How Old School Floppy Drives Worked
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How Old School Floppy Drives Worked


[INTRO] So, in the last episode we talked about cassette
drives, if you haven’t seen that yet, I suggest you go watch it first since it sets the stage
for Floppy Drives. “Ahh! I love talking about floppy disks! Right, so here’s the thing.
I don’t care if they’re 8 inch, 5 ¼ inch, 3 ½ inch, or any of the 3 inch
Amstrad ones or any of the weird things in between. For all over the world, I love collecting
them, I love feeling them, I love looking at them. Floppy disks are more interesting
than pretty much any other older storage medium to me.” Technically floppy drives had been
in use since 1971 in the business market, usually in the form of these large 8-inch
disks. These things were huge, and you can see where they got the name floppy disk from.
These are probably most well-known from the movie WarGames, which came out in 1983. But
interestingly enough, nobody was using 8-inch disks in 1983. However, that doesn’t necessarily
mean the movie was wrong. It could just be that he was given a 5 year old computer by
his parents, which is not unreasonable I suppose. In fact, the computer I use every day is
5 years old, so there’s nothing wrong with that. Also, according to Futurama we’ll be
using these in the future for video recording. “Let’s just see what you were up to last night. While I was asleep.” But the 5 ¼ inch floppy disk is what most
people will recognize from the home computers of the 1980’s. Much smaller than the 8 inch,
but still works pretty much exactly the same. “So, when I think about floppy disks, what
I really think about are the 5 ¼ inch floppies. When I had the 3 ½
inch floppies, I already had a hard disk and so floppies sort of played a different role
in my computing habits. But when I was using the 5 ¼ jobs, that was really
the only storage media that I had.” So let’s have a look at how these work. First of all,
on the outside you have these “relief notches”. The purpose of this is to minimize any bending
of the disk right around the read area. This is the “index hole”, which was monitored by
a sensor so that the drive would know exactly where the disk was rotation wise, but not
all disk drives made use of this hole. This is the “write protect notch”. A sensor monitored
this notch and if it was found to be open, then the drive knew it was okay to write to
it. If you wanted to protect your data, you could put a sticker or piece of tape over
the notch so the drive would not allow anything to be written or altered on the disk. And
since it was not a good idea to leave this area exposed, a “paper sleeve” was used for
each disk to keep them protected. Let’s take a look inside and see how things work.
The magnetic material is very similar to the material inside of a cassette tape or VHS
video cassette. It just happens to be round and a bit stiffer. So this part of the disk
was used for actual data storage. Now you’ll never be able to actually see the data on
the disk, but if you could, here’s how it would look. Keep in mind that the typical disk had
40 tracks starting at the outer edge for track 1 and all the way to the inner edge for track
40. Inside of the disk drive, a “stepper motor” is used to move the read head back and forth
to access these different tracks. Now some drives had sensors to help it figure out
where the read head was, but some drives did not. So if you ever noticed when you turn on an
Apple II computer, the disk drives always make this knocking sound. So, what’s actually
happening here is that the drive is first powered on, since it has no sensor it has
absolutely no idea where the head is. So, the way to get around that is, they just send
the command to back the head back to track 1 and they send that command 40 times, so
it’s guaranteed to be back at track 1. Once the read head gets to track 1 it can’t go
any further so every subsequent attempt makes a knocking sound. It does work, however, and
does make sure the head always starts out on track 1. Commodore drives are known to
make the same sound when encountering a read error or when formatting a disk.Now let’s
take a little bit closer look at how the data is actually stored on the disk. In order to
help figure out where files are stored on the disk, the computer will divide it up into
sectors. These sectors are defined entirely by software and thus can be very different
from one computer to the next. This is an 8-sector format, typical of the IBM PC. So
if you asked for track 16, sector one you would be reading from this area here. And
if you could see the actual bits of data, they would look kind of like this. Each dot
representing a 1 and the blank area representing a zero. Now, one thing you might notice is
that a sector on track 40 is much smaller than a sector on track 1. And yet, they store
the same amount of data in this format. However, other manufacturers handled this differently.
Commodore, for example, used 21 sectors on the outer tracks, then 19 sectors, then 18,
