This gave me such a warm fuzzy feeling for some reason. Just like every piece of ancient hardware I manage to make come back to life. I didn't know this feeling could be enjoyed secondhand. :B
When I was operating a computer shop between 1997 and 2000, I had a customer who bought for the price of iron old MFM drives like those ones. He saved the stepmotors for his robotic projects. I can also see many DIP components which can be useful for personal projects
Tantalum capacitors have the bad habit of clearing themselves from time to time. If placed on a low impedance line, they short the power supply and may kill themselves too. They were invented for timing purpose and power filtering (where there is a resistor in series). Some designers (most famously, an HP line of instruments with communication bus) didn't know tantalum capacitors well, and were splurging on them. The designers of this hard drive were part of that category, placing a tantalum cap in parallel to power line. Nowadays they have been replaced with multistrate ceramic (non-electrolytic) capacitors on all modern hard drives. Thanks for the video. I think was year 1992-3 that we used MFM (modified frequency modulation) hard drives, soon overseded by RLL (run length limited), and soon after, drives made their own sector translation, so to place more sectors on the external disk tracks: MFM and RLL had the same number of sectors on the first and the last track...
Wow that is beautiful, I have a large ex server drive that I think I've lost the MFM controller for Used to spin it up just for the sound of it, great to see you know so much about the hardware and how to repair it as well, and wow that old 386 bios... I have played in them!!
So cool. Around 1993 I bought very similar hard drive, but it was already mechanically destroyed, probably by a virus. I still have motors and damaged disc plate...
Some stepper and servo motor drives (yes, servo motor drives exist) are self-parking. Many Miniscribe ones will self-park after a period of inactivity. Many Seagate stepper motor drives will use the inertia of the platters to generate electricity to park the heads; I believe the ST-251 was the first to do this.
Excellent work, you save that piece of computer history from the shreder!. i still have an old 286 motherboard with the same BIOS to do low level format. I recently bought an IBM Thinkpad 770X from a guy in Germany, the laptop is in very good shape but the original hard disk worked some time and started to slow down and showing bad sectors, i'm going to use the old board, maybe i can repair it?
Been decades since I had to low level format an RLL/MFM drive, I seem to remember you used to use the debug command to access something on the controller card?
I seem to recall the Dos command Debug and then g=c800:5 would initiate a low level format under various dos versions, Debug was quite a good tool back then.
Thanks for your very nice videos my fellow Retro friend, you have gained my subscription! I would love if you could dive deeper in the meaning of the CHS stuff (Landing Zone, WPcom...), I never know what those are or where to find the information on the drive...
Cylinder, Head, Sector. On those older drives, those are usually printed on the label. If the label is gone/damaged you would be on a wild goose chase to find that now days. I just barely remember that stuff, because it became "automatic" about when I got into it. Only 2 reasons I remember is because I needed to know them when drives went over 512mb capacity, and I had a 386 with faulty CMOS battery wiring (wasnt a battery issue, bad board, eventually used AA batteries & didnt solve it). DISCLAIMER- I was a kid back then. They referred to "how many rings", "how many blocks per ring", and "how much data was in a 'block'". As I recall. I could be wrong, but I remember entering those numbers every day. Eventually got a 486, and after that, an "overdrive" cpu. One day I got a P3 "coppermine" and thought I was king of the world for a minute.
I would not want to run 95 on a 386. I can remember running Windows 3 on a 286 with 1MB - it was a sample machine and only had the 1MB (640k plus BIOS shadow), and the rep that brought it said real mode wouldn't be great... Standard mode, I said, and went into BIOS to swap the 384k from shadow to extended, which surprised him as he never knew it could do that ... many systems in that era could, but ONLY with 1MB - with more, the shadow cannot be reassigned
I have one of these drives faulty. It spins up, but it over speeds well past 3600 rpm and is not stabilizing. Would like it back since it was my fastest half height MFM drive.
I have a Seagate ST-1100 with a very weird behaviour. If I terminate it correctly (no termination on that one, and one on another drive at the end of the cable), I can format with head 0 and that one only - it even boots from the drive like that. When I change termination settings, I'm able to format with heads 2-7 apparently successfully, but not 0 and 1 - which makes the drive fail since track 0 is unavailable, of course. Depending on how I install and terminate different drives, it gives a different result, so my conclusion is that it has something to do with improper termination for some reason. Do you have any suggestions as to what might cause this behaviour?
