foone Profile picture
9 Jun, 29 tweets, 7 min read
does anyone remember what year it is
because I apparently don't
I'm not an expert but I don't think floppy drives are supposed to sound like this
that's even less what they're supposed to sound like
Here it is with the top removed.
This is a Futjitsu M2551A drive.
So right here there's a track-zero sensor. That thing on the left is an opto-interrupter/photo-interrupter. Basically it's an LED and a light sensor. If it can see the light, it knows there's nothing in the way. if it can't, something's in the way.
And the drive head mechanism has a little "wing" that sticks out to fit into that sensor.
The drive head position is controlled with a stepper motor (here on the bottom), but that just means it can move a track up or track down. It doesn't know WHERE the head is.
that's what the track zero sensor is for. Basically if the drive controller is ever told "go to track N" and it doesn't know what track it's on, it instead tries going down a track forever. Eventually it'll hit track 0, and know it's there because of the sensor.
then it just needs to move up a track N times.
The controller remembers which track it's on, so if you then tell it to move to N+1, it just goes up a track, rather than doing this zero-seek all over again.
it seems what's happening here is that the opto-interruptor isn't working, so the drive controller starts trying to seek down to get to track 0, and the physical head eventually gets there, but the controller never knows it's there.
thus the BZZZT noise as it tries to seek to track -1, which is physically impossible
this sort of thing is why the Apple II disk has that very distinctive chattering noise. Instead of a track 0 sensor, it just seeks down enough times that it knows it's at track zero, because it can't physically move past that point. It does this by banging the head into the case
and sounds like this:
So opening it up and doing a little cleaning seems to have fixed the BZZZZT and it can seek now, but it's not able to read any sectors or write any sectors. Seems it's dead.
so yeah, all of those drives are either broken or not the kind I need.
THAT'S OKAY, I have alternatives I can try.
hmm. I think my disks might be bad. several of them can read my test disk, but then when I try to format a blank disk, they make it 17 tracks in and start throwing errors

maybe track 17 is just bad ?
I'm using official IBM disks, though. how can they be bad?
also apparently one of these attempts at formatting B: unpartitioned my C:

I'm not gonna ask exactly how that happened
fortunately this is a test system so I didn't lose anything
the fuck, IBM? Are you really worried that people with hack into your floppy drives?
fortunately I am nothing if not a person of screw bits
it's all metal inside.
here's where the big cable comes in
I like how they locked the case with security bits and still put a voltage warning inside.
Never change, IBM.
yeah that screw is going to be fun to get out
And it's out!
And this is apparently a DFC642B09A, which is supposedly a 1.2mb drive!

WHAT
yeah this is the 4869-002, not the 4869-001. So it's the 1.2mb HD drive, not the 360k DD drive.

Fuck.
ok closed it back up.
minus those security bits, because fuck that.

• • •

Missing some Tweet in this thread? You can try to force a refresh
 

Keep Current with foone

foone Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

PDF

Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @Foone

10 Jun
Today I may get to document a previously unknown type of floppy disk.
It's a good day to be a Foone
Ever seen one of these before? Image
here it is next to an 8" (NOT a 5.25"!) disk
this is officially a Huge Motherfucker of a disk. Image
Read 38 tweets
10 Jun
Opening up a snowball USB microphone.
Fun fact: it's screwed and then TAPED together. Image
It's apparently an ICE-6327, or a P2FH31497A0 Image
So the main chip is a Cmedia CM6327A, which is a USB Mono ADC with USB interface.
This thing is designed to interface with an external EEPROM to get configuration info like product string and USB VID/PID, or you can have another microcontroller talk to it over i2c Image
Read 12 tweets
10 Jun
I MUST KILL THE PRIME MINISTER Image
This is software for the videonics DirectED video editing device. The software loads from vhs tapes, and consists of a bunch of flashing black and white rectangles.
I'm only like 90% sure it's not trying to hypnotize me
Read 4 tweets
9 Jun
I think my 3d printer's camera may be misaligned Image
It just sent me an update saying that the print is done, and included this picture of the final print. Image
I knew it was a mistake to try to print on the ceiling
Read 15 tweets
9 Jun
I wonder if anyone has tried retrobriting new hardware.
It's rare but they do make new beige stuff.
Why not retrobrite it?
It'd be useless of course, but it might be interesting as an experiment. Like some people worry that retrobrited stuff gets yellow again faster? Retrobrite a new beige thing and keep another as a control, and wait.
Read 6 tweets
9 Jun
I don't support this kind of trolling, so I'm not going to retweet this without commentary. This is fake, intended to make you go check and end up rickrolling yourself.

Which I do support, so...
Also when I typed "rickrolling" my keyboard didn't have it in the dictionary, so it suggested "rickroll ingredients"

Swype... Do you think the rickroll is like a California roll or a dinner roll?
Suggest the ingredients for a "Rick roll" sushi roll
Read 5 tweets

Did Thread Reader help you today?

Support us! We are indie developers!


This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Too expensive? Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal Become our Patreon

Thank you for your support!

Follow Us on Twitter!

:(