When Sony released the PlayStation, the first
commercially successful game console to use
the compact disc as its storage medium, they
had a problem on their hands.
Using a CD gave them all sorts of advantages,
but the CD burner and CD-R presented a challenge.
What’s to stop someone from making illegal
copies of our precious intellectual property?
Well, they thought of a solution.
If I take this copy of Parappa the Rapper
and pop it in my computer’s CD drive, it
can see what’s on there.
And it will gladly make a copy.
My duplicate disc has exactly the same files
on here.
Awesome!
It should work!
And yet, it doesn't.
The PlayStation knows that this is a counterfeit
disc, and it won’t play it.
Why?
Well, the data on these two discs may be exactly
the same, but this disc is missing something
which cannot be replicated by a CD burner.
Now, it’s actually pretty easy to get around
this.
Mod chips and disc swapping were two well
known ways to bypass this copy protection.
And of course these days, there are emulators,
so using the console itself isn’t even required.
Now I’m not going make a comment on the
pitfalls of DRM or the people who circumvent it.
Sony has valid reasons for using it, and there
are also perfectly legitimate reasons for
an individual to use a copied disc--for example
to provide a backup of your software library.
But in this video, I’d like to suggest a
way that Sony could have made the PlayStation
discs almost impossible to copy.
There’s a certain quirk in the design of
these consoles that suggests they might have
had this in mind, but abandoned it.
So first, let’s take a quick look at the
history of the console, as well as how the
copy protection actually works.
The original Sony PlayStation was a groundbreaking
product in a number of ways.
Though not the first video game console to
use the compact disc for data storage, it
was the first to achieve widespread success.
There’s a fascinating history as well as
a juicy tale of corporate backstabbing behind
the PlayStation’s creation which I won’t
go into here in much detail.
But if you weren’t aware, the PlayStation
started as an accessory for the SNES.
Yep, Nintendo hired Sony as a hardware accessory
partner, and after deciding that the terms
of the contract weren’t to their liking
in regards to software rights, Nintendo just
shoved Sony aside and instead announced a
new partnership with Philips.
Rather than just abandon their work, Sony
decided to make their own game console as
the ultimate F.U. to Nintendo.
Using optical storage for game data had tons
of advantages over the then standard ROM cartridges.
They were cheaper to make, could hold MUCH
more data, were smaller, more versatile, and
due to that extra data, allowed for things
such as CD-quality audio alongside gameplay.
The CD-ROM’s biggest disadvantage was that
of a slow load time, as the data being read
from the disc isn’t coming in particularly
quickly.
A ROM cartridge could be read at any point
randomly and with higher data throughput,
allowing many games to load nearly instantly.
Oh, and the CD was also pretty fragile, so
there’s that, too.
And, uh, early consoles suffered from a poorly
designed CD reader, so…
well they weren’t perfect.
Even though the original PlayStation only
has a measly 2 megabytes of RAM, a normal
CD only outputs 1.2 megabits per second.
The CD-ROM drive in the PlayStation could
operate at 2X speed, but even then it would
take 6.5 seconds to fill the RAM completely.
But of course, it usually took longer than
that, as the laser would have to dart around
the disc to get all of the data it needed
to load the next environment.
Want to play a skirmish in Twisted Metal 4?
You’ll be staring at this screen and listening
to this for a good while.
[Sound of console seeking data on CD]
Anyway, though there were downsides, the CD-ROM
is arguably what made the original PlayStation
so successful.
But it also introduced that unique problem for
Sony.
All cartridge based video game systems are
essentially immune to counterfeit copies being
made of their games.
You’d need to have awfully specialized equipment
to duplicate one of these, and then you’d
need to track down a blank cartridge with
writable memory.
So, it was pretty much never done.
But the CD-ROM, well that’s easy as pie
to copy!
Although they were pretty expensive at the
time, the CD Burner was very much a thing
when the PS1 was released, and so was the
CD-R. Obviously worried about the potential
for piracy, Sony engineered a pretty clever
trick into the system to ensure only legit
discs could be played.
However, it wasn’t actually that clever.
OK, well, the actual feature is, but the implementation
wasn’t.
Like I said before, in reality it was pretty
easy to get around the copy protection.
So then, how does the copy protection on the
PS1 discs work?
First, let’s get it out of the way and say
that the black color of the disc has nothing
to do with it, whatsoever.
