• Please review our updated Terms and Rules here

Seagate ST351A/X LLF?

P

Phil Saunders

Experienced Member
Joined
May 25, 2014
Messages
95
Location
Milton Keynes, United Kingdom
I have a ST351A/X (jumpered for XT) connected to a Acculogic S/IDE XT-IDE controller card. The card has a WD BIOS with LLF program in ROM, accessed with the usual G=C800:5.

Is it safe to use this to format the drive? It has previously been used with some weird partitioning and dual-booting software, and it's completely messed up.

There seems to be conflicting info - some people say don't LLF an IDE drive EVER, others say it's fine. There IS a sticker on this particular drive that says DO NOT LLF, but I have 3 other identical drives that don't. If it's not safe, why would the program be in the ROM?

Is there a definitive answer as to if this can be done safely?
 
My ST351A/X has a "Do Not Low Level Format" sticker, but I've low level formatted it before.

I only did so because I'd seen my exact situation done before after searching google groups (old newsgroup postings). I probably wouldn't attempt it outside that situation unless the drive was dead without it (and then I'd try and find old versions of Seagate's tools first).

I did find posts in google groups where it had gone badly - I suspected it was to do with the CHS values used (native vs translate) - but was never really sure and didn't have enough of them to experiment with!
 
SpidersWeb said:
My ST351A/X has a "Do Not Low Level Format" sticker, but I've low level formatted it before.

I only did so because I'd seen my exact situation done before after searching google groups (old newsgroup postings). I probably wouldn't attempt it outside that situation unless the drive was dead without it (and then I'd try and find old versions of Seagate's tools first).

I did find posts in google groups where it had gone badly - I suspected it was to do with the CHS values used (native vs translate) - but was never really sure and didn't have enough of them to experiment with!
Click to expand...

Thanks for that - I guess what I really should have asked was - if I do it and it fails to resolve my problem will it be recoverable with the correct software?
 
I believe this exact issue was discussed in another thread quite recently. IIRC, the result was that running the LLF software for this (and other drives as well) drive results in nothing actually happening other than an elaborate ruse to convince the operator that the drive has been LLFed when in actuality, it hasn't. IOW... run the software; it doesn't really do anything, anyway.
 
Stone said:
I believe this exact issue was discussed in another thread quite recently. IIRC, the result was that running the LLF software for this (and other drives as well) drive results in nothing actually happening other than an elaborate ruse to convince the operator that the drive has been LLFed when in actuality, it hasn't. IOW... run the software; it doesn't really do anything, anyway.
Click to expand...

This would make sense, but if no harm could come from it.... then why would they put the sticker on?
 
I think there are three categories:

1. Does nothing
2. Does damage
3. Used to switch the drive between available geometries (e.g. my early ST157A)
 
I think there might be safer ways to zero out the drive. I haven't need to do it in the past, but there must be a tool out there.
 
Phil Saunders said:
... which brings me back to the original question :D
Click to expand...
Your original question is, "Is it safe to use this to format the drive?"

The only authoritative answer is from the drive maker, and the maker has put a "DO NOT LLF" on the drive. Unless information surfaces from the maker as to WHY they put the sticker on the drive, then the answer to a "is it safe to LLF (using whatever)" type question has to be 'unknown'.
 
Phil Saunders said:
I have a ST351A/X (jumpered for XT) connected to a Acculogic S/IDE XT-IDE controller card. The card has a WD BIOS with LLF program in ROM, accessed with the usual G=C800:5. [...] If it's not safe, why would the program be in the ROM?
Click to expand...
Because the LLF program belongs to the controller card and not the the hard disk. Whether it's safe or not depends on the hard disk connected. If the hard disk tells you not to low-level format it, then better don't do it. IDE drives have a very tight binding between the drive mechanics and the (integrated) drive electronics. Because of this, a LLF could render the drive unusable, as it may destroy the pre-recorded servo tracks among other things.
 
Last edited:
My hazy knowledge, now 25 years old, is that LLF an IDE drive destroys it.

What I remember is that the dramatic increase in storage capacity was due to the track servo positioning information being stored on the actual platter. With the ST506 drives there was just the data information, IDE added positioning information as well. An ST506 used a stepper motor, so one step was one track, an IDE drive used a DC servo motor so no direct correlation between a step and a track.