and then 17 for the inner most tracks. As you can see, this made the sectors similar
in size and made more efficient use of the disk space. Also Commodore had some other
oddities such as using track 18 exclusively for the directory. Also, Commodore
disk formats did not use the last 5 tracks on the disk, due to some quality problems
with early drives. However, it was possible to use all of the tracks with a custom format.
Perhaps now it is a little bit more obvious why computers during the 1980’s of different
manufacturers could not read each others’ formats despite being the same physical media.
So, an Apple, for example, could not read a disk formatted in a Commodore. Some systems,
such as IBM typically used double-sided disks. Now what that means is they used two read
heads, one on top, and one on bottom. So they could store twice as much data on a single
disk, well sort of. You see, on Commodore and Apple drives, you could turn the disk
upside down to use the back side of the disk. There’s only one problem. See how the write-protect
notch lines up over here. Well, when you flip the disk around, the drive will now think
that the disk is write-protected and won’t let you write anything here. The solution
is to make another hole. Now they actually sold products specifically designed to do
this. But I would usually just take another disk and use a razor knife to cut a slot
out. Now you had a write-protect notch for both sides, so you could use the full capacity
of the disk. So let’s talk about the actual drive mechanisms themselves. Now, this is
a typical full height drive that would have been used by an IBM PC or an Apple or even
a Commodore back when they were making the PET. A few years later most everyone had switched
to half-height mechanisms. Now check this out. See how much larger a Commodore disk
drive is compared to an Apple disk drive? Why is that? So, Commodore and Atari took
a very different approach to their disk drive controllers. Let’s take a peak inside this
Commodore 1541. Look at that huge circuit board. Wait, what is that? A 6502 CPU, the
same one used in the computers themselves. And here we have two I/O controllers, exactly
the same ones used in the computers, and 8 kilobytes of ROM, and 2 Kilobytes of RAM.
So, it’s very much its own self-contained computer. Let me demonstrate this. This is
a neat little program that makes your disk drive play music. It accomplishes this by
using the stepper mode for the head and vibrating it back and forth. But the more interesting
part is that you can now unplug the drive from the computer and it will continue to
do its thing all by itself, because the program is executing internally. [FLOPPY DRIVE MUSIC] Now, why did Commodore
put a whole computer inside of their disk drives? Well, my guess is that the probably
did it to reduce cost. Because it was no longer neccessary to put a drive controller inside
the computer. And many of the computer users were happy not even owning a disk drive and
just using a tape drive instead. Basically, with an Atari or Commodore, the computer doesn’t
even really know where the information is coming from. It just sends a request out the
serial port and says “I’m looking for file XYZ.” The drive will check the disk and see
if it can find it. Once it does, it sends the file back to the computer. An Apple does
something very different. It has to send specific commands to the disk drive telling it to move
the head, spin the disk, and all of the decoding of the tracks and sectors are handled by the
computer’s CPU. Now you might think that Commodore drives should be much faster, than say an
Apple or IBM drive because they had their own processor on board. Well, it didn’t work
out that way, and in order to understand why you have to go all of the way back to the
Commodore PET. The PET disk drives were HUGE, but they were decently fast because they used
the IEEE-488 parallel interface. It was a 24-pin connector and had 8 pins for parallel
data transmission. Well, when Commodore came out with the VIC-20 a few years later, they
decided to move to a serial interface where data was transmitted one bit at a time. That
wasn’t necessarily a problem, since they were going to use a hardware shift register, which
would take care of this at the hardware level. However, the hardware was faulty and it was
too close to the time of release, so they just did away with the shift register and
instead just programmed the CPU to address the data line directly, and it was
pretty darn slow. And they didn’t even use the most efficient routine possible. But,
that’s the kind of thing that happens when you push design changes into a product at
the last minute before it launches. Since the VIC-20 only had 5K of RAM, it really didn’t
matter that much. But the C64 came out soon after and had a lot more RAM. But they wanted
to maintain backwards compatibility with the disk drives for the VIC-20 so it ended up
being VERY slow. “I remember my first impression of plugging it in and loading up a couple
of disk games, I was very very underwhelmed by the actual speed of this thing. I mean,
