CDs: More to Talk About (Sony vs. Philips)

CDs: More to Talk About (Sony vs. Philips)


[ The comments being read snarkily ] …the rest of that comment was really insightful, thanks for sharing. OK, could I have been a little more clear? “I’ll show you Sony’s system later on,
but if you…” Yes. Yes I could have. But, this is in fact “later on”, so perhaps
maybe we shouldn’t jump to conclusions so quickly. Tell you what, I’ll work on being a little
more precise in my choice of words. And perhaps you, dear viewer, could refrain
from jumping to conclusions quite so quickly. If we put our minds to it, together, we can
enhance our understanding through complex thought both on the part of the speaker, and
on the part of the listener. ♫ And that’s how the world gets better ♫ Alright, this video is coming at you in three
parts. As we discussed in the last video– NO WAIT,
wait wait wait. The ding was way too loud, let’s tone it
down. [ Ding sound from Jeopardy! ] Much better. So as we discussed in the last video, we’re
gonna take a look at some of the waveforms coming from the components of this Magnavox
(which is really a rebadged Philips because Philips couldn’t use that name in the US
due to it’s passing similarity to Philco, I guess, but that’s a stretch) CD player. That will be part one. In part 2, we’ll take a look at a Sony laser
pickup and discuss the differences. Plus I will tear this one apart to expose
the laser diode and photodiodes. And in Part 3, we’ll discuss why Sony’s
pickup solution would become the default standard, used to this day in optical drives. We’ll begin with Part 1. And Part 1 will be quite a bit different from
most other videos. That’s because much of it is unscripted. Off the cuff. Just gonna wing it. Yeah. But first, a few corrections. As usual, the Internet has provided answers
that I did not find, and has revealed some mistakes and false assumption from the last
video. Of course. But that’s OK, we all make mistakes, and
now I’m gonna tell you what we learned thanks to the diligent research of more knowledgeable
people than me. Remember it’s OK to not know everything. And it’s OK to ask for advice from professionals. ♫ And that’s h–♫ Let me reveal the most dumb mistake, and it
was right on screen. The best kind of mistake. I had been assuming that pin 10 was the output
signal from the focus chip, and that it would be a binary stream from the pits and lands. Boy was that wrong on many counts. First, it’s not pin 10 that does that, it’s
pin 3. And it’s labeled right here on the datasheet. Pin 3 is also labeled to decoder, which I
missed, and most importantly it’s a sum of the outputs from all 4 photodiodes as illustrated
right here. Yes pin 10 also gets the sum of the 4 diodes,
but unlike pin 10, pin three has an amplifier, equalizer, and another amplifier to boost
the output. Hm hmmm. I want to give a big thanks and shoutout to
Zim0256 who not only created the helpful diagram that I used on a few occasions but who also
gave more complete info on what is going on. The Motorola processor is a custom chip based
around an HC08 microcontroller, and it is in fact the decoder that is doing most of
the work. I couldn’t find its datasheet because the
P on the end was limiting my search results. And to think, we just learned about minding
our p’s and q’s. Anyway, in fact the decoder is handling all
the raw data; undoing the eight-to-fourteen modulation, isolating the subcode, and all
that. It even digitizes the output from pin 3, which
at this point is still analog which we’ll see in a moment. It sends the extracted subcode to the processor
so it knows how to handle the disc and respond to user requests. Really, the processor is just managing the
living and breathing tasks of the machine, such as the user interface, display, and other
goodies like popping the disc tray in and out and getting the whole process going. Speaking of the disc tray, a few people had
asked how the machine can tell that the disc tray has been pushed in manually as opposed
to someone hitting the open/close button. Some other people noticed this strange button
switch near the decoder. These two groups of people are discussing
the same thing. To the right of the disc tray is a little
series of levers that rest on top of this button when it’s assembled. Little nubs on the bottom of the tray will
cause this to push down on the button in either the open or closed position. This not only tells the processor that the
tray has reached the end of its travel in either direction, but it also means that it
can detect if the tray has been pushed in, as the button will be released (and thus the
switch opened) as soon as the tray is moved out of its open position. OK, it’s time for the script to be put to
the side. I’ve got a sort of odd setup here, because
I need to see both the oscilloscope screen and what I’m poking on the board, so we’re
gonna do some picture-in-picture editing magic and throw the scope screen up high. Excellent! And you know what, maybe we’ll throw another
camera up here so you can see what I’m doing. Even better. All the cameras! All the tripods! Well this is… awkward. It’ll have to do. As promised, we’re gonna poke around on
some of the things here! Now I brought my laptop here so I can actually
go and look and see what I’m looking at, and you’ll notice these, uh, wires that
I’ve soldered onto chips underneath. I’ll bring up the image of that. Part of the issue with this player is that
it has to be–the ribbon cable between the drive and the board is very very short, and
