because of some
bug. There's Google coldline, there's online.net C13, they have similar price.
Use at least 2 different providers.

~~~
masklinn
Backblaze B2 as well, they advertise B2 at 0.5c/GB/mo, coldline is advertised
at 0.4 (though the official docs quote 0.7c[0]), Glacier is 0.4 to 0.5
depending on the zone.

Azure apparently has an "archive" tier for 0.1c, which you can lower even
further with long-term high-volume reservation: if you reserve 1PB for 3 years
it's 0.081c/GB/mo (using only local redundancy) in the cheapest DCs where it's
available (some DCs either don't have that feature at all, or it's way more
expensive e.g. 0.1636 in asian DCs where it's available).

[0] [https://cloud.google.com/storage/pricing#storage-
pricing](https://cloud.google.com/storage/pricing#storage-pricing)

------
fzeroracer
This is going to be one of the reasons why CD collecting (whether it's games,
music or otherwise) will likely stall. Even games which have been kept in
perfect condition can suffer from rot as a result of poor quality control.

Cartridges are generally more hardened unless they contain some battery-based
saving system and even then a dead battery can be replaced.

------
jiofih
I considered all my old CDs dead (music and PC games - RIP Phantasmagoria,
plus MP3 collections) over a decade ago.

The majority of them developed white spots or detachment of the disc layer.
This has been known since the early 2000s, I’m surprised anyone would collect
them without being aware of the risks.

------
sowbug
Has anyone looked into whether M Disc is less susceptible to the problems
mentioned in TFA?

~~~
masklinn
They claim to, but it's hard to determine that, and whether other archival-
targeted discs (or which there are several e.g. Northern Star DataTresorDisc,
MPO Gold, Verbatim Archival) are also resistant to disc rot, because it's
unclear whether accelerated aging triggers disc rot in general or only some
very specific instances thereof.

(apparently defunct) syylex's GMD would most likely be structurally immune to
disc rot, but you had / have to really really want to make your data rotproof:
single-disc (4.7GB) order was 160€ (>$200 at the time). Not including VAT/GST.

------
hadlock
I have the original install disks for BoeingCalc, the precusor to the more
famous VisiCalc (Excel) but they're unreadable using consumer grade tech.
Probably the only public copy of the software that I'm aware of.

~~~
acqq
> BoeingCalc, the _precusor_ to the more famous _VisiCalc_

No way:

[https://en.wikipedia.org/wiki/VisiCalc](https://en.wikipedia.org/wiki/VisiCalc)

VisiCalc: Initial release 1979

[https://en.wikipedia.org/wiki/SuperCalc](https://en.wikipedia.org/wiki/SuperCalc)

SuperCalc: Initial release 1980

[https://en.wikipedia.org/wiki/Multiplan](https://en.wikipedia.org/wiki/Multiplan)

Multiplan: Initial release 1982

[https://en.wikipedia.org/wiki/Lotus_1-2-3](https://en.wikipedia.org/wiki/Lotus_1-2-3)

Lotus 1 2 3: Initial release 1983

[https://en.wikipedia.org/wiki/Boeing_Calc](https://en.wikipedia.org/wiki/Boeing_Calc)

Boeing Calc: Initial release 1985 (6 years _after_ VisiCalc).

As it was released, it could read "standard" VisiCalc and Lotus 1-2-3
documents, according to Computerworld:

[https://books.google.at/books?id=97eagSKygYsC&pg=PA48&redir_...](https://books.google.at/books?id=97eagSKygYsC&pg=PA48&redir_esc=y)

What's interesting about Boeing Calc is that it allowed storage of its
documents "online". But it was surely only for specific local setup, so it was
probably "on the local server."

~~~
hadlock
Ah, I think what I was remembering was that you could have multiple
worksheets/"tabs" and run calcs between them, like modern excel. I don't think
visicalc supported that level of complexity until later.

------
pmarreck
What prevents, or tries to prevent, bit rot in standard CPU hard drives/flash
drives? Is there some built-in forward error correction at some layer? If not,
how could one add some?

~~~
vbezhenar
Yes, all modern disks use error correcting. Wrong bit reads happen frequently
in HDD and corrected all the time. Bits can't rot in HDD or SSD outside of
firmware bugs or transmission errors. You'll get sector read error instead of
wrong data.

~~~
huhtenberg
> _Bits can 't rot in HDD or SSD outside of firmware bugs or transmission
> errors_

The entire photography community begs to differ.

Gradual degradation of stored image data across HDDs of all vendors is very
well documented, mainly because the bit rot is _very_ easy to spot when
working with visual data.