this thing was as slow and in some cases even slower than the C2N datasette. And how could
this be? I had no idea that a disk drive would actually be slower than a turbo load on tape.”
Now, interestingly enough, people eventually figured out how to make some more efficient,
and thus faster software routines for communicating with the disk drive. So cartridges such
as this EPYX FastLoad came to market. All this cartridge does is replace some of the
kernel’s disk drive routines. “This is the EPYX FastLoad cartridge. And this is something
that I would recommend to anyone that wants to use a disk drive on a Commodore 64 with
the original disks. This thing will actually speed up loading times, 4 or 5 times. And
this is very compatible; in fact it works with every single disk I’ve thrown at my 1541.”
Commodore later sort of remedied this with the Commodore 128 and 1571 disk drive. The
combination of these two have very fast disk access, but the problem is it is only fast
when operating in native Commodore 128 mode. But since most games were required to run
in C64 emulation mode, the drive was just as slow thus still requiring a fast-load cartridge.
Now eventually we moved forward to the 3.5 inch floppy drives, and sometimes they were
mistakenly called hard disks by people that really didn’t know anything about computers.
Some of the first computers to use these were the Amiga, the Macintosh, and Atari ST. Now, these
guys were with us from the late 80’s all the way into the 2000’s and apparently will even
be used in the future to store robots’ brains. “I downloaded his brain. Everything that is
Bender is right here: His mind, his memories.” It’s basically the same technology just in
a smaller, more durable casing, with a write protect tab that can be moved on or off so
you don’t have to use a piece of tape. So many of you may have heard that the US military
still uses old floppy disks in some of their specialized computers, like for controlling
nuclear missiles and things like that. Well, is that a problem? Not necessarily, you see
those drives and disks were actually extremely reliable back in the 70’s and 80’s. Of course,
they also used to be expensive. A box of 10 floppy disks could actually set you back.
In the 90’s they started making them cheaper and cheaper and the reliability suffered.
And by the 2000’s when the last batches were being produced, they were total junk. The
last few boxes of disks that I’ve bought, probably around 2005, probably some of the last ones
you’d find in a computer store, they were actually Sony brand, a brand that you might
think would be of high quality. And they were total junk. In fact, 3 or 4 disks out of each
box of 10 didn’t work right. “One of the things I think that people don’t realize now is just
how much floppy disks actually cost back then. You know, you can go now to the store and
you can buy like a spindle of 50 CDs or DVDs for like $10. Which, I know they’re also on
their way out. But, you know, back when I was a kid and I was using computers like in the
late 80’s and the late 90’s, you could easily drop $20 on, like a 10-pack of floppy disks. And really
by that time, the price had already come down, before that they were even higher. And it
was expensive enough that I actually had to ask for a box of disks for Christmas.” I think
because floppy drives and the disks had become so unreliable towards the end of the era,
I think a lot of people remember them that way, even though they were actually pretty
darn reliable back in their heyday. In fact, I have plenty of disks that are like, over 35 years
old and they still work just fine. “I’ve got some floppy disks that have survived since
the late 1979 from Heathkit systems and they’re still fine. On the other hand, I’ve got floppies
from 1999 and they didn’t last until like 2003 and they were done. Toast. And I lost
a bunch of cool stuff. But, that’s how it goes. That’s kind of a thing that’s unfair
to floppy disks. I think if you take care of them really well, at least from the ones
I’ve got in my collection, they tend to last for a really long time.” “As a retro computer
collector in 2016, let me just tell you that dealing with these aging floppy disks is a
huge pain in the butt. However, there are solutions like floppy drive emulators now
that make working with these machines a lot easier. But I have to say there is something
comforting, and nostalgic about hearing. [FLOPPY DRIVE CLICKS] That sound.” And if you want to really appreciate
floppies, just compare them to tape drives, or even worse, to these old punch-tape reels
that were incredibly noisy. Of course, floppy disks were eventually replaced by optical
media such as CD-ROM, which is a tale for another episode some other time. But one thing
I can say for sure is that the track/sector concept we talked about earlier lives on today
in magnetic hard drives only the data is so much more densely packed. Now, I suspect in
another 5 to 10 years, everything is going to be solid state and think moving disks,
like hard disks and stuff like that are going to be obsolete forever. Edited and improved by: OPGuyK