there’s pretty much no way to operate this unless it’s assembled. I really don’t know how people would service
these things, ‘cause it, ya know… a lot of the… a lot of the stuff that I wanna
see is underneath the CD reader like the, uh, the tracking and focus chips are basically
directly under here. That’s not helpful. But we can see what else we can take a look
at. I did find, just from poking–at one point
I found the raw datastream. I think it was one of these guys. Unfortun… what is happening here? Oh. Well this is kind of interesting, what’s…
uh I wonder what’s on this line, let’s see if I can figure it out. Notice that we’re on a really long time
scale. I think this is the subcode. If I can hopefully… get the… trigger… I’m…eurgh… I’m really…have no experience with a scope. So, just. Just so ya know. Let’s try… Oops that’s what I meant. That’s what I meant! The other way… Oh! It’s probably you, OK. Yep, OK. Ha ha! I found it! So this here is the waveform that’s coming
from the amplifier chip from the au, from uh the TDA8808T augh that one, that one. So this, this is the amplified output of the…
oops, of the pits and lands. So this is the raw analog signal coming from
the disc. And if we look a little closer… you can
see if I touch the disc… see how that’s… Oh. Well I’ve killed it. Great. Great job! So if I kinda just touch it you can see the–it
slows down a bit. Let me zoom out a bit. Oop–zoom out a bit. See that? It just completely–it gave up there. That click sound you heard I believe is the
laser kicking up all the way. But yeah so this–this isn’t the raw output
from the photodiodes but this is the amplified output coming from pin 3, going to the decoder. The output from the photodiodes is very very
small, this is… if we take a look and compare the voltage level there’s almost nothing
there. And it’s so noisy I can’t see anything. These all should be the same. There’s nothing there. Which is a shame because I really wanted to
show you that! Oh well. Wanted to show you some interesting stuff,
and I think that we saw some interesting things but not as many as I was hoping. Well, with that disappointing segment out
of the way, let’s move on to the part that I didn’t forget about. To see how Sony handled the optical system
differently, we need to get our hands on a Sony CD player, hopefully of similar vintage
to this Philips one. Oh perfect, a Sony CD changer from 1992! Now it doesn’t really matter that it’s
a changer, there’s still a standard CD mechanism in here, it’s just on a pivot and will happily
pop up and fall down to greet or say farewell to the disc it plays. It works in tandem with the disc tray, which
rather than just being an inny-outty operation, it’s an inny-outty with rotational flair. Now I embarked on the frightening task of
getting this mechanism out of this player. Armed only with an ordinary screwdriver, I
went hamfisted and started unscrewing stuff, before I realized I hadn’t filmed the close
up segments of the laser tracking a disc. After undoing what I had begun, I began once
more. The screws are the enemy! Be gone! Or, be twisted counterclockwise sufficiently
until such time that they can be gone! Having gained unrestricted access to our prize,
I loosened the four screws holding it in place. But it wouldn’t budge. Yet more screws needed liberation, until finally
I had successfully removed the crown jewel from the temple of forbidden technology. And, uh, here it is. One of the big differences you’ll see between
this and the Philips mechanism is everything is much more integrated. In fact this one chip here, if the datasheet
I found is at all correct (link below) has 32 k of RAM built in, does the EFM demodulation
as well as the CIRC error correction, handles the focus, tracking, and spindle motor (using
this chip as a driver to handle the power), extracts the subcode, provides a data output
for the DAC, and can even do such exotic things as double-speed playback and variable pitch
playback (assuming the player it’s inside has those functions enabled). Did I mention it’s bilingual? It’s interesting how just 4 years time managed
to integrate functions that are spread out via multiple chips on this Philips machine
into just this one chip on the board of the laser pickup. But that makes a lot of sense. See, this Philips board only works with
one mechanism. Because its driver components are part of
the main board design, anything but a Philips CDM4 pickup won’t work without at least
some modification. But for the Sony machine, this ribbon cable
is essentially just proving a power, ground, a communication bus to the CPU, and a datastream
for the DAC. This component can be completely redesigned,
and so long as it accepts the same inputs and produce the same outputs, the main board
really won’t care. This allows Sony to make production improvements
and even radical changes to this mechanism and how it works without disturbing the main
board. You can see how Sony played a modular approach
via the markings on the board. This one board was used in many different
players, with different components marked “FOR X player only”. By my count it was used in at least 5 players. Really, Sony’s markings are just a lot more
helpful. Wondering which one of these is the DAC? Hey look, it’s labeled right here. And you’ll find a PULSE chip on the bottom. I’m pretty sure these are 1-bit DACs, based
on some vague research. I’m sure someone will correct me if I’m