Though one promo video about the PlayStation
suggests that this could be the purpose, it isn’t.
This is just for looks.
[NARRATOR: Black ink is added to the plastic
to give the CD its distinctive, “cool PlayStation-only look.”
This also helps protect the CD from illegal
copying.]
Actually, it’s not even black, it’s a
very deep purpley-blue.
This is a similar color of plastic to what's
commonly found in front of infrared light
sensors on a device with a remote control.
It’s completely transparent to infrared
light, but mostly opaque to visible light.
There was nothing special about the PlayStation’s
CD-ROM drive that allowed it to read these discs.
The infrared light of a normal CD laser will
read it just fine.
Side note--In my last video, I made an error
in suggesting that DVD players don’t have
an infrared laser, and use their red laser
to read a CD.
This is not true, in fact many early DVD players
have two complete laser pickups on a single
sled, and later devices used the same laser
with two diodes.
The wavelength of light is pretty important
for reading an optical disc correctly--it’s
tuned to the size of the pits--so a second
infrared laser diode is necessary to read
a CD.
I had completely forgotten about the importance
of wavelength, and thankfully the comments
set me straight.
One commenter noted that CD compatible DVD
laser pickups usually have two adjustment
pots on them, one for the IR laser, and one
for the red laser, and sure enough,
there they are!
Anyway,
What Sony actually did was to add two things
to the disc during mastering that weren’t
normally there on a garden variety compact
disc.
Well, actually, it was one addition that accomplished
two tasks.
To understand what they did requires a little
bit of knowledge into the laser pickup system
of any optical disc format.
It’s impossible to produce a CD, DVD, Laserdisc,
Blu-Ray, or economic policy that is exactly perfect.
There will always be some imperfections.
The discs aren’t usually completely flat,
so the distance between the disc and laser
lens is constantly fluctuating.
The disc is also never exactly centered, so
the pits usually move back and forth with
each rotation.
To handle this, the objective lens is sort
of floating, and electromagnets can lift it
(or lower it) as well as wiggle it left and
right it to make sure the pits are in focus,
and that it’s following the data spiral.
To see this in action, it’s actually easiest
to look at a Laserdisc.
This disc is badly warped, and towards the
edges the laser is bouncing pretty wildly
to keep its focus distance constant.
Though almost never this extreme, a CD player
or PlayStation needs to do this, too.
In fact, here’s the laser of a PlayStation
wiggling back and forth ever so slightly to
read the data from this Audio CD.
This clip also shows how the laser carriage
only moves for coarse tracking in steps.
Notice how it moves outward, but the position
of the lense relative to the disc doesn’t change.
Now, the laser’s movement is only there
to maintain tracking on the data stream.
A CD player couldn’t care less about what
the Laser is doing,
it just wants to see the data.
Any wobbliness of the track is irrelevant
to its goal of reading the data; so as long
as the wobble isn’t too extreme, its presence
is of no consequence.
Generally, the circuitry in charge of this
tracking and focus is part of the laser pickup assembly.
This task is done at the hardware level, and
can be considered automatic from the perspective
of the circuitry that actually processes the
data itself.
There’s a really great paper linked in the
description that goes over how this is actually
accomplished.
What Sony did was introduce a way to actually
keep track of how the laser lens moved.
The hardware would monitor the horizontal
movement of the objective lens, and it was
looking for a specific wobble in the data
it’s reading.
As part of the mastering process in PlayStation
discs, the very first sectors of data in the
pregap are recorded with a wobble of a specific
frequency.
Rather than a smooth spiral, the track looked
something like this.
The wobbling was also used for encoding which
region the disc was for.
The region code was amplitude modulated into
the wobble itself, and if the code on the
disc didn’t match the console’s BIOS,
it would not play.
The reason this worked was that any ordinary
CD drive would just ignore this wobble.
Actually, ignore isn’t quite the right word.
It was unaware of the wobble.
The tracking circuitry in its laser pickup
would just do its job and keep the laser in
line with the data stream.
It didn’t matter how the data wobbled, or
even if the data wobbled.
Its job was just to get the data.
When you made a copy, that copy would be missing
the wobble.
When the CD drive is reading the disc to make
an image file for burning, it isn’t even
aware of the wobble.
The data captured during the disc read is
all that matters for burning the disc.
