MFM drives are really unreliable

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#retro #mfm #seagate
Last week, we took a look at five MFM hard drives and controllers used to hook them up to a computer. In this week's video, let's try to get those drives working.
Part 1: • Not forgotten: MFM har...
Part 2: This video
--- Info
Drives in this video:
Seagate ST-225
Micropolis 1325
Computer Memories Inc. CM 3426
PTI - Peripheral Technology Inc.
Seagate ST-4051
--- Video Links
Seagate ST-225 Service Manual:
www.minuszerodegrees.net/manu...
MFM hard drive emulator:
• This thing can backup ...
IBM PC AT 5170 Series (talking all about BIOS patching):
Part 1: • IBM PC/AT Model 5170: ...
Part 2: • IBM PC/AT Model 5170: ...
Part 3: • Fixing and improving t...
IBM PC AT 5170 Patched BIOS for faster hard drives:
archive.org/download/ibm-5170...
SpeedStor:
www.minuszerodegrees.net/soft...
Spinrite II
winworldpc.com/product/spinri...
Mac 512k with a MFM drive inside:
• Macintosh 512K with an...
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10 фев 2023

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Комментарии : 645

@adriansdigitalbasement Год назад

Thanks to the resourcefulness of my viewers, I've been pointed to the service manual for the ST-225! I love this community. www.minuszerodegrees.net/manuals/Seagate/Seagate%20ST225%20-%20OEM%20Manual%20-%20Oct85.pdf

@evoelias6035 Год назад

Hey Adrian, thanks for the video; I was suspecting my hard drive to have scratches as well, so I followed your instruction to take the disks out in order to polish them - they do look fine now, after the polishing - but I forgot the right order to put them back in... does it even matter in which order I put them back in if I low format it? ...I'm obviously just kidding... 😂 great video mate! 😁👍

@llwellyncuhfwarthen Год назад

A lot of those drives even from that era may need to be actually 'PARKED' which could be a large cause of the not spinning up properly, or the heads not reading properly.

@timballam3675 Год назад

I have a few SCA SCSI drives and they make that sound quiet!

@evoelias6035 Год назад

@@llwellyncuhfwarthen this also explains the high number of broken drives from the era... people turned off their computers without prior parking the drive properly.

@afungusamungus2860 Год назад

Great content man, Thanks for the manual!

@nevellgreenough404 Год назад

Many years ago I was given an ST225 with bad sectors in the boot tracks. With nothing to loose, I opened the drive and moved the track 0 sensor inwards a little bit. Closed the drive, formatted it OK and used it for years!

@kd7cwg Год назад

I had a 40 mb ide with a stuck stepper motor. I took the top off, gave the heads a nudge and put back together. Never had a problem after 😳. My hvac class had a ps/2 that had bad sectors in the boot track as well. Just made a floppy boot disk, and all data and programs were accessible (including the games) 🤣

@stragulus Год назад

@@kd7cwg OMG yes I also had an old Conner drive that was pretty big for its time that I got at a computer market / hall with a bad sector 0. Booting from floppy then accessing it worked fine indeed! Man thinking about this I had so much old broken stuff I just bought from computer market junk piles for next to nothing that I got working through creative means. None of which I'd really rely on very hard, but eh it was good enough for hobby stuff. Also getting super cheap old SGI workstation monitors with weird connectors like 13W3 and getting them to work in linux by manually crafting X modelines until it gave a stable picture..20" CRT's that would heat your house for the price of a beer or two lol.

@edgeeffect Год назад

ST-225s are immortal.

@mikebarushok5361 Год назад

The main trick besides not breathing over or talking near the drive while the cover is off is to *always* put the cover on with the drive spinning.

@IlBiggo Год назад

@@kd7cwg The system disk of my first digital recording studio's Atari refused to start one day, so I opened it up, gave a little spin to the platters and it restarted like nothing had happened. For the following few years the morning routine was open the drive, turn everything on, help the drive spin, put the cover back and just pretend it was normal :D

@Runco990 Год назад

I remember trading a motorcycle for a 600mb Micropolis drive. It was an absolute beast! My whole computer shook back and forth when it accessed the platters! That was baller storage at the time! And yeah, they were all loud. Fluid dynamic bearings were a game changer.

@KenjiUmino Год назад

I bet that 600mb hard drive had more cylinders than your motorcycle ;) ... but I also bet the motorcycle was able to make a lot more noise than that harddrive - no matter how loud it was

@petevenuti7355 Год назад

I used to have a bunch of those under my desk. When I turned on my computer it reminded me of a big rendition of the tune to that song "My Sharona" as all the drives initiated. Or should I say took off.

@ricardog2165 Год назад

You should save the logic boards from the dead drives, so that if you see the same models in the future, you can swap them to see if that fixes any problem. At the very least there might some valuable parts you can reuse.

@jeromethiel4323 Год назад

At a place i used to work, we had some old S-100 buss computers that had hard drives (yes i know, it's weird). And these hard drives would get to where they would not spin up. We had to remove the drive, remove the cover over the platters, spin them by hand, then re-assemble. These drives lived through that so many times it isn't funny. For at least 6 years we kept having to manually spin those drives, and they never died or lost data. Which is just amazing, considering the head clearance on a HDD.

