That was tough, but I think I dug it up - https://web.archive.org/web/20020118102950/ht … isplayItem=1459
Cylinders: 731
Heads: 7
Sectors/track: 17
Bytes/sector: 512
Interface: ST‑506/412 MFM
Data rate: 5 Mb/s
Write precomp: 732
Landing zone: 732

And yes, it's listed under Citoh, but the YD suggests it was a rebrand or merger

Matth79 wrote on 2025-09-17, 13:18:

That was tough, but I think I dug it up - https://web.archive.org/web/20020118102950/ht … isplayItem=1459 Cylinders: 731 Heads: […]
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That was tough, but I think I dug it up - https://web.archive.org/web/20020118102950/ht … isplayItem=1459
Cylinders: 731
Heads: 7
Sectors/track: 17
Bytes/sector: 512
Interface: ST‑506/412 MFM
Data rate: 5 Mb/s
Write precomp: 732
Landing zone: 732

And yes, it's listed under Citoh, but the YD suggests it was a rebrand or merger

Wow, that's some good digging and certainly looks to be a match! The luggable in question though does not seem to like it. It gives me the following drive types to pick from (seemingly no option to enter custom values) and none of them match. I've tried types 1,2,5,7, and 8 so far but no dice. Pretty sure the drive is original to the machine as the mounting screws definitely seem like they had never been undone

moistyalf wrote on 2025-09-18, 09:22:

The luggable in question though does not seem to like it. It gives me the following drive types to pick from (seemingly no option to enter custom values) and none of them match. I've tried types 1,2,5,7, and 8 so far but no dice.

Type 7 seems like a perfect match, that cylinder count usually includes landing zone. Whad do you mean by "does not seem to like it"? No boot? Any weird noises coming from that HDD?

Deunan wrote on 2025-09-18, 09:41:

moistyalf wrote on 2025-09-18, 09:22:

The luggable in question though does not seem to like it. It gives me the following drive types to pick from (seemingly no option to enter custom values) and none of them match. I've tried types 1,2,5,7, and 8 so far but no dice.

Type 7 seems like a perfect match, that cylinder count usually includes landing zone. Whad do you mean by "does not seem to like it"? No boot? Any weird noises coming from that HDD?

Pretty much, POST takes ages, then throws a "fixed disk 0 failure". Hard drive spins and makes normal-ish sounding seek test noises but then clunks and shuts down. Just had a look now, there's a pair of LEDs on the HDD's controller board, a green and red one. The green lights up whenever power is applied and the red seems to be a fault indicator of some sort, as once it spins down it starts flashing in a pattern, presumably some kind of error code. Looks like this drive is dead unfortunately

7 heads means it probably has a dedicated servo side on the last platter with a voice coil actuator.

Maybe servo calibration fails?

moistyalf wrote on 2025-09-18, 09:55:

Pretty much, POST takes ages, then throws a "fixed disk 0 failure".

That seems like a HW problem, but there are possible explanations:
- If the drive was LLF with different controller then this one might not be able to find sector headers or data, this can lead to what seems like a hang or very long pause and HDD error thrown by BIOS. Try a LLF unless you really want to recover the previous data and suspect that something else than HDD itself is causing this.
- There are some signals that HDD outputs and the controller needs to work properly, like seek complete, index, etc. Misconfigured jumpers or DIPs can cause the HDD to not respond properly and confuse the controller, and BIOS.

Clunking noises are usually not bad, unless you hear them on each seek. Parking/unparking can be quite noisy on these old HDDs. What you really don't want is any hints of metal on metal scraping, might not be very obvious sometimes and only appear on spin-up and down. That is usually a very bad sign of ripped off heads.

With 7 heads (probably 8 with a servo surface as it was already noted) I'd expect the drive to be modern enough to do some sort of self-check on spin-up. Now this is different for each HDD type, but in general it's kinda like IDE, some "head dancing" and then seek noises stop. This should happen even when powered without any control cables attached. But it might not park itself, so do not subject the HDD to up-down vibrations if you can, unless you can hear a clunk during spin-down, which would suggest the auto-park works.

Deunan wrote on 2025-09-18, 13:32:

That seems like a HW problem, but there are possible explanations: - If the drive was LLF with different controller then this on […]
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moistyalf wrote on 2025-09-18, 09:55:

Pretty much, POST takes ages, then throws a "fixed disk 0 failure".

That seems like a HW problem, but there are possible explanations:
- If the drive was LLF with different controller then this one might not be able to find sector headers or data, this can lead to what seems like a hang or very long pause and HDD error thrown by BIOS. Try a LLF unless you really want to recover the previous data and suspect that something else than HDD itself is causing this.
- There are some signals that HDD outputs and the controller needs to work properly, like seek complete, index, etc. Misconfigured jumpers or DIPs can cause the HDD to not respond properly and confuse the controller, and BIOS.

Clunking noises are usually not bad, unless you hear them on each seek. Parking/unparking can be quite noisy on these old HDDs. What you really don't want is any hints of metal on metal scraping, might not be very obvious sometimes and only appear on spin-up and down. That is usually a very bad sign of ripped off heads.