wrong, and I’m counting on it. And the fact that they’ve labeled these
jumper connections on the top of the board for what they are sure is helpful. That would’ve been nice, PHILIPS. Anyway, back to the laser because that’s
the real difference. First, gone is the swing-arm. Instead, the laser is mounted on a sled, which
moves linearly with the help of this rack and pinion drive. Now, you might suspect that this drive arrangement
does not have the precision to track the disc. The floating arm of the Philips system means
it can move subtly and precisely to track an off-center disc. But this brutal, inelegant plastic gear train
can’t possibly be used for the tracking. And it isn’t. Just like the Philips system, this lens is
floating and can move up and down. But unlike the philips system, this lens can
also move left and right. With the help of a diode I have laying around,
you can see that the laser can move quite a bit to either side. Let’s take off this plastic shroud to get
a better look. Ah this one is perfect for showing this. Yes. OK, I’m sure you can see these rectangular
coils surrounding a vertical structure. These coils will push the lens upward if a
voltage is passed through them. But if you look very carefully, you’ll also
see a pair of circular coils on the outer edges. When a voltage is applied to these, depending
on the polarity it will attract itself to these handy magnets placed on the sides, or
it will push itself away. This causes the lens to pivot either left
or right, depending on which way you slice it. The best part of this setup is that the lens
is completely independent of the sled that it’s riding on. If the sled moves a bit, it doesn’t care–it
will just react to that movement as though the track of pits it’s… tracking has moved
slightly. That means that the sled only has to move
in coarse steps, and the lens will take care of the rest. But that’s just one significant difference. The other is in the photodiode arrangement. You may have seen the term THREE-BEAM LASER
TRACKING before. Or something like that. In these systems, rather than using only four
photodiodes like in the Philips system, we use six. In the middle are four cells arranged… actually
exactly like the Philips system. These are used in an identical fashion for
focus–an elliptical reflection indicates an out-of-focus beam, and its orientation
indicates if focus is near or far. But to correct tracking errors, two additional
diodes to either side are monitoring for an off-center beam. In these systems, a diffraction grating splits
the laser beam into three. In reality it splits it into infinite beams
of increasingly weak intensity as they deviate from the center but we only care about the
center beam and the two immediately surrounding it. Now, when tracked correctly, the outside beams
shouldn’t land on the stream of pits. They should instead land just outside of them,
which will thus cause them to reflect the featureless boundaries. The reason this works to track the stream
is that if the track deviates, suddenly one of the tracking diodes will start seeing the
datastream. That’s not supposed to happen, so the player
will react by nudging the lens in the direction of the activated tracking diode. This system is certainly more complex on the
hardware side, but given how simple the trigger is–no need to compare ratios, simply see
if a single thing is happening–it’s probably a lot easier to implement. However, this make me wonder if this system
is fundamentally worse at tracking discs. See, I’ve heard anecdotal evidence that
the original Philips single-beam tracking is superior at tracking scratched or damaged
discs. And with the knowledge of how the three-beam
tracking works, that kind of makes sense. Imagine a scratch appears just next to the
datastream. If that scratch is bad enough, it might bend
one of the tracking beams towards the raw datastream, causing the lens to deflect for
a defect that isn’t really there. With the Philips system, it wouldn’t see
this scratch because it only has the one scanning beam. It would ignore it and thus be unaffected. Now of course, these conventional systems
aren’t remarkably inferior. They can tolerate scratches pretty well, too. But it makes me wonder if there is truth to
the anecdote that the swing-arm servo, Philips single beam tracking whatever is indeed superior. One last thing before we answer why this became
the standard. I’m not afraid to tear this apart and find
what inside. So first, you can see the actual laser diode
here as opposed to the Philips machine where its housed in this plastic. This, like in the Philips setup, projects
the light sideways where it hits a prism, get shot up at the disc surface (which the
floating lens helps to keep tracked and focused) and it gets reflected back, goes straight
through the prism, and lands on this little chip here. Now this is interesting, because on this machine
we can actually see the backside of the photodiode array, unlike on the Philips machine where
we could only see the board. If I keep going to remove the lens and get
everything apart, you can see the prism in here. Take a look, it does a great job of reflecting
light at a 90 degree angle. And now, let’s see what we can see of the
photodiodes. Well, don’t get your hopes up–they are
pretty much microscopic. To be fair, we are dealing with laser light
focused on microscopic pits, so its stands to reason that these are probably pretty
small. I don’t have a microscope handy –yet– but I do have my ridiculous macro lens setup so I could get these extreme closeups. You can definitely see that these are three