@competetodefeat4610 Год назад

Hard drive: It has been so long since I have been given a voice... allow me to sing you the song of my people.

@RussKnize Год назад

It was nice to hear those old Seagate drive sounds again. Growing up, our computers were made almost entirely of broken parts. The only reason we had hard drives at all was because they had died for someone else (mostly at my dad's work). For the most part, the old Seagates could be brought back with a low level format. Stiction was a thing, and we got in the habit of rotating the entire PC case while flipping the switch. They would occasionally get flakey again, but we kept backups. Later, Spinrite became a thing and it brought back those drives in-place, data and all. That tool was a godsend. We also had a 600MB Micropolis SCSI drive at one point that took so long to spin up that the controller would timeout. It was very loud, but was very reliable. Ah memories...

@ppokorny99 Год назад

Upvote for the spin rite reference. That was an awesome tool

@marzsit9833 Год назад

i saved many 'dead' drives using spinrite. stiction was definitely a thing with seagate st-225's made during a 4-6 month period, i have 2 st-225's in my 10mhz xt clone. the boot drive always starts up, the second one always sticks if it sits for more than a week. i was told that the stiction problem was due to the heads being too-well lapped and smooth, which causes them to stick to the platters. if the drive doesn't stick, it's because the heads are rough. go figure...

@LewinEdwards Год назад

With the ST225, try pulling the PCBA off it and cleaning the contacts that connect the HDA to the PCBA. If I recall correctly there will be spring connectors for the hub motor and an elastomeric connector for the heads. Worth pulling the elastomer out, cleaning with IPA, and flipping it so the "squished for 30 years" parts are no longer aligned and it makes slightly tighter contact.

@spamviking8591 Год назад

Seagate and “most likely to work” two things I never thought I’d hear together.

@maxtornogood Год назад

You know it's gonna be good when Adrian has to drop regular noise warnings in!

@kingforaday8725 Год назад

Brings back memories of what a PIA setting up a hard drive could be!

@KAPTKipper Год назад

Indeed, heads, cylinders and sectors was a PITA. Varied from BIOS to BIOS

@danman32 Год назад

ruined the data on 0 track on someone one time thinking the settings on the PC was wrong and wasn't utilizing the whole drive. Turned out back then the CHS on the BIOS was skewed to what the HD/controller expected. Believe it or not, I was able to recover almost all of what was on the drive. How you ask? Folders are actually files, almost all subfolders and files were in folder, and almost everything on the drive was one cluster or contiguous clusters. Using tools that could read the drive raw, searched for sectors containing '.' and '..'. Those would be folder entries. Get the size of the folder, calculate the # of clusters, and slowly made a map of what the cluster table/File Allocation Table (FAT) should be. Get the file entries in the folder entries and repeat. I only had a handful of situations where if I assumed contiguous clusters, I ended up with file chains that would appear to have cluster collisions. Analyzed the data in the sectors assumed to belong to the files, and I could figure out where the next cluster actually was an for which file. But when you only have a few 10's of MB, you could do that. Forget trying that with GB or TB!

@jorgepinogarciadelasbayonas Год назад

The Commodore A590 was the first 20 MB hard drive in 1989 for the Amiga 500 (Autoboot did only work if the Amiga used Kickstart v1.3) and i believe it used one of these MFM drives which was a Western Digital XT model (you will find pictures at Google because those XT drives are fairly big). The A590 was having a XT and SCSI interface. The read and write noises are funny and very mechanical. If a floopy disk was in the disk drive the Amiga did autoboot from the disk drive otherwise the hard drive took over. Amiga was having a very clever auto config system just like modern PCI from the PC.

@volvo09 Год назад

Ah, the ST 251 was the drive I remember having.... 40MB and I remember the sound of it self parking when turning off the computer.

@Quickened1 Год назад

Something I always used to do when testing hard drives, is I would always write the date when I wrote notes on the drive. Makes it easier on you in the future! Let's not forget, when you open these babies up, be sure to grab the neodymiums... Free magnets are always great. Fun stuff...

@monad_tcp Год назад

those don't use voice coils, watch the previous video

@ThePuuFa Год назад

I remember when I was a child in the late 90's we were given a free Philips 8088 PC that had a rather peculiar start up procedure. You'd have to heat up the hard drive with a hair dryer or it would not spin up at all, but once you got it hot enough it would run perfectly fine. We used to play a ton of old games on it for a year or two and it was still working just the same when I gave it to a friend of mine some time in mid to late 2000's

@80sCompaqPC Год назад

Sad to see none of those drives worked. Was fun to see the insides of them though! I’ve actually had incredibly good luck with MFM drives, and most of them I’ve gotten have worked fine with little effort. I actually just tested all of my spares recently and they all still work fine. Some of them I’ve had for years too. I will go to great lengths to repair them sometimes as well. For example, I did a spindle motor replacement on a Miniscribe recently, which was 100% successful! Obviously, I’ve definitely gotten some bad ones over the years though, but I’d say probably 80 percent or more of them I’ve bought worked fine in the end!

@chriscottingham9088 Год назад

The useless old stuff in my mind.. debug g=c800:5.. The good old days! Thanks for the great content Adrian. Keep it up!!

@andrewdonatelli6953 Год назад

I came to make the same comment. LOL

@paulstubbs7678 Год назад

Now that triggers a memory in me.