About James Carlton

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100 thoughts on “How Old School Floppy Drives Worked

  1. Yahu oyunu alırdık eve gelene kadar bozulurdu. Ama bir iyi yönü vardı scandisk ile onarılması gayet basitti. Şimdiki cd ler bozulsun bak bakalım varmı geri dönüşü 🙂

  2. I used this in 1986 i start programming with basic cobol and others i diseigned my first space s game played with joysticks at my 16 years old 1987 it was amazing
    But very hard when Waiting a 2 hours for the tape To be read and at 98% load crash error 400.. wow
    I thnik guys of my generation is gladiators of computer sciences without our courage hard work nothing of all of this technologies can't exists 😂😂
    Hi To 1960 1970 générations
    And thanks lot for this video

  3. My Amiga 500 and diskettes were my attic, in the Florida heat and humidity for 15 years. It still works, and ALL of the diskettes are still readable.

  4. i spent 7 years on nuke subs and yes the 24 icbms we controlled by 8 inch floppy man those were the days to bad i got hurt now i just sit around and watch YouTube videos like this.

  5. 3.5 floppies (or discettes) are not dead yet. I have a friend working in a very large steel company (really not gonna name them as it's just embarrasing) and they use those floppies still today to transfer cutting instructions from the designers for the men operating the laser or water jet cutters. It was funny at first but now it's just sad to think about how much trouble they are going be when those floppies wear out….

  6. Be careful with that program that that plays music through the floppy drive cus doing it too much can break the read head

  7. I thought magnetic storage had a shelf-life? Like even that good shit from the 70's will be unreadable by the 2030's? Not that it won't have been archived but still.

  8. 1:32 Asiaton oleskelu kielletty.

    I've never seen those huge 8" disks! When we were kids, only one guy had a disk drive for his C64, all the rest of us had a tape player.

    Floppy disks are cool. There are disks of the same size, but the ones that work on a C64 are different than the ones suitable for a PC, I reckon. Although they look the same, that is.

  9. 3.5 inch floppies, also known as crunchy disks.

    Sucks I didn't find that name out until after their decommissioning.

  10. 0:58 or, it could be showing the amount of time he was using his equipment, hence his speed and ease at working with it… low-tek style…

  11. Fun fact; in the Amstrad CPC 464, there was no disk ROM, meaning that if you added an external disk drive, it had to have its own disk ROM or the CPC didn't know what the shit to do with it. This meant that a drive intended for the 464 couldn't be used as a second drive on the CPC 664 or 6128, which had disk drives built-in and thus had disk ROMs already; the external drive's disk ROM would conflict with the internal ROM. So a drive which was intended for use with a 464 needed its disk ROM disabled before it could be used with the 664 or 6128.

    Interestingly, when Amstrad redesigned the CPC for the Plus models, they included the disk ROM in the 464 Plus despite it not having a disk drive. This meant they had the same problem as the 664 and 6128 if you wanted to use an external disk drive.

  12. Check out this old memory from 1986 (?). The Silicon Disc. A memory flash drive where you can stack flash cards with 500Kb of RAM For IBM and Atari. https://www.youtube.com/watch?v=f9fw5Dqs81k&t=911s Sorry guys Dutch only

  13. "people calling 3.5inch floppies harddisks"…. haha yeah…. when they're actually called DISKETTES! but who am I to talk…

  14. This was a great description of life with floppy drives. Every time I thought about something I could leave a comment on, you'd cover it. It was great to see one of our old Q-Link disks. When Quantum licensed the software from its developer one of the first tasks was to write a fast loader. The original software took four minutes to load and access a content area.

    The only thing you could have elaborated on was how those unsupported tracks were used for copy protection. I had to take my 1541 apart a couple times after EA locked up the head while I was exploring. 😉
    I recently took my C= equipment out of the attic (motivated by The 8-Bit Guy) and was equally surprised that my 30-35-year-old floppy disks still worked fine.
    BillP

  15. i think hard disks will last 20 years more because they are their sizes increases considerably over time, pretty useful in situations when size matters over perfomance, also they are super cheap and reliable, they are good for backups or just storing data.

  16. The last "batch" of 3.5 floppy disks (disquetes/disketes) here, on Brazil that i got for my old 2000-2005 computer were get on 2011-2012. I had a place that had them stored somewhere in the back of the store for a long time, it was a Sony one if im not wrong. I only used that 2000-2005 computer for old games and for destroying it OS xD (Windoes 95, 2000, ME, Dos, everytime a "new" OS was on it). I had a new PC, but i liked the old white/yellow guy. I was 12 at the time i got the floppys, the old pc was older than me, but not by much.

  17. Will they tho? because if something happens to ssd it's all gone. In case of optical mediums – you can always retrieve some data. So ssd-s are not recommended for long term storage fo example

  18. The computer I use every day is 7 years old smh. Slow as hell and the screen is broken but I'm going to be genuinely sad when it dies.

  19. Ah, reliability. I have a Commodore PET and 8050 floppy drive that I've had since it was made. And almost all of the disks from the early 80s are still readable. And the drive is still apparently aligned pretty well. Quality, folks. And the IEEE-488 bus used by Commodore peripherals (also known as GPIB, which means "general purpose instrument bus" I believe) is still in use for test equipment. Though I think Commodore used their own version of it. Still, the cables are at least the same and can still be found.