It’s amazing how it can be in such a wonderful state of being a very old hard drive. Where can I get such old hard drives most of my childhood recalls. I also collect such old working capable hard drives. I have a Quantum Big Foot 5.25 inch hard drive. I would be very interested if you could get such old hard drives to Hungary by post relatively cheaply. Thanks in advance too.😊 Please more more such videos.😊
Man i wish i could send you my MFM hard drive for repair. It doesn't spin up at all. I checked and checked nothing seems shorted and yet it doesn't start. The heads weren't stuck to the platters so it's wasn't that either i just don't know what to do. Tips?
easily back in the time. No internet, no mp3, no HD graphics, almost no graphics😂, no multitasking, simple GUI, games with 320x240 resolution, not 1000 threads hidden running behind your OS.... I know, younger generations might ask themself: what the hack were you doing with a computer back in the days... well, word processing and printing on endless paper with a 9 needle printer... playing prince of persia and programming assembler... 😉
hola tengo un seagate st225 y una controladora LSD-6210 REV A3 pero el disco no me lo reconoce y cuando pongo el nombre debug y el comando se queda sin responer que no hace nada como pc uso un pentium iii desabilitado todas las controladoras internas de la placa pero nada y configurando los c-h-s en la bios pero nada podrias ayudarme
MayB a long time after this video, made me realise; how far Amiga & SCSI ws, back then. If they 2gether were appreciated more back then, the world would actually B totally... different. Maybee an apple 4 di... eye! Namasté.
I think the head was stuck so it wasnt moving and the coil took so much current it melted the cable Edit. Ok I was wrong, it was one of those famous tantalum caps
@CPU Galaxy Hard disks has capacity - not memory if you talking about max. space on it... Memory is used when you want to say how much megs/gigs of RAM you want install or how much is already installed on the motherboard or how much for example cache CPU have...
As said in the video, without the matching controller the data is unreadable. Disk and Controller build an Team which can't be separated or you loose the data.
![286 Board Restoration & Testing [Leaking Battery and Exploding Caps]](http://i.ytimg.com/vi/kpQEhJNrJA8/mqdefault.jpg)
Just so you know, Dave at EEVblog brought me here and now I'm binge watching all your videos. Fantastic content.
When electrolytic capacitors and tantalum caps die, they can take out PCB tracks.
Nice repair and great video!
Thank you so much for doing this video in English. It was very enjoyable. I plan to play around with my old ST-225 soon.
How did that go?
Well never know
Still haven't. It is still sitting on shelf lol
@@custm42435How about now?
I have the SCSI version of this drive with the same symptoms, so you likely just saved me a lot of time on the repair, thanks!
The sound of an old hard drive always reminds me of my first computer. I got a Tandy 1000 sl in 1988 when I was 12-13
This takes me back many years... I used to get MFM drives out of the rubbish at work... take them home and try to get them working...
This gave me such a warm fuzzy feeling for some reason. Just like every piece of ancient hardware I manage to make come back to life. I didn't know this feeling could be enjoyed secondhand. :B
I hope you can do more hardware repair video`s, id really like them and can learn from them as well. Subscribed and notification bell added.
This brings back memories :o) I remember my first DOS computer, it had a HDD that was a MASSIVE 5Mb in size!
You know what's really massive?
Btw, the smallest hard drive size that DOS machines ever came with was 10 MB.
Great video, I love mfm hard drives. Fascinating stuff.
You given me back my old memories! Thank you!
This is Win :) Wow your video is really good quality and the tutorial is clear and easy to understand. Thanks for the knowledge sharing video.
Winict Maximus Cosmo Hi Win, was very nice to get to know you in the middle of Bangkok. Thanks for the feedback and see u again. 😉
Thank you for this detailed video I enjoyed every second. You got a new sub, and a new Greek fan :D
thank you ☺️
Thanks for a lot of great videos. I was brought here by Dave from EEVblog, one of the better chistmas gifts.
When I was operating a computer shop between 1997 and 2000, I had a customer who bought for the price of iron old MFM drives like those ones. He saved the stepmotors for his robotic projects. I can also see many DIP components which can be useful for personal projects
Tantalum capacitors have the bad habit of clearing themselves from time to time.
If placed on a low impedance line, they short the power supply and may kill themselves too.
