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camerongray
September 6th, 2013, 07:25 PM
Hi,

I have a IBM XT 5160 with a Seagate ST-412 10mb HDD. I am using the original XEBEC controller. When I got the machine I could browse the contents of the C: drive to an extent although many applications would result in a seek error. I have tried low level formatting using both the methods described here: http://www.uncreativelabs.net/textfiles/drives/XEBEC.DOC] and http://www.minuszerodegrees.net/ibm_xebec/ibm_xebec_llf_debug.htm. With both of these the drive runs for a couple of minutes while it does the format then appears to complete fine.

The issue is that when I'm in DOS (Booting from floppy), running 'fdisk' gives "Current Fixed Disk Drive: 1 ... Error reading fixed disk"

In total I think I have run the low level format twice, may it need more.

For a bit more information this is a 1986 XT and from the data that was on the drive before formatting, it appears that it was last used in 1994.

Any help would be greatly appreciated!

Cheers,
Cameron

modem7
September 6th, 2013, 08:03 PM
I have tried low level formatting using both the methods described here: http://www.uncreativelabs.net/textfiles/drives/XEBEC.DOC] and http://www.minuszerodegrees.net/ibm_xebec/ibm_xebec_llf_debug.htm. With both of these the drive runs for a couple of minutes while it does the format then appears to complete fine.
I would not expect either of those two low-level format methods to give you any form of feedback if a significant problem was encountered during the format.
Try instead the other two methods listed [here (http://www.minuszerodegrees.net/ibm_xebec/ibm_xebec_llf.htm)], with the preference being for SpeedStor.

camerongray
September 6th, 2013, 08:13 PM
The issue I have is that at this point in time I have no way to actually get data onto 5.25" floppies, is there anything else I can try until I can get one of my old machines fixed in order to do this?

modem7
September 6th, 2013, 09:50 PM
The issue I have is that at this point in time I have no way to actually get data onto 5.25" floppies, is there anything else I can try until I can get one of my old machines fixed in order to do this?
At [here (http://pcrepairclass.tripod.com/cgi-bin/datarec1/dbgreadmbr.html)] is procedure for using DEBUG to read the first sector from the hard drive, and then display the sector's contents.

How about you perform that procedure.

If the hard drive controller can not read the sector, then step 7 in the procedure will not show "NC" in the flags list (the "NC" in "NV UP EI PL ZR NA PE NC"). If "NC" is not shown, then there is no point in going any further in the procedure.

If the hard drive controller can read the sector ("NC" is shown), then step 8 will display the sector contents. If you had earlier performed the low-level format procedure [here (http://www.minuszerodegrees.net/ibm_xebec/ibm_xebec_llf_debug.htm)], then expect to see only bytes of 00 (because the second part of that procedure fills the first sector with 00).

Stone
September 7th, 2013, 02:55 AM
The issue is that when I'm in DOS (Booting from floppy), running 'fdisk' gives "Current Fixed Disk Drive: 1 ... Error reading fixed disk"There is a good chance that the drive (track zero) is hosed and that makes the drive a doorstop.

camerongray
September 7th, 2013, 10:17 AM
It doesn't show 'NC' and instead shows 'CY'. Assuming this means the first sector is bad? Is there anything I can try at all before having to hunt down a replacement drive (Which isn't easy)?

modem7
September 7th, 2013, 02:36 PM
It doesn't show 'NC' and instead shows 'CY'. Assuming this means the first sector is bad?
No. The BIOS is reporting that the controller can't read sector 0. There can be many causes.
However, because your controller can read certain sectors (you could at least do a DIR of C:), then a likely cause is a bad first sector.
But there could, for example, be a problem with your Xebec controller, a problem that results in bad reads of certain sectors.


Is there anything I can try at all before having to hunt down a replacement drive (Which isn't easy)?
Assuming that your drive is at fault, and that various portions of the platter surface have deteriorated, including the portion that is used for the first sector, then there is something you can try:

In 2006, member mikey99 had an ST-412 with a bad track 0. He was able to getting around that by using a very simple procedure.
Information and photos are in the post [here (http://www.vintage-computer.com/vcforum/showthread.php?3391-Seagate-ST-412-issue&p=28579#post28579)].

That procedure will only work if the 'new' position of track 0 ends up being on a good part of the platter.

Following that procedure, you will need to redo the low-level format, followed by FDISK/FORMAT.

modem7
September 7th, 2013, 06:40 PM
In 2006, member mikey99 had an ST-412 with a bad track 0. He was able to getting around that by using a very simple procedure.
Information and photos are in the post [here (http://www.vintage-computer.com/vcforum/showthread.php?3391-Seagate-ST-412-issue&p=28579#post28579)].

That procedure will only work if the 'new' position of track 0 ends up being on a good part of the platter.
The diagram [here (http://www.minuszerodegrees.net/hdd/hdd_cylinder_move_1.jpg)] will help explain what is going on.

We are not in a position to tell you how much the metal 'flag' needs to be extended by. It can not be extended by too much. In the fictional diagram that I referred to, track 0 can only be shifted by a maximum of 3 'channels'. One shift more, and track 899 would cease to exist.

camerongray
September 9th, 2013, 05:38 AM
Interesting, I may as well give it a go before going out and getting a new drive.

Am I right in thinking that the issue is that the first sector is essential for the drive functioning whereas other bad sectors aren't as big of an issue. Extending the arm will cause the bad area of disk to missed out and when low level formatting, the first sector will end up on a good area of disk?

mikey99
September 9th, 2013, 06:08 AM
modem7 , glad to hear that you remembered my ST-412 !

That ST-412 still works the last time I booted that system a few months ago.....

Stone
September 9th, 2013, 07:15 AM
Am I right in thinking that the issue is that the first sector is essential for the drive functioning whereas other bad sectors aren't as big of an issue. Extending the arm will cause the bad area of disk to missed out and when low level formatting, the first sector will end up on a good area of disk?That is essentially correct. Track 0 is required to be readable for the partition table to be written.

mikey99
September 9th, 2013, 01:27 PM
The head normally rests on Track 0, thats why its more likely to be damaged.
Its important to park the drive heads before moving the PC or the drive.
Parking the heads moves them to the last track on the drive.

camerongray
September 11th, 2013, 02:48 AM
Just to follow up.

Unfortunately moving the head to a different area still didn't help. The machine was a right mess when I got it (Bottom of case was so dented it was actually touching the motherboard (Amazed it worked actually, just needed C56 removed) so I imagine it had been bashed around without heads being parked. I also noticed that when the drive was spinning down you could sort of hear something like the head glancing against the platter.

The good news is that I found an untested ST-225 on eBay that I fitted, low level formatted and it works perfectly, didn't require any persuasion at all, it just worked! Only issue is that it's a half height drive and I don't have a blanking plate for the other space so I removed the faceplate from the ST-412 along with the LED, moved the little bit red plastic from the ST-225's faceplate into the 412's faceplate and precariously attached it in front of the drive. It's not great obviously but at least it looks decent, hopefully will be able to either get a blanking plate or a second half-height floppy (To free up the other blanking plate).

As far as parking heads go, It turned out my spare 5.25" drive is bad but I was able to hook up the XT's drive to a modern-ish PC, use XP to download the IBM Diagnostics Disk and SpeedStor (Amongst other stuff) and then boot the machine into Windows 95 (Safe mode) and write these files to 360k floppy. So I now have these disks I can use to park the heads.

Thanks for all your help so far!
Cameron