That toasty head coil suggests to me that there may be a problem with head bias, and the board is providing way too much current. If so, it could end up toasting the head in the other drive.
Marc. I would be a little wary of the "good" board from the drive with the burned up read/write head. You had a problem writing a disk with it?.. I would find some way to check the write current being sent out to that head.
I am amazed at how much interpretive knowledge is available for CuriousMarc when he looks at a piece of electronics, or the schematics to one. I grope as a blindman in comparison.
13:50 - "No (scratching) noise" That's something we should remember: If you hear noise coming from it, don't use any other floppy before a very good cleaning. Trying to read old floppies, I didn't realize some mold on surface on the first, drive and floppy made some noise, got no reading back and I inadvertently changed to another floppy. Result: two "sandpapered" floppies.
It's neat seeing this old equipment. I get a kick out of those massive stepper motors they used in those. Assuming nothing goes horribly wrong in the driver circuit and cooks them electrically, I imagine they ought to work for a long, long time. It's really nice to see you were able to salvage quite a bit out of the collection.
9:00 - I did a double take at the SDP/SI invoice address. So random to see a business from my home town. I drove past that place every day for years on my commute, and didn't know they existed until now. Oh and great video as always, Marc!
I love watching these videos. Word of caution, though, about that steel band watch you wear. Back in the 90's, one of my colleagues blew up our second-to-last trade show prototype board, along with a few thousand dollar, long-lead-time FPGAs, when his watch accidentally shorted the power input section of a large board in our development chassis. I've put my watch in my pocket when I'm in the lab ever since.
normally those watchbands are made of aluminium or something exotic - as steel is quite heavy - but the problem with conductivity is the same. This also goes for jewelry, like rings etc, as they're also quite conductive and it's entirely possible to short something out if you accidentially touch the wrong thing
Marc is an 8" floppy drive repair shop! I wonder if those heads are difficult to rewind with the fine enameled wire? Otherwise the only way to acquire another working head is to cannibalize another 8" drive. I don't believe there are any companies selling parts for those obsolete 8" drives. I remember all the boxes of thousands of 8" floppy disks we had when we used the IBM Displaywriters in all of the offices. And all the supplies for the daisywheel printers we had. So much stuff went to the warehouse, to be sold by the pallet to e-waste companies. 😢
The entire CuriousMarc team need to have their brains digitized before they go - which I of course hope is a long, long way away. The world ever losing this level of knowledge, skill and particularly insight is simply unacceptable.
Same tenacity I exploit when restoring old radios and transceivers. Few electronic devices are unrepairable if you have the time ,resources and patience.
@@GadgetUK164 No way.. The amount of entertainment / information that you have provide me over the last few years. Those few works are not enough. Is that the Cheque in the post now 🙂 .. Te, Te.. You Deserve the praise mate. Keep up the good work ... Cheers
Broken in new and entertaining ways? No doubt, nothing ever falls into a good pattern or groove. It's all new each time. But great to see you were able to get going without using the motor brake, and test more drives quickly.
I think it is worth repairing/ cleaning that "dirty" control board , and checking the one off the burnt head one (Reading others comments). Other than that it is always worth having more working disc drives - inc fixing that noisy motor too ( though might be worth sending that to other people if time is a long constraint) Check two more drives before going onto your hp project.
This reminded me of when my brother lent me a "Discworld" book; I just couldn't hack it. "Believe it or not, I have seven more, but...' Perhaps Terry Pratchett would have appreciated the unintended comedy in that statement.
Probably! That would be very difficult though. If that was my last head I would have had to do that. But fortunately I have plenty of other floppies around to steal heads from...
Do not put the burned Coil Board in the good Coil Case, bro... it will burn out the "new" coil too, thats wy you have trouble with your disks after "repair"
Same here. Playing at 1.75x and wearing headphones my cat started looking around. I had to test of course, rinse and repeat the cat kept looking each time.
oh, I'd been afraid of using the board of the drive with the burnt coil. I'd suspected an amplifier failure that burnt it.... but I don't really have any expertise in this XD
Better to have a single working unit rather than two damaged ones... Nice troubleshooting and pity about that head. The motor could probably be recombobulated.
Great video as usual! By the way the subtitle timings are significantly better this episode, almost perfect, except for the segment between 21:05 and 21:40 where some of them (I think just "I don't think I have the sound..." and "Oh, oh" are on screen for too long.)
I don't know about 8" drives. But I have had a few 5.1/2" drives that I thought was bad. Nope just needed a good cleaning. Just hard gunk on the head. As for alignment . You have a o scope and maybe an alignment disk?