They were invented for timing purpose and power filtering (where there is a resistor in series).
Some designers (most famously, an HP line of instruments with communication bus) didn't know tantalum capacitors well, and were splurging on them. The designers of this hard drive were part of that category, placing a tantalum cap in parallel to power line.
Nowadays they have been replaced with multistrate ceramic (non-electrolytic) capacitors on all modern hard drives.
Thanks for the video. I think was year 1992-3 that we used MFM (modified frequency modulation) hard drives, soon overseded by RLL (run length limited), and soon after, drives made their own sector translation, so to place more sectors on the external disk tracks: MFM and RLL had the same number of sectors on the first and the last track...
Wow that is beautiful, I have a large ex server drive that I think I've lost the MFM controller for Used to spin it up just for the sound of it, great to see you know so much about the hardware and how to repair it as well, and wow that old 386 bios... I have played in them!!
Great video as always Peter!Keep up the good work
Thank you!
So cool. Around 1993 I bought very similar hard drive, but it was already mechanically destroyed, probably by a virus. I still have motors and damaged disc plate...
Virus can’t physically destroy a hard disk.
That's not virus activity. Sound like maybe the person responsible is dodging responsibility. "it wasn't me! Must have been a virus!" 😂
Some stepper and servo motor drives (yes, servo motor drives exist) are self-parking. Many Miniscribe ones will self-park after a period of inactivity. Many Seagate stepper motor drives will use the inertia of the platters to generate electricity to park the heads; I believe the ST-251 was the first to do this.
Nice job, I learnt something
Excellent work, you save that piece of computer history from the shreder!. i still have an old 286 motherboard with the same BIOS to do low level format. I recently bought an IBM Thinkpad 770X from a guy in Germany, the laptop is in very good shape but the original hard disk worked some time and started to slow down and showing bad sectors, i'm going to use the old board, maybe i can repair it?
Memories, thank you!
Great video!
Thank you!
Been decades since I had to low level format an RLL/MFM drive, I seem to remember you used to use the debug command to access something on the controller card?
I seem to recall the Dos command Debug and then g=c800:5 would initiate a low level format under various dos versions, Debug was quite a good tool back then.
That was back in the 286/86 days. Once you got to newer versions of Phoenix or AMI BIOS like this you could use the built in tools to do the work.
Very good job! Of what type is the mainboard you were using? Which manufacturer and board type? The bios based feature are very interesting!!!
Thanks for your very nice videos my fellow Retro friend, you have gained my subscription! I would love if you could dive deeper in the meaning of the CHS stuff (Landing Zone, WPcom...), I never know what those are or where to find the information on the drive...
Thank you very much! I appreciate your subscription a lot!
Good idea, I will try to cover your request in a video. 👍🏻
Cylinder, Head, Sector. On those older drives, those are usually printed on the label. If the label is gone/damaged you would be on a wild goose chase to find that now days. I just barely remember that stuff, because it became "automatic" about when I got into it. Only 2 reasons I remember is because I needed to know them when drives went over 512mb capacity, and I had a 386 with faulty CMOS battery wiring (wasnt a battery issue, bad board, eventually used AA batteries & didnt solve it). DISCLAIMER- I was a kid back then. They referred to "how many rings", "how many blocks per ring", and "how much data was in a 'block'". As I recall. I could be wrong, but I remember entering those numbers every day. Eventually got a 486, and after that, an "overdrive" cpu. One day I got a P3 "coppermine" and thought I was king of the world for a minute.
Very Very Nice repair. Can a 286 and 386 run 3.11 for work groups windows ? or Windows 95 ?
yeah, a 386 can run windows 3.11 and windows 95
@@CPUGalaxy though for windows 95 i think the correct term would be CRAWL not run
I would not want to run 95 on a 386.
I can remember running Windows 3 on a 286 with 1MB - it was a sample machine and only had the 1MB (640k plus BIOS shadow), and the rep that brought it said real mode wouldn't be great...
Standard mode, I said, and went into BIOS to swap the 384k from shadow to extended, which surprised him as he never knew it could do that ... many systems in that era could, but ONLY with 1MB - with more, the shadow cannot be reassigned
Ahh you didn't see what was on the hard drive before you formatted it!? Nice fix though.
your videos are awesome. may i ask where you are located?