@marzsit9833 Год назад

DTC 5150

@CaptainSouthbird Год назад

Ah yes, to trigger the hard drive controller's ROM utilities... I was born in 1983, which makes me effectively a "90s kid"... my first computer (386SX 25MHz) was already using IDE for the hard drive and at least the beginnings of BIOSes as we understand them today. I missed out on the MFM era of storage, although thrift stores started dumping 5150s / XTs / 286s / etc. en masse somewhere in the later 90s / early 00s. (For cheap! Imagine getting a fully intact IBM XT off the shelf for $5!) Although I bought a lot of then-"old" hard drive controllers and MFM hard drives, I assumed they were all "bad" because they just reported error codes. I wish back then I had known about triggering hard drive controllers internal low-level formatting utilities as such (and how critical that was!), but I wouldn't figure that out until somewhere in my late 20s when I started messing with this stuff again and of course the Internet was more prevalent with such information. I've made a couple ST-225s work since then in proper 8088 based PCs.

@rdh2059 Год назад

Back in the day, Micropolis Hard Drives were mostly large, high volume disk drives. They were known for being noisy, but were usually larger (storage space wise as well as physically) than other drives. Seagate MFM drives were some of the most reliable back in the 80's. They were also the largest producer of MFM drives at the time. Miniscribe were primarily hard drives used in business. Western Digital had a few, but no one could compete with Seagate. Things changed when IDE took over. Western Digital and Maxtor took over the top 2 spots.

@MrZorbatron Год назад

You ever hear the miniscribe brick story?

@rdh2059 Год назад

@@MrZorbatron are you referring to the fraud stuff they were involved in, to attempt to keep stock price from falling?

@MrZorbatron Год назад

@@rdh2059 Exactly. If I remember correctly, they shipped cartons with pieces of masonry that approximated the weight of the drives that should have been in them, ostensibly with the intention of recalling the items in short order, before they would have made it into the distribution channel. Unfortunately, things didn't go this way and it was caught. I might (probably) be missing something because this is something I learned about probably 15 years ago. I understanding was that the books were cooked well worse than was initially apparent.

@negativesaucer Год назад

this certainly was a blast from the past. I recall servicing drives suffering from "sticktion" or however you'd spell it. we called it that as well and the root cause I was given was that the spindle lubricant would cool and harden beyond the initial torque point of the spindle motor. as crazy as it sounds, the fix that worked most consistently for us was to actually drop the drive flat onto a table from a few inches up. well within the engineering g-force tolerances but enough of a bump to knock the spindle loose and boot the system for imaging.

@julianbrown1331 Год назад

Not sure I agree with the heads stuck to platters description of sticktion... much more likely the bearings are "seized" up, too much drag to get spinning. If the heads were stuck the damage would be terminal

@docnele Год назад

Agree. Bearings are the main culprit, because the lubricant in them becomes old and sticky, just like in wristwatches. Sometimes push start helps and lubricant softens a bit (for some time), but sometimes it doesn't and motor cannot reach required speed (or reach it before the timeout). I had a similar problem with laser printer (spinning mirror spindle) and had to put some hair-cutter(!) machine lubricant, as it had the closest viscosity and lubricity to whatever stuff was there before.

@Pickelhaube808 Год назад

It would make sense if the read/write head and the platter were made of the exact same material, which could lead to a sort of cold welding such as with gauge blocks. However, the bearings make much more sense.

@nickwallette6201 Год назад

That has never made sense to me either. Either it wouldn’t take much to break the joint, and so it shouldn’t ever fail to spin, or it would rip the fragile heads right off, and that would be the end of that.

@ericpaul4575 Год назад

Also the grease can be fine when the drive is up to temperature but as soon as you turn it off and it cools down the grease gets hard and the drive will not spin up.

@scotty3114 Год назад

At the time, the official explanation was thus version of sticktion. The head and disk being so flat that they would create a high amount of drag. Even brand new drive could display this problem, once spun up, they woeld work for years.

@justinchampion5468 Год назад

Thanks for the fun MFM video! - Also, I love the half-smirk you got right while holding the screwdriver menacingly saying 'percussive maintenance!'

@therealchayd Год назад

It was great hearing the sounds of those old drives, brings back memories. I still have my original SCSI version of the ST-225 (the ST-225N), would be great to spin it up and dig through all the old '80s software and long forgotten programming efforts.

@radio-ged4626 Год назад

I used to rebuild those ST225 drives. They have a track 0 - 1 track and I think another track (or cylinder if you like) beyond the last cylinder 612 with a data pattern on it. After replacing the platter and cleaning/inspecting the heads we would then write the track -1 pattern with a very home-made box connected to the ST506 connectors it would step the head stepper motor back (on which we drew a dot on the spindle) each time you pressed a button then you pressed the write button I think there was another button to get to the other track or there was some combination of presses. The drive would then come ready. We then did a surface analysis with a dedicated Winchester testing and diagnosing machine which would mark any bad sectors. Then we would attach it to a PC with a controller and do the debug g=c800:5 to low level format the drive and then we would partition and do a high level format. When rebuilding the drives we used little plastic spacers to separate the heads for removing from the platters, we inserted the plastic spacers with tweezers, really fiddly. All this while wearing a paper suite, gloves and a mask while a blower in the clean room tried to blow everything away! I bet all that kit went to the scrap yard years ago. For stiction we used to gently flick the heads (off the media) with the plastic spacers, which would demagnetize them and usually this would get rid of the stiction.