Now, a CD burner is looking for a wobble
on a CD-R, but for a very different reason.
A CD-R has a premade wobble molded into the
polycarbonate--that’s the plastic the disc
is made of.
This wobble contains the ATIP, which tells
the CD burner the properties of the disc such
as its capacity and maximum write speed, and
throughout the rest of the disc it wobbles
at a constant frequency.
A CD burner is looking for this wobble as
it writes to a disc both to maintain proper
tracking as it writes on it, as well as to
maintain the proper writing speed.
Because this wobble is already there on a
CD-R, even if a CD drive could detect the
region-encoding wobble on a PlayStation disc,
it couldn’t recreate it.
To recreate the wobble of a PlayStation disc
would require jumping in and out of this premade
groove, which the burner can’t do.
Even if it tried, by crossing the premade
lines, the data would likely be impossible
to read correctly.
Where Sony failed was by being a little lazy
with how disc authenticity is checked.
With few exceptions, the console only looks
for this wobble at bootup.
People figured this out, and by defeating
the lid switch and carefully watching a disc
spin, you can see when it’s checking for
the wobble and swap in a burned copy for a
real disc with a little practice.
The reason this worked is that Sony built
in a healthy bit of tolerance for damaged
discs; so as long as you are fast enough,
it will just pass the disc off as being scratched,
thus needing multiple attempts to read the
data.
But disc swapping was annoying and also could
damage your discs and perhaps even the console,
so the other option was to install a modchip
that would inject the code into the system
at the right time, so even though the laser
wasn’t seeing the wobble, the processor
would think that it did.
Game developers eventually created ways to
detect a modchip, so this wasn’t completely
infallible, but it was still a relatively
easy way to play a burnt disc.
So now that you know what the PS1 does to
determine the validity of a disc, as well
as why it was so easy to get around it, here’s
where my little theory comes into play.
I had mentioned there’s a design quirk.
When you open up the lid of a PS1, you might
notice that the area that holds the CD is
MUCH larger than the CD itself.
Could it be that Sony had originally intended
for PS1 discs to be larger than a standard CD?
Some people think the PS1 discs contain data
outside the range of a normal CD’s laser
carriage, and that this is how the copy protection
works.
While this isn’t the case, Sony could have
done that.
And if they did it by going outside the normal
readable area, they could have really locked
this down.
Imagine that the PlayStation discs were an
extra 3 centimeters across, making it a 15
centimeter disc rather than 12.
If Sony had extended the rails on their CD
drive in here, the laser could read all the
way to the edge of this slightly larger disc.
Not only would this have increased the amount
of data on the disc, but it would have made
copying them almost impossible.
Almost every CD drive has a second insert
for 8 cm discs, and top loading drives can
of course handle them, too.
The physical size of a CD can be smaller,
and it will still work.
But if Sony had gone bigger, you could not
physically fit a PlayStation disc into the
standard five and a quarter inch CD burner
in your PC.
If would fit fine in here, but there’s no
way it will make it in here.
If they had done this, the PS1 could still
play audio CDs just fine.
It wouldn’t remove any functionality from
the system.
It’s already more than capable of playing
an 8 cm CD OK.
And if they had always ensured that some of
the game data was written outside the 12cm
diameter of a normal CD, even on smaller games
which needed less than the 700 megabytes of
data available on standard CD, a copy would
be impossible to make without the console noticing.
If Sony had gone this route, can you imagine
how difficult it would be to make a duplicate disc?
No one was making CD drives capable of reading
a disc that large, and there would be little
incentive to start doing so.
Even if a CD burner appeared on the market
which could handle a 15 centimeter disc, how
easy do you think it would be to get your
hands on a 15 centimeter CD-R?
Now, it’s obvious why Sony didn’t do this.
The whole point of using the CD was to make
manufacturing games quick and cheap.
To make a 15cm CD is really to make an entirely
new format.
That would require new disc pressing machinery,
or at the very least significant retooling
of existing machinery.
Also, a new case design would be needed, with
a physically larger disc being more difficult
to store.
The standard CD jewel case already had the
support of countless storage systems.
But if they had decided to just make the discs
a tiny bit bigger, which the design of the
early consoles suggests was possible, if not
intended, mod chips and disc swapping couldn’t
have done a thing.
A burned PlayStation game simply couldn’t
exist.
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[Snaps fingers] And That!... is the end.