I am from Austria 🇦🇹 😉
Hab schon auf Deine nette Email geantwortet ☺️ 🙏🏻
I have one of these drives faulty. It spins up, but it over speeds well past 3600 rpm and is not stabilizing. Would like it back since it was my fastest half height MFM drive.
Thanks for the video.
Can I also do that Bare PCB power-on test with my ST-225's PCB?
yes of course.
I have a Seagate ST-1100 with a very weird behaviour. If I terminate it correctly (no termination on that one, and one on another drive at the end of the cable), I can format with head 0 and that one only - it even boots from the drive like that.
When I change termination settings, I'm able to format with heads 2-7 apparently successfully, but not 0 and 1 - which makes the drive fail since track 0 is unavailable, of course.
Depending on how I install and terminate different drives, it gives a different result, so my conclusion is that it has something to do with improper termination for some reason.
Do you have any suggestions as to what might cause this behaviour?
Is that the normal size of a 386 board. It looks really big
It’s amazing how it can be in such a wonderful state of being a very old hard drive. Where can I get such old hard drives most of my childhood recalls. I also collect such old working capable hard drives. I have a Quantum Big Foot 5.25 inch hard drive. I would be very interested if you could get such old hard drives to Hungary by post relatively cheaply. Thanks in advance too.😊 Please more more such videos.😊
awesome channel! btw, anyone knows whats the music at 16:19? its the same as the outro in leonhart videos but i cant find it
Thank you. The music title you are searching for is: Exhale from Jeremy Blake. You can download it from the UA-cam Audio Library
Man i wish i could send you my MFM hard drive for repair. It doesn't spin up at all. I checked and checked nothing seems shorted and yet it doesn't start. The heads weren't stuck to the platters so it's wasn't that either i just don't know what to do. Tips?
makes me amaze how people used to manage in 42MB
easily back in the time. No internet, no mp3, no HD graphics, almost no graphics😂, no multitasking, simple GUI, games with 320x240 resolution, not 1000 threads hidden running behind your OS.... I know, younger generations might ask themself: what the hack were you doing with a computer back in the days... well, word processing and printing on endless paper with a 9 needle printer... playing prince of persia and programming assembler... 😉
Software was more efficient back then.
hola tengo un seagate st225 y una controladora LSD-6210 REV A3 pero el disco no me lo reconoce y cuando pongo el nombre debug y el comando se queda sin responer que no hace nada como pc uso un pentium iii desabilitado todas las controladoras internas de la placa pero nada y configurando los c-h-s en la bios pero nada podrias ayudarme
MayB a long time after this video, made me realise; how far Amiga & SCSI ws, back then. If they 2gether were appreciated more back then, the world would actually B totally... different. Maybee an apple 4 di... eye! Namasté.
What kind of drive is that at 11:50? Is that a Quantum? What is wrong with it?
I think the head was stuck so it wasnt moving and the coil took so much current it melted the cable Edit. Ok I was wrong, it was one of those famous tantalum caps
as I know for MFM drives you don't need to setup disk C: in the BIOS as for IDE. it doesn't require that at all
@CPU Galaxy
Hard disks has capacity - not memory if you talking about max. space on it... Memory is used when you want to say how much megs/gigs of RAM you want install or how much is already installed on the motherboard or how much for example cache CPU have...
clear. thx for teaching me. This are common mistakes done by not native english speakers. 😄.
@@CPUGalaxy
We all knew what you meant
Looking at how much is involved with these vintage components no wonder they cost so much back in the day.
They're not much cheaper now.
@@the_kombinator it looks like the cost of manufacturing would be higher but interesting if it is close.
Haha, deutscher?
Aber gute Videos, weiter so!🙋🏼♂️
haha, nein, ich bin kein Deutscher
would be more interesting to see what was on the drive
As said in the video, without the matching controller the data is unreadable. Disk and Controller build an Team which can't be separated or you loose the data.
r these desktop pata
Who else for no reason still remembers "g=c800:5" ?! Probably haven't needed to type that since about 1982. :)
Come to think of it, I think I still have a 10MB MFM drive somewhere.
lol, it turned out to have this command already in the ROM area of my brain 😂
i like ssd better they don't have to spin up
mit format c: /S hat man sofort bootfähig gemacht
Zuordnungseinheiten? Datentragerbezeichnung? I'm assuming that's german? I'm now happier than ever I didn't take german in school.
How I would repair it.. 🚮👌😂