clusters, with one used for data capture and focus control, and the two to either side
for tracking. To show how small this is, I’ve placed a
dime next to it for scale. For a more International perspective, how
about a micro SD card? And just for fun, here’s the point of a
safety pin. These really are tiny. So now, why did Sony’s floating lens and
stepping platform become the de facto method of reading optical discs? With more photodiodes and greater mechanical
complexity, you might think it to be inefficient. Well it may be inefficient in some ways, but
in most ways it’s in fact much more efficient. First, let’s take size. If we look at the Philips system, you’ll
notice that the entire laser pickup is essentially behind the disc. The pivot point for the swing arm has to be
farther to the rear of the player, otherwise it would simply rotate around the circumference
of the disc, and that wouldn’t be very helpful. This off the bat limited its potential to
miniaturize. And boy, did this get smaller quickly. Portable CD players burst on the scene in
1984. And they would only continue to get smaller,
with one CD player featured by Techmoan actually being smaller than a CD. And that was in 1988, the same year as this
Philips machine was made! In fact, this very mechanism is larger than
it needs to be. If these parts were shifted downward, it could
be no longer than the distance here. And this laser platform could get smaller. And smaller. And smaller. Until eventually you’re into modern slim
drives for PCs which have the tiniest of lenses and thinnest of assemblies. And the PC market would only continue to make
this Philips system harder to justify. In fact, one fatal flaw of the Philips reader
would make sure it fizzled into obscurity: its mass. Imagine in a portable player, which can be
set in any position, or even moved around while playing, that it had this swinging laser
pickup. It’s so loosey-goosey that it’s doubtful
it will track very well. And its mass also limits how quickly it can
move. When CD-ROM drives appeared, and getting faster
and faster and faster, the laser would have to be able to wiggle itself back and forth
at frequencies in excess of 10 kilohertz. That’s easy if you’re just wiggling at
small piece of plastic back and forth, but a lot harder if you’re wiggling this big
swinging thing. And so, Sony’s three-beam laser tracking
would be miniaturized and improved over the years. Developments in anti-skip functionality meant
that CD walkmen could be tossed around without fear of skipping or glitches, or getting stuck
repeating a bit of the track. That was accomplished simply by reading the
disc at faster than normal speeds, creating an intermediary data buffer between the disc
and the processor. The DAC could have upwards of 40 seconds at
its disposal for the laser to get back on track and resume the datastream. Which, thanks to the timecode, is easy to
piece together if a problem does arise, thus eliminating the effects of skipping. And of course, later on the wavelength of
light would change to red, packing the pits closer together and creating the MUSE high
definition laserdisc. And then later the DVD, an obscure digital
video format you might have heard of. Later we’d say, enough with the red, in
with the blue and we’d be packing upwards of 25 gigabytes onto a slightly different
silver plastic thing, after we briefly reenacted the videotape format wars of the 1980’s. Because why not. But we’re getting ahead of ourselves. There’s lots more to talk about. When we next check in on optical disc technology,
we’ll discuss the Yellow Book, the standard published in 1988 that defines the specifications
of the CD-ROM. Then we’ll talk about some writable disc
technologies like CD-R and CD-RW, and then, if interests persists, we might dig a little
deeper into the DVD and some of the follies of its development. Such as how this logo mysteriously features
a disc for a solid state memory format. Hmm. Thanks for watching, I hope you enjoyed the
video! If you missed the first two videos on the
Compact Disc, you can check them out in the playlist on Digital Sound that will quietly
pop up above me. So serene. As always, a great big thank you to every
who supports this channel on Patreon, especially the fine folks that are scrolling up your
screen. If you’re interested in pledging some support
to the channel to help it grow, please check out my Patreon page. Thanks for your consideration, and I’ll
see you next time! [ everyone’s favorite, gloriously tacky
music plays ] Hey one thing, my most viral video to date
was about how Sony used the tracking servos in a CD player to create the copy protection
scheme in the original Playstation. You might want to check that video out, but
be warned that there are a number of annoying things about the flow of information over
there. It goes into a lot of detail about the PlayStation
and some of its history, and the comments on there (if you dare to look at them) indicate
that many people were… not happy about it. So if you haven’t seen it, check it out,
and apologies in advance. Ha, and another thing! So if you didn’t know, there’s a second
channel – Technology Connections 2 – where I upload weird stuff from time to time. And I just uploaded a video of a couple of
CD players that are very similar but have some unique differences. So if you want to check if out, please feel
free to click the link down below or up above.