Bit flips are persistent and they occur on the media itself, not in
transmission. There are plenty of theories, including one that argues that
bits are flipped by stray neutrinos, but nobody knows for sure.

~~~
masklinn
> The entire photography community begs to differ.

Also ZFS. Part of its purpose and design goals was countering bit rot (as well
as device hostility to keeping data safe), as Sun had customers affected (even
with ECC). Hence the end-to-end checksumming amongst other features.

scrub exists pretty much just for bit rot: you run scrub regularly, it goes
over the disk, checks that every block checksums properly, and if they
don't[0] it repairs the data using the non-corrupted copy (assuming you have
one).

[0] and your dataset is replicated, note that even if you don't use a raid
configuration you can mark important dataset as to-duplicate for this purpose
(this is _not_ equivalent to device redundancy, it's a feature which exists
solely for bitrot / corruption protection)

------
ohiovr
I was tasked with transfering a large collection of cd-r media to hard disk.
About 10% was unreadable or corrupted. I have not had a shelved hd go bad yet.
I had an amiga 3000 from 92 boot after 25 years of inactivity. Also booted up
a classic 8088 that was stored in a basement for about 30 years. No problems
with either. Looks like a shelved hd is a cheap and reliable archival option.
On a long enough timeline I would expect all cd-r media to be unreadable.

------
pmoriarty
For DVDs and CDs, error correction can be added using dvdisaster:

[http://dvdisaster.net/](http://dvdisaster.net/)

~~~
tzs
That link does not work, because there is no "A" record in DNS for
dvdisaster.net. Here's the latest snapshot in archive.org [1].

It also seems to be available on Sourceforge [2], but that seems to be about 5
years behind what was on the now non-existent dvdisaster.net website.

[1]
[https://web.archive.org/web/20180428070843/http://dvdisaster...](https://web.archive.org/web/20180428070843/http://dvdisaster.net/en/index.html)

[2]
[https://sourceforge.net/projects/dvdisaster/](https://sourceforge.net/projects/dvdisaster/)

------
rasz
Afaik pressed disk rot is reversible, data is stored on the plastic part (as
the name suggests its pressed in by the die), repair would involve sputtering
new reflective surface. Plastic itself will probably hold tens of thousands of
years. Writable disks are another matter altogether.

------
madengr
Makes me wonder if there is some probability of error vs information density,
irrespective of media. I assume eventually you’ll hit some quantum limit where
so much of the data, is error correction that it’s not worthwhile. Maybe
instead of going denser, it just needs to go larger.

------
james-skemp
I've got a pretty significant collection of PlayStation 1 and 2 games, and
every time I see an article on disc rot I look to see when I need to be
worried.

Has anyone seen a list of when disc-based systems might start showing signs?
Something like game consoles and capacitors.

~~~
stevenwoo
Not exactly what you are asking but I recently sold off my physical CD
collection of about 500, after being in my closet for the past 20 years so no
temperature/climate extremes, a few of them had signficant value on EBay, but
when I tried to use Exact Audio Copy to verify they still could be read, about
half no longer matched the online checksums or the original CD rip I had done
before putting them in storage. There were three from Denon Japan that had
physically deteriorated inside the disk, I could see there was a problem from
a visual inspection.

~~~
rixrax
Aha! This must be why them audiophiles prefer to listen to their music using
$$$ cd transport from original media! You can hear the difference!

On a serious note, I’m in a similar boat, we’re in a middle of the move and it
appears that my cd collection is in same predicament. So I’m debating whether
to throw them to trash, or keep around (mostly for cover artwork, and to keep
my Exact Audio Copy -> flac transfers just a bit more legit (I care of such
things)).

~~~
diamondlovesyou
I dislike CD. My equipment is capable of 192khz/32bit (some only 24bit
though), so CD are pretty much trash at 41khz. Better than MP3, solely due to
the info MP3 throws away, but not great.

Tidal goes higher, to 96khz on master quality where available (the vast number
of tracks are _not_ master quality, sadly).

~~~
starsinspace
You might want to read [https://people.xiph.org/~xiphmont/demo/neil-
young.html](https://people.xiph.org/~xiphmont/demo/neil-young.html)

------
nicholast
I think I've heard that exposure to high variance in temperature can
contribute. For example by storing CD's in your car.

------
FpUser
I have whole bunch of CDs and DVDs (media and data) many way older then 10
years. Some I burned myself and some were bought. Nearly all doing nice and
dandy.

More then that I have an old box of 3" floppies dated 92-95. I recently
decided to check some old code, bought USB floppy drive and I was actually
able to read them. Well not all of them but still ...

~~~
ddingus
Thing is they work, until they don't.

Nearly all may = massive decline soon as much as may mean you are done for
another decade...

If you value it, move it now.

~~~
FpUser
Who says that I did not. All that really matters was backed up years ago in a
few places. But I still have the originals and was just curious. There is
something about fishing out old CD and putting it into player.

As for those floppies I was just curious. I could care less if I did not find
that old piece of code I mentioned. I was just curious to look at it and see
how my way of thinking did change.

~~~
ddingus
No worries. That is written for passersby as much as anything else.

