MFM Disk Drive Repair, Low Level Format & Testing Tutorial  

Just so you know, Dave at EEVblog brought me here and now I'm binge watching all your videos. Fantastic content.

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.

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.

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

Great video, I love mfm hard drives. Fascinating stuff.

Thanks for a lot of great videos. I was brought here by Dave from EEVblog, one of the better chistmas gifts.

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.

You given me back my old memories! Thank you!

Great video as always Peter!Keep up the good work

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!!

Thank you for this detailed video I enjoyed every second. You got a new sub, and a new Greek fan :D

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.

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...

Memories, thank you!

Nice job, I learnt something

This brings back memories :o) I remember my first DOS computer, it had a HDD that was a MASSIVE 5Mb in size!

Great video!

Thanks for the video.

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?

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...

Ahh you didn't see what was on the hard drive before you formatted it!? Nice fix though.

Very good job! Of what type is the mainboard you were using? Which manufacturer and board type? The bios based feature are very interesting!!!

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?

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...

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.

makes me amaze how people used to manage in 42MB

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

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.

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.

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

Is that the normal size of a 386 board. It looks really big

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?

What kind of drive is that at 11:50? Is that a Quantum? What is wrong with it?

your videos are awesome. may i ask where you are located?

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?

Can I also do that Bare PCB power-on test with my ST-225's PCB?

Very Very Nice repair. Can a 286 and 386 run 3.11 for work groups windows ? or Windows 95 ?

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...

Who else for no reason still remembers "g=c800:5" ?! Probably haven't needed to type that since about 1982. :)

Looking at how much is involved with these vintage components no wonder they cost so much back in the day.

would be more interesting to see what was on the drive

mit format c: /S hat man sofort bootfähig gemacht

Haha, deutscher? Aber gute Videos, weiter so!🙋🏼‍♂️

i like ssd better they don't have to spin up

r these desktop pata

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.. 🚮👌😂