@JulienMR 6 месяцев назад

Hi, I have an ST225 which is only capable of showing its catalogue, when I access it through a floppy boot disc... ever had this symptom? What would be your recommended approach? Cheers!

@radio-ged4626 6 месяцев назад

@@JulienMR HI. Are you interested in recovering the data or do you just want to get it going? I would ensure you have the correct cyls/heads set up and also that you can read other drives with the method you are using first before attempting anything else. My guess is you're able to read the contents tables and the data isn't visible because the heads/cyls are set wrong. Should be 615 cyls and 4 heads which I think is the old IBM type 2 size 20MB (21MB formatted 26MB unformatted) If my memory serves me right. If you have no luck with that try formatting with DOS. If that doesn;t work then a low level format using debug could be needed prior to the DOS format. Run debug from DOS using the command line: debug g=c800:5 from the HDD ST506 based controller card ROM if that works when complete run the DOS format again. Obvs this will destroy any data on the drive but will make it usable in DOS again if the board, heads and platter are OK. As it seems to be coming ready and you can read the directory I assume at least the hardware is working. Good luck. BTW this is only my opinion I haven't seen an ST225 for over 40 years so I may have forgotten a few things. So do this at your own risk.🙂

@radio-ged4626 6 месяцев назад

Oh - if you low level format you will need to create a partition before the DOS format using FDISK I think.

@JulienMR 6 месяцев назад

@@radio-ged4626 Thanks ! I'm pretty sure than the HDD Type is good, as I checked the switches on the controler board : Off/On/Off/Off, and the first two being Off/On means Type 2 for Drive 0 (the next 2 values are for Drive 1, and I don't have any). I didn't try any Format command yet as I hope to save the drive content, but I'm thinking more and more about it !

@radio-ged4626 6 месяцев назад

@@JulienMR Yes, it could be the drive was set differently on a previous controller so that's why you can't read the content.

@iamimiPod Год назад

I'm glad you made a video showing how often they just can't be fixed. I've got one that doesn't work and I was trying to work out why I couldn't fix it as easy as some of the other videos that i had seen.

@NEEC1 Год назад

Enjoyed seeing inside the drive while it was spinning and moving the head. Fun stuff!

@stonent Год назад

I always kept a computer around back in the day with AMI BIOS and ran the AMI Diag utilities on the hard drives. It was an excellent way to get drives going and even I think in some versions did speed tests to determine your ideal interleave number.

@iteachtime Год назад

Your videos are never a bust! Learn so much. Thank you again.

@retrozmachine1189 Год назад

I had a similar model Micropolis HDD to that one and it was quite loud too. Seeing the motor PCB bought back memories. Compared to the original ball bearing based Seagate 3.5" 7200 RPM Barracuda hard disks the Micropolis was quiet. Those things were really loud. They were so loud that it was uncomfortable to be nearby. They ran roastingly hot too. It really makes you appreciate the later FBD designs.

@davida1hiwaaynet Год назад

Thanks for this video! I remember the sound of the old ST-225 and similar drives. The good old days! You put forth a great effort on these. Much appreciated. This reminds me of the efforts we make to un-stick antique refrigerant compressors which have become stuck from dried up oil or other problems. The only difference is that we use 240 or even 480 volts of raw power to get them broken free. Thankfully, opening them up doesn't equal death with these devices!

@burntoutelectronics Год назад

Yes, unless you burn out the windings, an old compressor is probably a lot hardier than a delicate hard drive of this vintage

@ProdigalPorcupine Год назад

I love your channel, Adrian, thanks so much for your hard work. I've opened up quite a few non-working old drives where stiction had been 'fixed', by force or by itself, to find the heads still stuck to the platters, ripped clean off their mounts. The noise it made when the drive was running was unmistakable. Happy days! 😂

@adriansdigitalbasement Год назад

Haha yeah that's happened to me too. Slamming into the now naked arms as the drive spins up. Bad times indeed!

@Bruces-Eclectic-World Год назад

When I worked at a computer store in the late 90's we would put the drives in a fridge when they had sticksion overnight and if they would spin the next day we got the data off of them with Laplink and a Laplink cable. Good times to be sure! We called it "Shake and Role", 1st you shake the drive side to side, 2nd you would shake and role it in a circle that the same time and if that did now work them it was Thump time with a screwdriver... Lol We used HardDisk TecSpect v6 to get 99% of the drives specs we worked on back then. I believe it cost $100.00 US for a 2 licenses copy back then. Great video Adrian! LLAP 🖖

@thesmokingcap Год назад

Love these sorts of videos, it's just good old fashioned fun! just messing around with some old hardware

@Lirchicus Год назад

Stiction was also an issue in large CDC sealed drives. We discovered that if the heads didn't move, the Teflon surface of the platter would get hot and effectively become an adhesive so when the heads landed, it would effectively "glue" the heads to the disk surface. What we finally ended up doing was modify the HD driver to rapidly move the heads around any time we went some number of minutes (I forget the actual time) without being accessed. We would that move the heads to a random sector.