Doing a LLF erased that and the drive was henceforth useless. But, I also remember that the drive wouldn't let you do a LLF?
 
Another reason is the use of zoned recording. That is, more sectors are packed into outer tracks than inner. The notion of a uniform geometry CHS is a fiction on many of these drives.
 
Timo W. said:
Because the LLF program belongs to the controller card and not the the hard disk. Whether it's safe or not depends on the hard disk connected. If the hard disk tells you not to low-level format it, then better don't do it. IDE drives have a very tight binding between the drive mechanics and the (integrated) drive electronics. Because of this, a LLF could render the drive unusable, as it may destroy the pre-recorded servo tracks among other things.
Click to expand...

Yes.... but the BIOS chip is on an XT-IDE controller card, so it HAS to be connected to an IDE disk. Bottom line seems to be that nobody knows for sure - even Seagate can't help - it's just too old for anyone to still have the relevant knowledge. I'll probably try SeaTools for DOS (if I can find an ancient version anywhere for download) and zero it out before I try the BIOS program.

Whatever happens the drive is garbage right now, so nothing to lose :)

Does anyone know how the factory format (whatever it is) was put on the drive in the first place? Is it just software with the standard drive as installed, or is there non-PC hardware involved?
 
If it's a drive with a servo track, it uses a very special setup to write that track. I recall seeing one at Taondon's R&D setup on Coleman Road near the San Jose airport. It was a rig using a pneumatic cylinder and a laser interferometer positioner all bolted to a 4" thick granite slab. I don't know what was used for production--or even what was used for the aforementioned Seagate drive.

However, if you dig up a copy of PC-3000 ISA, it claims to have a utility to LLF an ST351A/X. I think it originated out of Russia.
 
Phil Saunders said:
Yes.... but the BIOS chip is on an XT-IDE controller card, so it HAS to be connected to an IDE disk.
Click to expand...
As I wrote, it depends on the hard disk connected. No one said that there aren't any IDE drives that *are* safe to low-level format. If the drive has a stepper motor, it's probably safe; if it has servo tracking, it's probably not. But again, the drive you are asking about has a sticker telling you not to do a low-level format. This comes from the manufacturer and you won't get a better anwser than that.
 
Timo W. said:
Because of this, a LLF could render the drive unusable, as it may destroy the pre-recorded servo tracks among other things.
Click to expand...

Not in this case, because the ST-351A/X is a stepper motor drive (allegedly the last one ever made!).

Also, Seagate's spec sheet for the ST-351A/X says "Already low-level formatted at the factory for AT installations" -- but it doesn't say anything about XT installations, so maybe that implies that an LLF may be needed for XT systems.
 
Last edited:
vwestlife said:
Not in this case, because the ST-351A/X is a stepper motor drive (allegedly the last one ever made!).


Also, Seagate's spec sheet for the ST-351A/X says "Already low-level formatted at the factory for AT installations" -- but it doesn't say anything about XT installations, so maybe that implies that an LLF may be needed for XT systems.
Click to expand...

Yes of course! I should have known this - a stepper drive always knows what cylinder it's on (or it can re-calibrate and count from 0 if necessary), so there's no need for an embedded servo.

I did read the 'Already formatted.....' on the spec sheet, but then got confused by the 'Don't ....' sticker. I just assumed this meant that it had a special factory format, and stopped thinking at that point!

I've read elsewhere that it's possible to write data on an AT, then jumper it for XT mode and successfully read the data, so I don't know why the spec sheet specifies that it's formatted for AT. Might have something to do with the possibility of the drive being configured for something less than the full capacity in XT mode?

Thanks to Stone, I now have SeaTools so I'll give it a try.
 
Phil Saunders said:
I've read elsewhere that it's possible to write data on an AT, then jumper it for XT mode and successfully read the data,
Click to expand...

In my experience, that is true.

so I don't know why the spec sheet specifies that it's formatted for AT. Might have something to do with the possibility of the drive being configured for something less than the full capacity in XT mode?
Click to expand...

Or, whereas an AT system can usually be assumed to work fine with a 1:1 interleave, a slower XT system might need a higher interleave -- indeed, 3:1 is common for IDE-XT drives (such as the ones in IBM's PS/2 Models 25, 30, and 30-286).
 
You must log in or register to reply here.
Back
Top