  20. I remember getting about 30 3,5'' floppies with games from my friend, most of them didn't even work. Damn I just checked the price now and new ones are freaking expensive!

  21. Unfortunately I was born in 1987 so I didn't see any of this until the early 90's. My first exposure to floppy disks was when my dad brought home an Amiga A600hdwith a 3 1/2 inch when his work upgraded to windows 3.1. In 1996 we got our first PC with windows 95 with a 3 1/2 inch floppy and a 4x CD drive

  22. Hard disks have an advantage of SSD's that may prevent them from ever being replaced. SSD's data will decay over about 10 years when powered off and thus should not be used as a means of archiving data.

  23. We had so many types of storage over the years. I never had Floppy Disks, so I thought that they were the same as DVDs, with the only real difference being that you could change the Data on Floppy Disks and not on DVDs. What I had instead of Floppy Disks, is USB sticks.

    These are USB 2,0 Sticks. Not, that you read this comment, and think that I might had USB 3,0 or USB C sticks when I was little. I might have them eventually, but definitely not when I was little.

  24. Well, 3.5 years later: SSDs have pretty much dominated the market. Consumer market totally in under, say, 500GB range, but above that it's just so much cheaper to get a spinny thing. Servers and storage servers, even small NASes, however, are a different story.

  25. ♫ "All I Want for Christmas" ♫ (geek remix)

    My Atari stops and blinks at me

    These two disks are gone as you can see

    I don't know just who to blame for this catastrophe

    But my one wish on Christmas Eve is as plain as can be

    All I want for Christmas is my two floppy disks
    My two floppy disks
    See my two floppy disks
    Gee, if I could only have my two missing disks
    Then I could play you, "Merry Christmas"

  26. Imagine that you're a commodore user and you go over to your friend's house to see his new apple computer, and on boot the floppy makes the same noise as it does when encountering a read error, and you immediately freak out

  27. I worked at Verbatim when they were called Information Terminals and their floppy line was called Verbatim. They took off so quickly that the company changed its name. Then I moved to Dysan where they were playing with making 5 m/b floppies for commercial use. I still have a box of them just so I can say I have them. I remember people thinking they would get double-sided floppies by cutting the notch in the opposite side of the jacket. Funny thing was that if we tested the floppy for failures on both sides and only one side passed, that side was notched…not both. When we learned that people were notching both sides it cracked us up knowing that sooner or later there would be a data drop due to the side failure

  28. Hated 5.25"s, so vulnerable and papery. My first PC (1991) would have come with both 5.25" and a 3.25" drives but I told them to omit the 5.25 even though it cost me the same. The internal ATA ribbons for floppies had the first connector for the 5.25 and the second for the 3.25 with a nasty twist in between. Pity the 3.25 wasn't the first connector as then I could have cut off the further part to save clutter.

  29. 12:35 My daughter who is three was shouting Mario Mario! Considering I have never played the game, I think she was a gamer in her previous life!

  30. Floppy disks are in my heart and they will never die.
    Btw i got some floppy disks, there were around when i wasn't even born.
    Geez, old times. Im excited to use them.
    And if they die, im going to keep them.
    Floppy disks <3

  31. I definitely remember using the 3 1/2 way more than the other two. And in fact, only ever saw never used the 8-inch drive. Then again I wasn't born till 92.

  32. My first encounter with 8 inch floppy came when I bought my floppy disk drive for my Atari computer I was about 13 at the time. My aunt, living in Texas, worked for TI for a while. She heard I purchased a floppy drive and sent me an 8 inch floppy disk. I knew something wasn't right the second I opened the envelope. This thing looked huge to me. I took a double take because at my young age I only thought there was one format for floppy disk and that was the 5.25 inch. I took the disk to my bed room and set it on top of my Atari 1050 and sure enough it covered the entire top of it. It was years later before I actually got to use one of those bad boys in one of my television production classes on the old Chyron graphics machines. (If you watch early episodes of WKRP in Cincinnati you can see the actual font used by one these machines in the end credits).

  33. Another great video! There is a machine at my former employers that is still running on first generation fanuc software and has the machine parameters stored on punched tape. The tape would run through the reader in the front panel into a bin in the bottom of the panel door (!) then wind itself back up onto the spool.

  34. Bro be careful with that software that makes the drive play music you can burn up the read head and break the drive if you do it for too long

  35. Super'man' memory crystals is on it's way, I wonder when it will be out for commercial usage though. Hopefully within the next 5-10 years, because I'm really tired of buying new harddrives all the time, since the data is getting bigger and bigger it's becoming a problem.

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