@Hellhound604 11 месяцев назад

Your video brings back memories of the good(???) old days building/fixing/optimizing PC’s. Have forgotten how much an issue those old MFM/RLL disk drives had, esp. when larger drives came out that were not directly supported by the BIOS. Good walk down memory lanes. Thanks

@mikebrowning1624 Год назад

I really enjoyed hearing those spinup sounds. Very nostalgic.

@TvistoProPro Год назад

I had a ST-225 WAY back in the day. I'll note that those often get SUPER hot, which is part of what causes "sticktion". Even the best of them got hot enough to effectively melt and then boil away any lubricant used. I had one that after running for a day or two solid got hot enough to literally to unsolder it's own components. Seagate's answer to this was to always mount it with the metal body pressed against the cage to act as a massive heatsink. Always good to see older technology of yester-year. Also, most of the ST-225 were from the age where you could use MFM or RLL. Given then RLL would make the same drive about 38M (vs 23M), I'd bet the one you had was formatted as RLL.

@tdaonp Год назад

This brings back so many memories! A fun watch. Thanks!

@Mr.OCanada Год назад

This is exactly what I played with in my bedroom when I was supposed to be sleeping and get to school the next day. I want to think... Early 90's. And as I posted before I ended up running a BBS off these things. I have a lot of current coworkers who went to University and "learned" I.T., and they would have no idea what these things are. I feel I just walked into this career and back then I would thank the stars any tech I could get my hands on in the day.

@tomswoodwork Год назад

I had a BBS back in the early 90's running Wildcat! BBS. I had a 286/20 for my BBS computer and a 486SLC/40 for my personal system. I had a Seagate st225 in the 286 and a 80 meg WD and a 200 meg WD drives in the 486. I ran Lantastic Z with a parallel cable between them and then later upgraded to NE2000 with Novell. I had all the BBS data on the 200 meg drive and a tape backup that ran every night to back up the user data. When he fired up that st225, I knew EXACTLY how it was going to sound and when I heard the heads move, i knew there would be a "ding" to let you know it was ready. Sucker sounded like a jet engine firing up.

@CutieHoney Год назад

I had a Micropolis 1.2 G on my Amiga back in the '90s. One day I came home from work and I could hear it squealing before I got to the front door. Fortunately I was able to get all the data off of it by wearing tight headphones.

@stevethepocket Год назад

Wait... if it was running before you got home, who was using it? And HOW???

@CutieHoney Год назад

I never turn off my computers.

@1DR31N Год назад

I enjoyed your video up to the last minute. I remember other HDU technology, called RLL or Run Lenght Limited, even more unreliably than MFM. Great video.

@kellyherald1390 Год назад

Those old drives that had voice coils for the head movement have excellent magnets. I've got a couple of voice coil magnets from an old Micropolis 9GB SCSI drive and those magnets are super strong.

@leoparadis8036 Год назад

Thanks Adrian. I spent the last 30 years working at an industrial site that used the micropolis RD53/54 hard drives with microvax 2 mini computers running a propriety software. They were all MFM drives and used Dec M7555 controllers. We had up to 13 running in the field and at least 3 backups running in our maintenance shop. As well we would sends them out for repair at W.M. Farris in California. There were a number that would scream during startup and then get quieter after running for a few hours. Just before I retired I replaced them with solid state MFM drives made by DREM. The DREM drives worked great. Thanks for the memories...

@aaron71 Год назад

I have had a lot of those ST-225 and don't think I've ever seen one with the SEAGATE logo on the bezel! Neat. As for the loud drives I've had luck just letting them spin for an hour to loosen up the old lubricants. Plus I just love listening to them 😄

@ujohn19 Год назад

Those Seagate ST-225 drives where bullet proof... and I mean they would stop actual bullets. In the mid 90's I took one out in the woods when we went target shooting. A .45 puts a big dent in it but did not penetrate. A 9mm put a little dent in it.

@andrewdonatelli6953 Год назад

I worked as a technician in the late '80s through mid-90s and we called it stiction too. I would lift the anti-static strap underneath and twist the spindle with a pair of needle nose pliers to get it started and then immediately back up the drive.

@Halterung01 Год назад

I don't know how to thank you for showing the jumpers on that ST-225. I've had a 225 laying around thought to be dead for years now but it was just set to the wrong drive select, the thing actually works, I am ecstatic right now. Thank you so much for your video.

@theposguy1435 Год назад

I live in maryland and there was a rock station out of DC and up to maybe 10 years ago they had some old computer running in the studio using a Seagate st-225 maybe ... just funny driving to work and I could hear that drive running in 20teens Thanks for the video!

@Bergi2000 Год назад

Hello Adrian I enjoyed this video very much. 😊 My first pc at age 16 had a ST-225 and i also had that PTI Drive in my Fingers. :) Moving inwards track 0 and sticktion… memories :) Thank you!

@PaoloMarcelli Год назад

I would love to see more videos about testing and trying to fix old HDDs

@nikfs5620 Год назад

Tbh the best part was seeing you have fun taking those drives apart haha!

@DataWaveTaGo Год назад

MFM drives could be interesting to repair. In one case I had a 15 Mbyte drive (3 X 5Mbye platters) which had a head crash on the top platter. I removed the bad platter and made it a 10 Mbyte drive, which worked for many years.