100 thoughts on “CDs: More to Talk About (Sony vs. Philips)

  1. "The trademarked SD logo was originally developed for the Super Density Disc, which was the unsuccessful Toshiba entry in the DVD format war. For this reason the D within the logo resembles an optical disc."
    You're welcome 😁

  2. That Sony CDP-C225 was our family's first CD player and it was a fantastic one, at that!

    Absolutely love the channel and videos 🙂

  3. Heya! I’m new to scopes as well, but I know just enough to get myself corrected. I was very annoyed when my lowly 20MHz USB scope/logic analyser (but not both at the same time) thing did not come with ground springs. The hook on your probe will (Or.. should.) pull apart and you’ll be left with a bare tip and a ring, which is where the ground clip attaches to. It helps keep a very low level signal integrated because of attenuation and ground loops and whatnot.

  4. On the integration. Sony loves to roll their own silicon. They would’ve had the facilities in place to bang out one chip they they know they’re going to sell forever, and they can make a ton of money off an initially large, but worthwhile, because it was only one, investment. Going fast to go slow, here.

  5. I'm surprised you did not mention Sony MiniDisc, or did you lol. You have an incredible amount of content and I could have missed it.

  6. I love your content. The screwdriver wielding techy in me completely follows this and is fascinated (although we had to hide the screwdrivers as we would end up with a houseful of dismantled equipment, hacked devices and general technology chaos)

  7. You're so not funny. And please, buy yourself a decent jacket and wear a different shirt from time to time. 😒👌

  8. Stream of pits?
    1) That's no way to talk about Lawrence MA and Everett WA!
    2) I'm going to stop giving you white boys if you don't start taking care of them!!

  9. Hey, just found your channel last week. Been watching a few vids. It's really fun to watch because you're so precise. I kind of imagine you're like this teacher who has so many cool things to show.

  10. Hi, great channel! I have a burning question: how do the tracking and focus mechanisms work during a burning operation? Thank you.

  11. From 0:00 to 0:45 this kind of speech reminds me many excuses I gave to my girlfriend for not doing something for her…. Well, "later" is in the future, so, you can't beat later 🙂

  12. Hey man, I really like your videos… just wanted to say that before I continued to be a sarcastic butt.

    Your a little bitter about people’s remarks aren’t ya.

  13. LOL Damn, that William Little is one hell of a translator! Speaking of which, this video went WAY over my little head! I understood about 10 words! I don't like being this dumb, but, at my age there is no helping me now! I am sure this video was a great help to a lot of people as all his videos are. But, me pea brain could take nothing in. Especially that really strange drawing at the beginning with those funny shaped things on it. What WAS that? It looked like an alien type drawing! Oh, well, back to Fail Army!

  14. The Sony machine also used surface mounted components which are much smaller than the through hole ones used in the Phillips machine

  15. Make a video about audio compression next. I think it's fascinating how taking fourier transforms at relatively infrequent sample intervals can actually use much less data than encoding the original signal.

  16. Hahaha, manufacturers designing for service? Unfortunately the thought that goes into repairability for things like this is often near zero.

  17. You forgot to mention that Sony used the differences in tracking to encode information in PlayStation discs, thus allowing to authenticate the disc (and know the region coding).