5.25" drives are loads simpler than 8". Much more standardized design and somewhat able to realign themselves, especially the HD drives since they were made to read several different disk formats. 8" is much more mechanical and I believe Marc's way of aligning them with the oscilloscope is the only way to do it, it just requires a known good disc
If those are sealed bearing in the motor just measure there inner and outer diameters of the bearings. then find a local bearing shop and you should be able to buy new bearings.
he guessed the brake is there so the motor doesn't overstep when it's unpowered and I agree it's likely there more as a safety when transporting the units, than it's required for operation.
![EarthBound - Happy-Happy is Blue [Oscilloscope Deconstruction]](/img/n.gif)
That toasty head coil suggests to me that there may be a problem with head bias, and the board is providing way too much current. If so, it could end up toasting the head in the other drive.
I completely agree. Saw it coming from a mile!
...bias? On a floppy read/write head?
Marc. I would be a little wary of the "good" board from the drive with the burned up read/write head. You had a problem writing a disk with it?.. I would find some way to check the write current being sent out to that head.
That's a good point. Let me check that the next time I fire up that board.
I am amazed at how much interpretive knowledge is available for CuriousMarc when he looks at a piece of electronics, or the schematics to one. I grope as a blindman in comparison.
13:50 - "No (scratching) noise" That's something we should remember: If you hear noise coming from it, don't use any other floppy before a very good cleaning.
Trying to read old floppies, I didn't realize some mold on surface on the first, drive and floppy made some noise, got no reading back and I inadvertently changed to another floppy. Result: two "sandpapered" floppies.
It's neat seeing this old equipment. I get a kick out of those massive stepper motors they used in those. Assuming nothing goes horribly wrong in the driver circuit and cooks them electrically, I imagine they ought to work for a long, long time. It's really nice to see you were able to salvage quite a bit out of the collection.
That Windows 95 boot sound activated so many memories...
9:00 - I did a double take at the SDP/SI invoice address. So random to see a business from my home town. I drove past that place every day for years on my commute, and didn't know they existed until now. Oh and great video as always, Marc!
Marc, you're missing a BIG opportunity here: RAID those 8" floppies! The sounds of a 10 8" disk RAID array would be heaven! :)
Floppotron: *MOAR BASS*
I love watching these videos. Word of caution, though, about that steel band watch you wear. Back in the 90's, one of my colleagues blew up our second-to-last trade show prototype board, along with a few thousand dollar, long-lead-time FPGAs, when his watch accidentally shorted the power input section of a large board in our development chassis. I've put my watch in my pocket when I'm in the lab ever since.
Whoa.. more knowledge from experience. Thanks for sharing
normally those watchbands are made of aluminium or something exotic - as steel is quite heavy - but the problem with conductivity is the same. This also goes for jewelry, like rings etc, as they're also quite conductive and it's entirely possible to short something out if you accidentially touch the wrong thing
@@thesteelrodent1796
They are stainless steel most of the time. Doubt aluminium is the norm or even close to it.
I knew an electrician who did the same with mains voltage once - he always wore a plastic watch after that.
Nearly blew myself from the top of a step ladder by putting my wedding ring across 20.5v and GND. It stayed at home ever since then.
Marc is an 8" floppy drive repair shop! I wonder if those heads are difficult to rewind with the fine enameled wire? Otherwise the only way to acquire another working head is to cannibalize another 8" drive. I don't believe there are any companies selling parts for those obsolete 8" drives. I remember all the boxes of thousands of 8" floppy disks we had when we used the IBM Displaywriters in all of the offices. And all the supplies for the daisywheel printers we had. So much stuff went to the warehouse, to be sold by the pallet to e-waste companies. 😢
The entire CuriousMarc team need to have their brains digitized before they go - which I of course hope is a long, long way away. The world ever losing this level of knowledge, skill and particularly insight is simply unacceptable.
Same tenacity I exploit when restoring old radios and transceivers. Few electronic devices are unrepairable if you have the time ,resources and patience.
i wish i have knowledge like you.
We need engineer who can repair and preserved vintage computer devices like you.
Wonderful work as always! You have the best retro tech channel hands down!
Yes on that side of the pond. But this side.. more like it's you, who has the best channel. 🙂
@@thepumpkingking8339 Thanks, you're too kind!
@@GadgetUK164 No way.. The amount of entertainment / information that you have provide me over the last few years. Those few works are not enough.
Is that the Cheque in the post now 🙂 .. Te, Te..
You Deserve the praise mate. Keep up the good work ... Cheers
First time seeing a read write floppy drive head coils under a microscope!
Well done!
Broken in new and entertaining ways? No doubt, nothing ever falls into a good pattern or groove. It's all new each time. But great to see you were able to get going without using the motor brake, and test more drives quickly.