With 7 heads (probably 8 with a servo surface as it was already noted) I'd expect the drive to be modern enough to do some sort of self-check on spin-up. Now this is different for each HDD type, but in general it's kinda like IDE, some "head dancing" and then seek noises stop. This should happen even when powered without any control cables attached. But it might not park itself, so do not subject the HDD to up-down vibrations if you can, unless you can hear a clunk during spin-down, which would suggest the auto-park works.

As best I can tell, the drive is original to this machine, but you can never be exactly sure. Certainly no tell-tale signs of it being removed before and given how damn tight the mounting screws were (and not chewed up in the slightest) it points to it being fairly original, but who knows

My best interpretation of the drive sounds are: spins up, stepper moves to one side slowly, then back to the other, then the stepper seems to move a tiny bit one back and forth, pauses, does this again a few times, then clunks (presumably head parking), the drive spins down and starts blinking its red LED. No metallic or grindy-crashy head noises. It does this even with no data cables connected

While I would still like to revive the original HDD if possible, for now it would be nice to get this thing up and running with a more modern flash based solution. Problem is, there's no built in IDE or SCSI and no ISA slot either being a luggable/"laptop", which rules out things like the XT-IDE. I suppose I could run the whole thing off a Gotek but having to swap disks constantly is going to be finnicky. Any other suggestions?

There is some kind of expansion slot at the back of the machine but I've got no idea what it is, possibly for a memory expansion board?

moistyalf wrote on Yesterday, 08:26:

My best interpretation of the drive sounds are: spins up, stepper moves to one side slowly, then back to the other, then the stepper seems to move a tiny bit one back and forth, pauses, does this again a few times, then clunks (presumably head parking), the drive spins down and starts blinking its red LED. No metallic or grindy-crashy head noises. It does this even with no data cables connected

Hm. I wonder if the servo surface got so weak that it no longer provides correct signals, or perhaps there is a problem with the heads. These HDDs can be opened to see if there is any damage to platters - but it's not always obvious with this many platters, especially the bottom sides. Might provide some clues though. Anything seems loose inside if you rotate the HDD in your hands?

Before you open it, try reseating all the connectors and cables, the head FFC especially. I see 2 trim pots on the PCB, rotate those a bit and return to original position - in case it's some sort of bad contact issue. Consider unplugging the entire PCB and cleaning it, at least with a soft brush, from any dust and dirt.

If you want to open the platter case also have a clean soft painting brush prepared for any dust removal. There might be a gasket around the cover that is old and will start to shed, you want that debris removed. After removing the screws (and any stickers that have to go) pry the cover up gently in several places, do not force it open on one side. I've opened quite a few of these HDDs, in most cases having clean and dry hands, as well as not shedding hair into the drive case, is enough to keep it clean and working. There should be a filter inside to catch any dust particles that might get in there anyway.

As for possible replacements... that's tough, I've only seen a few MFM emulators and these were always expensive. Might be difficult to find another HDD that fits in the space there too.

There is always the possibility to hardwire an ide controller in. You only need to find the corresponding signals. As you maybe have a documented chipset, you can look up the signals there.
It's fiddly but doable.

Deunan wrote on Yesterday, 11:19:

moistyalf wrote on Yesterday, 08:26:

My best interpretation of the drive sounds are: spins up, stepper moves to one side slowly, then back to the other, then the stepper seems to move a tiny bit one back and forth, pauses, does this again a few times, then clunks (presumably head parking), the drive spins down and starts blinking its red LED. No metallic or grindy-crashy head noises. It does this even with no data cables connected

Hm. I wonder if the servo surface got so weak that it no longer provides correct signals, or perhaps there is a problem with the heads. These HDDs can be opened to see if there is any damage to platters - but it's not always obvious with this many platters, especially the bottom sides. Might provide some clues though. Anything seems loose inside if you rotate the HDD in your hands?

Before you open it, try reseating all the connectors and cables, the head FFC especially. I see 2 trim pots on the PCB, rotate those a bit and return to original position - in case it's some sort of bad contact issue. Consider unplugging the entire PCB and cleaning it, at least with a soft brush, from any dust and dirt.

Nothing loose inside that I can feel. Definitely worth trying that, don't have much to lose at this point.

I have revived a couple of old Quantum SCSI hard drives that were common in the old Macs, some of them have a rubber end stop that rests against the back of the head arm next to the magnets when the heads are parked. Over time this turns to sticky goo which locks the arm in place, combine that with head stiction and you get a drive that doesn't want to move at all. I've had a decent run taking the covers off in a relatively clean environment and freeing them up. Definitely wouldn't trust them long term but gets them going long enough to image at least. Never had a stepper driven HDD apart before though

It's alive!!

Fiddled with the connectors on the board variously and got nowhere. Took the cover off and watched the drive initialise. My interpretation of the noises was actually back to front, what i thought was it sweeping the heads over the platter was just a slow movement back and forth at the very edge, and the quick back-and-forth sound was it sweeping the entire platter very quickly. But this time, with the cover off, it stopped sweeping every few seconds, shuffled the heads a bit, red light came on solid, and it stayed spinning! Put the cover back on loosely with 3 of the screws, put it back in the computer and whaddya know, no more fixed disk error

No idea how long it will continue to last given the cover has been off, wasn't off for long and kept it as dust free as possible. Its almost like it wanted the cover to come off in order to come back to life