  18. Your shirt changing colors blew my mind for a second. I wasn't sure at first that it actually had happened, and I had to back it up and play that again to be sure.

  19. I just discovered that my subtitle contributions are all at the end of the description. Planning to add a bunch more languages soon!

  20. Great idea for a new game; "JUMP…to Conclusions"…..a mat you put on the floor with conclusions, you could JUMP to"..
    The "P" at the end of the IC P#….does that mean it's a plastic-body IC?

  21. The Sony decks were more popular, in part, because you could get the entire laser and deck for 12.95. The Philips, Magnavox (both North American Philips) were like 200 bucks for the laser assembly. So customers could economically get any Sony disc player fixed, but would have to think long and hard if they wanted their NAP fixed…..especially if it was part of a system that had multiple RCA inputs, where you could buy a cheap, separate, Sony player to hook up…

  22. I liked the dismantle and use of the scope. Even if you were fumbling a bit it was interesting and my favorite part of this video.

  23. I love the titles on your channels never really think "that sounds fun", next minute I'm already watching.

    Great work and your vids always bring me happiness

  24. I understand about 3% of the content of your videos, but I keep coming back for more. "Pin 10 the output circuit from the focus chip?" No. C'mon, everybody knows that.

  25. I see at 18:17 that you know the international sign for CD Walkman.…now I need to go on another Citation Needed binge

  26. I repaired camcorders, DVDs, and CDs decades ago. I personally liked the Technics CD mechanism with a linear magnetic sled. It looked like the Sony without any gear drive. It could find a random track and start playing it within a fraction of a second.
    One big issue I saw a lot with the Sony mechanism was a failure of the spindle motor. When you load a CD the spindle spins up to speed and the laser reads the TOC. Sony spun the disc up with what I consider too low a voltage so that when the spindle motor brushes get tarnished, it won't get up to speed fast enough and you get a disc read error when you load a CD. The fix was simple, you just sprayed some silicone lube inside the motor and connected 12V to the disconnected motor very briefly. Technics players never had that problem even though they used the exact same spindle motor, because they used a higher start-up voltage. I can only imagine how many Sony spindle motors were replaced that could have been easily fixed. Engineered obsolescence?

  27. When admitting you made a mistake and explained how being wrong sometimes is ok you reminded me of Mr. Rogers

  28. There's a tity detail in this design that's pretty smart actually.
    The part where the gear actually drives the reader back and forth you can see a cut of sorts in the middle of the rack. The top half of it engages on one side of thegear's teeth, while the bottom half engages on the other (because of a spring). That is put there to greatly reduce baklash (only backlash is from the other parts of the gear train that are "good enough")

  29. This series was very interesting for me. I am a hobbyist electronics engineer and programmer, and find your method of presentation to be ideal to all audiences. You go into just enough detail to give people who want to dive deeper enough information to know where to start looking. Thank you.

  30. The difference? I had a Magnavox CD player with the lens built into the tray and the door would slide open while it was running…hardly missed a beat. Try that with a Sony CD drive.

  31. Hello

    I've been following you for ages

    And he really enjoys your movies

    So I do not have to add to that of yours from my own movies

    But here and there I publish something about audio

    And very much enjoyed the form of serving

    And especially the video I worked for years

    in

    Sony

    Thank you

    This film will teach him very carefully that I really know the subject well

    And thank you very much

  32. Firstly: "…from the uhhh… from uhhh… the tee-aid-aid-aid-ohh-aid-tee-ohh-one-aghhh… that one…" Secondly: "…and if I touch the disk.. see how that's… oh, well, I've killed it… Great. Great job…"

    Mnid Blwon

  33. You are wrong , technology connections, pivot method require active magnetic field, to maintain all the time the laser position, which does less suitable for portatile low power consumption, also more sensitive to external movements, it has nothing to do with its size as you theorized

  34. love the series on digital sound! I think a really interesting next step would be explaining lossless and lossy sound compression. I searched around for a video but can't find anyone that explains it as nicely as you could.

  35. This was my very first CD player back in 1986. I traded a working cobra electronica typewriter for this broken CD player. I managed to get the CD player working. I remember it came with the Rolling Stones some girls album. And the first CD I purchased was Led Zeppelin number four. I paid $30 for the CD back in 1986. Great memories 🙂

  36. Y'all remember when things were actaully held together by screws? Not just glued? Yes that was a thing once…

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