😂 Are you trying to corner the market for 8" drives?! Amazing lollipop stick brake mod 👍👍. On to the next video in the series 😊
Who would have though 8" floppies were this interesting in 2023.
I think it is worth repairing/ cleaning that "dirty" control board , and checking the one off the burnt head one (Reading others comments). Other than that it is always worth having more working disc drives - inc fixing that noisy motor too ( though might be worth sending that to other people if time is a long constraint) Check two more drives before going onto your hp project.
Repairing floppy disks by Curious Marc. And the world is OK again.
Impressive!
Nice work as usual!
These look so much fun
love these hp videoes the best!!!!
looks great, I thought that read head with toast for sure.
This reminded me of when my brother lent me a "Discworld" book; I just couldn't hack it.
"Believe it or not, I have seven more, but...' Perhaps Terry Pratchett would have appreciated the unintended comedy in that statement.
Can one actually repair--redo the wee windings of?--that upper head on Drive 4? Part 3 of the video series: Microsurgery
Probably! That would be very difficult though. If that was my last head I would have had to do that. But fortunately I have plenty of other floppies around to steal heads from...
We need ways to wind small heads!
Sterling Instrument actually makes their own linear rails.
@Marc, Dave from Dave's Garage is 'seeking' an 8" drive for his Kim-1 computer.....
Do not put the burned Coil Board in the good Coil Case, bro... it will burn out the "new" coil too, thats wy you have trouble with your disks after "repair"
Strange that there is something comfortable about seeing Abort, Retry, Fail? 😅 I sure miss the sites and sounds of early hardware!
At 17:55 my cat was laying on my desktop, snoozing a bit.. When the drive made the terrifying noises, she quickly jumped away.. :)
Same here. Playing at 1.75x and wearing headphones my cat started looking around. I had to test of course, rinse and repeat the cat kept looking each time.
5:40am and I am the first... insomnia pays off finally :)
UA-cam says second, but you are nevertheless awarded bad 8" floppy magnetic material, full of vintage bit errors. Nothing but the best.
@@CuriousMarc well it took me too long to type.... I am an old mechanical teletype AI - Autonomous Intelligence ;)
I want to see what Spinrite 5 and 6 would do with these drives!
4:59 Brian Eno's shortest composition!
You know when you are working with floppy disks, good dollop of spit (19:50) works wonders.
A big advantage of these drives is that they are highly portable. 😂
DJ Curious on the Disks
oh, I'd been afraid of using the board of the drive with the burnt coil. I'd suspected an amplifier failure that burnt it.... but I don't really have any expertise in this XD
Good rule of thought... You don't know where that drive's been! Practice Safe Computing! Clean the heads before use.
Next challenge -- rewind the burned head. :-)
Exist today new 8 inch's new diskettes?
was that a silicon on sapphire PHI chip on the HP-IB board?
Better to have a single working unit rather than two damaged ones... Nice troubleshooting and pity about that head. The motor could probably be recombobulated.
Осталось вспомнить диски от СМ-4)))
Great video as usual! By the way the subtitle timings are significantly better this episode, almost perfect, except for the segment between 21:05 and 21:40 where some of them (I think just "I don't think I have the sound..." and "Oh, oh" are on screen for too long.)
I don't know about 8" drives. But I have had a few 5.1/2" drives that I thought was bad. Nope just needed a good cleaning. Just hard gunk on the head. As for alignment . You have a o scope and maybe an alignment disk?
5.25" drives are loads simpler than 8". Much more standardized design and somewhat able to realign themselves, especially the HD drives since they were made to read several different disk formats. 8" is much more mechanical and I believe Marc's way of aligning them with the oscilloscope is the only way to do it, it just requires a known good disc
I wonder if the heat damage was from friction, Is it on the side that was dragging?
I was thinking that too. Or, inversely, the heat from the head caused the disk material to melt.
If those are sealed bearing in the motor just measure there inner and outer diameters of the bearings. then find a local bearing shop and you should be able to buy new bearings.
has Marc ever mentioned what kind / model of microscope he uses?
I have a Bausch & Lomb StereoZoom 4 (the binocular microscope) and an Olympus BH-2 (the metallurgical microscope).
I don't always watch these super closely but did you explain why the brake was unnecessary?
he guessed the brake is there so the motor doesn't overstep when it's unpowered and I agree it's likely there more as a safety when transporting the units, than it's required for operation.
longing
Please note : someone is posting continually here about having Ovarian cancer and looking for donations. Needless to say it's a huge scam.
Ohh first
You are first! You get free weak vintage bits from an 8" floppy disk damaged by a rubbing head.
Dave plumber is looking for a shugart 8” drive. @davesgarage