Miniscribe 8425S SCSI drive

[mitchW]

I just picked up an old Miniscribe 8425S SCSI drive, which sadly doesn't work, so I figured that I might be able to repair it someway.
It spins just fine, but it doesn't mount. When I want to format it with a HD SC Setup 7.5.3, it shows as uninitialized, and when I try to initialize it, it tries to initialize it for about 3 minutes, and then it fails (Format verification failed).

If I test the drive, it makes a "searching" sound, and then it says it failed its test because of the problems verifying data on drive.

In The Dead Mac Scrolls, it says that it might be repairable with DiskManager Mac version 2.24, which I don't have.

What do you think? Is a drive a dud or it might just be salvageable somehow?

 

[CelGen]

HD SC Setup fails drives drives for any number of reasons and I hate it.

Drive Setup however will less mercilessly perform an unconditional partitioning and format (saved a number of laptop SCSI disks that HD SC setup refused to touch) but you better go over the drive with a good disk utility to mark out any bad or failing sectors.

If Drive Setup doesn't work, that drive will never easily work on a mac again, mind you the 8425's were never great drives aside from the beautiful seeking noises they made.

 

[Scott Baret]

You may want to track down a copy of Silverlining. It's a better formatting program and works on all drives, Apple-branded or not.

Fourteen years ago, I remember formatting a drive with Silverlining. It was an 80MB in a Mac SE/30 and, by all means, should have been dead. Miraculously, it came through after several hours of formatting. That drive didn't last much longer due to mechanical problems and a lot of space was lost due to bad blocks, but it was enough to make it through the following spring, when I had the SE/30's internal speakers playing some pretty hefty sound files, more or less as a proof of concept.

 

[mitchW]

Thanks for the info. Yes, I agree that the stepper motor sound is very nice, probably on the par with an old ST-225 and ST-251.

I found the Silverlining here:https://www.lacie.com/us/support/drivers/driver.htm?id=10052

Is this the right version? It looks a bit newish, but it seems to work on my PB G3 Wallstreet under 9.0.4 wiithout problems.

I am currently formatting this drive, and it throws up quite some read errors, but every format pass I do, there are less errors, so it is promising.

Less promising is the fact that it throws 101 erros when running Drive Hardware Test, under Drive's internal memory-test...

 

[RalfK]

> I am currently formatting this drive, and it throws up quite some read errors, but every format pass I do, there are less errors, so it is promising.> Less promising is the fact that it throws 101 erros when running Drive Hardware Test, under Drive's internal memory-test...
A SCSI-Harddisk formatter sends out a single format command to the harddisk controller which knows how to format the surfaces. The external software is just able to control some details as sector size, retry count, cache management, ...

After the formatter software sends out the command it waits for the result. If the harddisk controller tells an error then that's it. The software normally cannot repair local problems within the harddisk controller.

You can ask the harddisk controller for a list of defect sectors. You get two different values: the primary list tells you the sector numbers which are defect after production, the grown list are the defects since than. The first dozen (or hundreds, it depends on the capacity, the model, ...) errors are handled locally because there are some spare sectors. But the number of spare sectors is not endless.

This means: if you see the number of "grown errors" is growing you know that the death of the harddisk is in the near future.

Sorry for that, but I think that your Miniscribe is nearly dead because the formatter throws a lot of errors.

 

[techknight]

I think with stepper drives you have to specify an interleve and low level format it..

Lido will do that.

Stepper drives tend to get misaligned over the years and high level formats fail. Low level formatting laying out the new tracks at the proper interleave should fix it.

 

[RalfK]

I think with stepper drives you have to specify an interleve and low level format it..

The SCSI command "format" is the low level format.

The default interleave is 1. So you better change the interleave to 2 using a Mac SE and 3 using a Mac Plus. Although the hard disk will function with a non-optimal interleave.

 

[CelGen]

Sorry for that, but I think that your Miniscribe is nearly dead because the formatter throws a lot of errors.

It's a miniscribe. Wad'dya expect?

I think with stepper drives you have to specify an interleave and low level format it..

For MFM and RLL interface drives yes but it's much less common for LLF commands to work on stepper drives with IDE/SCSI interfaces due to the higher level translating logic required.

In theory you can slap on a regular 8425's control board and LLF with that but the geometry will change when you swap back to the SCSI interfaced board.

This is why in the MFM/RLL/ESDI world if you formatted a drive with one controller card, you're stuck with the controller forever if you want to read the data back. Plug it into another controller and there's no promise the drive will be useable until after you format it.