@8088argentina Год назад

Yo hago lo mismo cuando el cabezal está dañado, le reduce la capacidad pero funciona, hice algunos videos

@davidbwa Год назад

wow. this really took me back to my early tech days. the sounds, the slow spin up, parking the drives, termination jumpers, 'thumping' a stuck drive, the really slow error checking etc Reminds me of many things I don't miss about older PCs. I forget what model of HD I got it out of but I had a head arm (desk toy leftover part) that looked like you could drive a vehicle over it. The old drives had so much more metal in them.

@stevewhitcher6719 Год назад

I remember them not being very reliable back in the day. I got my first pc a clone 286 because the mfm hard drive died and it was thrown out. I also remember that even later with some 386 clones that used ide that the bios was limited to specific drive geometries i used to get these very cheaply without the hard drives (not sure if they had broken or the drives were removed for security) there was a work round on these which i think was some sort of drive geometry translation utility, but i cant remember how it worked or what it was.

@danman32 Год назад

I had a seagate 20MB HD, probably the 225, that stopped working. So went out and bought another one. I think I paid $400 in '86 or so. I too had the idea to swap the boards on the HD. BOTH WORKED! So then I had 40MB of storage. Whoo Hooo!

@agw5425 Месяц назад

Whether the hardware works or not it is never a failure when you learn something useful, I call this a success with a twist.

@Ruddy761 Год назад

Thank you for the trip down memory lane! (there's a pun in there somewhere). I still have a couple of these drives but no mfm controller. I still have my very first hard drive I used on my ColorComputer. It's a 5 meg - yes 5 meg shugart full height drive. It still spins up and self tests.. Now you make me want to find a controller! Thanks!

@retrozmachine1189 Год назад

precomp, precompensation, is a slight timing alteration during writes to inner tracks to account for the higher flux density on those tracks causing problems with adjacent transitions. The same thing is seen on floppy discs too.

@DarkVain Год назад

I remember all those drives. The st225's always had problems, but could always swap the boards to get working drives out of batches of drives I would pick up. Still remember the days of nothing but noisy drives. My ears are still bleeding to this day from using whatever came in the door to give more storage space. Gone are the noisy, but fun days.

@exidy-yt Год назад

I owned a stepper-band driven SCSI hard drive for my Amiga 500. Yes they WERE that loud. I could hear it 2 rooms away, both the roaring of the fan/spindle and the chittering like a typewriter of the heads over the platters. They were bloody LOUD, Adrian. 🤢

@RonHelton Год назад

I love these old drives. The good ole days. I still have a few around here somewhere in my piles. We thought we were "going to town" when we got the ST-225 hard drives. LOL

@FlyMIfYouGotM Год назад

Even more fun to get an ESC for RC aircraft and use it to drive the spindle motor with the platters still attached. You can spin these things crazy fast with the right ESC. Probably something you should do in an area where exploding platters won't damage anything or kill anyone though. Fun times!

@chadhartsees Год назад

I'm surprised this isn't a "II" video, but I'M HERE FOR IT. This episode borders on ASMR. Perhaps clip some out for shorts! LOL @ the QC Pass sticker.

@WackyT08 Год назад

While working up at Seagate on contract got the opportunity to see them spin testing a large glass platter. That thing went off like a bullet! Forget what RPM they got it up to.

@scsirob Год назад

The fastest 3 1/2" drives were 15krpm. I believe I read somewhere that every attempt to go beyond 18krpm on commercial scale failed spectacularly. Also happened withCD/DVD drives that were 52x. A tiny imperfection of the disc was all it would take to shatter,

@mnotgninnep Год назад

Thank you for this. It was really informative. The main thing I got from it is I have been really darned lucky, getting 3/3 working drives.

@emolatur Год назад

The ST-225 schematic is in the back of the ST-225 oem manual. Every time I post a link on RU-vid, RU-vid deletes my comment, but "minus zero degrees" has it.

@retrohaxblog Год назад

Excellent video as usual Adrian!

@rieger.design Год назад

Great video! I got once a bunch of old drives and turned their plates into fancy coasters

@pantera2867 Год назад

Hello Ardrian . Fro ST-225 - Faulty track 0 signal ? all the time trying to calibrate , try to make that trick : -normaly connect the disk , don't setup disk in the bios . Run MS-DOS after that run program SGATFMT4 from the list chose geometry (CUSTOM = 615 ,4, 17 or "ST-225") , after that Option 1 Low level (blind formatt without verify).Turn off the pc and turn on setup in the bios reset if pass calibration it's ok if not change the PCB and do the same .Common problems : -Head crash ,faulty IC , PCB read/write error because of age .

@dhpbear2 Год назад

3:00 - Way back in the day (1988) I had a couple of half-height 5-inch drives that made that sound! They worked! It was a frighting sound where two frequencies were beating against each other. The noise was more aggravating than anything else.

@Drucklufttroete Год назад

That Micropolis drive is specified for 33 256-byte sectors per track. On a PC, sectors are 512 bytes, so that's why the capacity didn't match.

@stevenretroworkshop2113 Год назад

I have a Zenith Z-248 computer. It has a Control Data Company 10 meg. byte hard drive installed. It a full size 5.25 hard drive. I still use to play vintage computer games on the machine. I really enjoyed hearing those spinup sounds. Very nostalgic.

@ultrametric9317 Год назад

I remember some Winchester drives in a PDP-11 that sounded like a lot of loose change in the dryer when they spun up, but they worked fine! Compared to voice coil drives they are pretty robust.

@scsirob Год назад

Those were 14" RL01/RL02 possibly? I know there were some with 5MB fixed disk and a 5MB removable disk pack. These things were *loud* ..

@stan.rarick8556 Год назад

Not a bust - second half interesting and informative for those who haven't seen the inside before. Brings back memories from 20-30 years ago.

@JohnnyBareToes1 Год назад

Very interesting video. I recently had a hdd go bad and I let my young son take it apart. He was fascinated by it. Things didn't go so smooth when I asked him to put it back together lol

@juliefugett2426 Год назад

This video was not a bust-it was hilarious. Thanks for sacrificing all those cilia for us!

@TechTimeTraveller Год назад

Also at roughly 17:00 .. I had a weird one where a miniscribe mfm I had did what you had there.. wasn't initing properly. I could see the stepper motor moving so I assumed drive electronics. Then I exercised the stepper and felt it was a bit stiff.. used your video on lubricating those as a guide.. voila.. it worked. It had enough function to move the stepper convincingly, but not enough to move it all the way to the extremes for initialization I guess.

@solarbirdyz Год назад

We had one of those ST-255s that would get stiction. We'd flip the drive over, lift the static arm off the axis, torque it back and forth a little with needlenose pliers and it would work fine for another few months.

@rrho6701 Год назад

Take the platters, drill a small hole near the edge. Take one of them and drill evenly spaced holes around it's edge. Suspend the single hole platters from the multi-hole one with light fishing line. suspend the whole contraption by fishing line strands attached to the multi-hole disk, and tied together. This gives you a great sounding wind chime. You can even drop one through the center with some salvaged polyamid cable to catch the wind & act as a clapper.

@ForgottenMachines Год назад

38:00 Oh, contrare, Dear Adrian, this is a MOST Excellent instructional video!

@EShirako Год назад

Yeah, ST225's did have stiction, and my shop called it that too. So, my solution was to set it on a desk and swatting it gently on one corner of the front of the drive (Say, just by the "WARNING" label) with a plastic hammer or small rubber mallet. Contrarily, I always suggested replacement, but once I swatted a drive free like that, at least MY limited experiences (6 or so drives?) had none come back having utterly failed in the time I was working there. Another possibility is that the ST-225's also had a 'transit-parking option' that needed an actual 'unlock-park' program tool to tell it to release the heads and spin up the drive again. I think the first version of SpinRite had had an option to Park Heads that could activate that mode...but it's been so long that I can't remember for sure. I had tools to allow parking and unparking. Some drives did nothing until un-parked, while most would spin up but not release the heads without the un-park command-or-whatever. I think Maxtors (EIDE and SCSI) would spin but need to be un-parked to fully come online. Also, the drive previous (ST4051?) sounds like it has a crashed head. One of the heads is no longer 'floating' like it should be, so it's dragging. At top speed it was at least almost-floating, but that was a seriously-terrible sound, and I would not expect the drive to live for long, IF it hasn't already flipped the head over. I write this 5 minutes in, so we'll see what it shows later when he takes it apart! :) The CM drive didn't sound bad, but it didn't 'click' and unlock the heads so it may have an issue...or may need to be un-parked, but if the rotation never mostly-stabilized, there may well be an issue. The Micropolis 1325 doesn't sound awful. Some drives can be REALLY DARN LOUD. Maxtors and Fujitsu still come to mind. @.o Oh the noise. I had a SCSI setup and powering on took like 4-5 minutes and sounded like I thought 'powering up a nuclear reactor' would be kinda like. Noise is no guarantee of dysfunction.

@Kali_Krause Год назад

Have you seen a Fujitsu M2243AS? That thing is loud due it having a whopping 11 heads! It's also a voice coil drive according to the specifications :)

@JacGoudsmit Год назад

In the 1990s there would be computer fairs in my country (the Netherlands) a few times a year and because I didn't have a lot of money, I was on the lookout for used MFM hard disks. My PC didn't have IDE, only MFM (later RLL) and I also built an interface for MFM drives for my Amiga 500. Unfortunately, I learned the hard way that a used drive may not be a working drive, and had to throw a few drives away, after I had walked around with them all day and taken them home on the train. It often happened that some stupid user had accidentally low level formatted the servo surface which would would make them permanently unusable instantly. In the end, I took a 12V sealed lead-acid battery with me, and a connector that had an LED on the READY line (which I think is right at the end of the connector), so I could rummage through boxes of hard drives and make sure they at least reported as ready after speeding up, so that I wouldn't have to waste money anymore.

@jhfgjtjutyiuod Год назад

Even fairly modern hard drives could be loud back in the day. I remember when I bought my Amiga 1200 brand new in 1992 with an included 40mb HDD I was amazed how loud the tiny little 2.5" HDD was in it. Turned out Commodore in typical fashion bought up the cheapest nastiest drives they could get their hands on for the job. The HDD in mine was A Conner unit I believe.

@JCWise-sf9ww Год назад

Thank you for a walk down memory lane on MFM HDs. I have a lot of various old MFM drives, ST-225s and a 5 meg Sea Gate drive with a damage disk from my own doings otherwise it could be a working antique HD.

@bobblum5973 Год назад

Here's something I came across on Digital Equipment Corp. VAXstations and microVAX minicomputers from the mid-80s using these types of drives: loud, high-pitched squealing. We thought the drives were failing, but it turned out there was a small hard graphite cylinder held onto the end of the platter spindle by a brass colored clip. After months or years of continuous operation, the end of the spindle shaft would polish a dimple into the graphite, which would squeal or shreik as it spun. We learned we could loosen the screw holding it on, and either shift it slightly or remove it entirely. Noise gone! The graphite "button" appeared to be there to bleed off static charge from the spindle and platters, so we typically just readjusted it. Only 22 minutes in, but wanted to post this before I forgot to do it afterwards.

@AltoidJTP Год назад

I seem to remember some drives had a small hold on the bottom side where you would nudge a flywheel. The fault was rare where you would need to use that, because it only happened when the drive spindle happened to come to a rest at a "dead spot" between the coils.

@MCPicoli Год назад

A few even had black and white lines for usage with a stroboscopic light for fine speed adjustment.

@foxyloon Год назад

I have an old Televideo 286 machine that has an ST-225 installed in it currently. I've made several attempts in the past to get the drive working, so I'm hopeful that I can apply what I learned from this video and give it another shot. What's unusual about this machine is the floppy and MFM controller cards are integrated into a single card that was designed in-house by Televideo. The floppy controller part of the card works just fine, but the MFM controller portion seems to be completely dead. Although the chipset appears to be a common WD Winchester controller, I could not get Speedstor to recognize the controller at all, no matter what machine I had the card installed into. Either the card is so unusual that it's not compatible with my 486/Pentium machines, or more likely there's a fault with the controller itself. Perhaps the drive itself is dead, but I'm not certain because I don't have another drive or controller handy to properly rule out what's causing the problem. Before someone asks, yes I'm the OP from that Vogons thread about said Televideo 286 machine. I made quite the blunder and decided to split open the drive to inspect the platters. Let's just say the other members in that thread weren't too happy about that. In short, I've since been on my own trying to figure this out. >.>

@tuworlds 11 месяцев назад

i love what you do. i had to subscribe

@brianlhughes Год назад

My 1st IT job was programming on a Honeywell mainframe. Fixed and removable hard drives, the platters were huge 16" diameter or so. Head crashes on those things left a deep gouge in the metal, catastrophic damage. Heard a story where the heads crashed through the side of the case. One time the OS reported the loss of a removable drive, some maintenance guy had unplugged it so he could plug in his hand drill. An Entire room at the facility was built and designed just to house mag tape library. Yeah those were the bad old days. I read somewhere that it would take a mainframe billions of years of computing to equal a week of the computational power of a modern smartphone, all that electricity too.

@scsirob Год назад

My first drive was a Rodime full-height 5 1/4" drive hooked up to a CP/M system. This gave a whopping 4MB capacity. It couldn't boot from the harddisk, it needed an 8" floppy to run from. The disk controller actually didn't know how to seek beyond track 255. I reverse engineered the CP/M BIOS and got it to double the number of tracks, so I could do 8MB on a later Vertex drive of some type. Had plenty of fun with Micropolis stepper motors going bad, Maxtor XT2190 sticking etc.

@dashorken Год назад

I would love to see some repair attempts here if the issue is non-mechanical. Anyway, next video idea: QIC tape drives such as the old Colorado QIC-40, etc!

@mistermac56 Год назад

Micropolis drives were notorious for running extremely hot and failing fairly quickly. I remember back in the day we were backing up one of our server's Micropolis drive RAID arrays to tape so that we could restore the contents to a new WD RAID array, and it took forever. The drives were getting extremely hot, even with a fan in the RAID array case. So we took the cover off the RAID array enclosure and stuck a box fan in front of it to keep it cool. Once we had the data restored to the new RAID array, and making sure everything was working properly, we sledgehammered the Micropolis drives and sent them and the old RAID array case to recycling.

@JohnC5 Год назад

a fun video, thanks, some HD sounds are almost like from a horror movie 😅😱

@GilgaFrank 2 месяца назад

The word "interleave" sends a shiver down the spine of anyone who has ever tried to set it optimally.

@ofbarea Год назад

Back in the day installed these drives with an RLL card. That increased the sectors per track and usually usually after a low level format, and scan for bad sectors, all were functional. Then used Norton Disk Doctor to calulate the interlive.

@RyanDWilliamson Год назад

This is a great reminder of the past! Have you tried using an RLL controller on an MFM drive? We used to do that to gain additional space and speed.

@RandomRetr0 Год назад

You can Lube the platter spindle with a single drop of watch oil and it will quieten old drives significantly

@duramirez Год назад

I know the ST-225 "SFX" by heart, I love that HDD and it was part of my childhood, that spin up was not EXACTLY 100% what I remember, but well.... hehehe love to hear it again. Brings tears to my eyes. 😆 Thanks for this Porn. :D

@Bainderosa_Technologies Год назад

As you stated, most of these drives require the "park" command before turning them off. When I worked on the drives in the late 80s, early 90s, even the ones that supposedly had the park feature would fail early if you did not use the park command. I used Spinrite on a daily basis in those days, as it is great software for looking at your drive, though many drives had heads and platters that failed to respond to my attempts.