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View Full Version : How "Defective" could this pack be?



NeXT
March 22nd, 2012, 10:49 PM
As part of my ongoing quest to fulfill my dreams in my signature, I have also been hunting for media for said device.
I picked up an HP 12940A which is essentially an RK05 DECpack.

http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/100_2651.jpg

The first thing you notice is that it has "DEFECTIVE" written on it. That could mean anything. Physically however both sides of the platter surface appear to be okay. Along with the pack there was an additional sheet of paper.

**LARGE IMAGE. CLICK TO VIEW** (http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/errata.jpg)

Apparently it had read errors. Not sure if this in the end rendered the pack useless or if the last user didn't think to try something else to remedy it like bad block mapping or reformatting. Is the pack at all salvageable from what we know?

Lou - N2MIY
March 23rd, 2012, 02:29 AM
It is most likely scratched from a head crash. Never put an RK or RL pack in a drive after it has had a head crash. The head flies so closely over the surface, the air film will be disturbed around the scratch. The head will likely then touch the scratched pack, and hurt or even irreparably destroy the head.

At this point, this pack is only good for doing gross mechanical alignments on a non-spinning drive.

Lou

PJMills
March 23rd, 2012, 05:00 AM
Hi,

I don't know about the 'defective' disk. My question is do you have a unit to read the device if it wasn't defective? I have 5 decPack's but can't read them. I don't own them but I'm pretty sure the owners would trade the packs for the information on them.

PJMills

NeXT
March 23rd, 2012, 07:30 AM
If I had the drive I would of already put the pack in however as Lou says,that would of been rather unwise.
I'll take the simplest advice given and that is to "leave it out of service". Damn.

barythrin
March 23rd, 2012, 09:39 AM
Interesting, sounds like the same issue Zip drives ended up with after the click of death. Supposedly a bad disk could do the same damage to a good drive if used (crappy and something to think about if buying used).

Chuck(G)
March 23rd, 2012, 10:33 AM
Interesting, sounds like the same issue Zip drives ended up with after the click of death. Supposedly a bad disk could do the same damage to a good drive if used (crappy and something to think about if buying used).

That one's almost as old as drives with removable media. I used to have a note from the early 1970s written by a night operator explaining how, by changing drives and packs, clobbered 7 CDC 844 drives and about 10 packs starting with a single bad pack. It read like the Gerard Hoffnung bricklayer story (https://www.youtube.com/watch?v=aI8ft3oZAik).

leaknoil
March 25th, 2012, 05:35 PM
It read like the Gerard Hoffnung bricklayer story (https://www.youtube.com/watch?v=aI8ft3oZAik).

That had me laughing pretty hard. I found this speech (http://video.google.com/videoplay?docid=-4182317635648274634) which has a lot of stuff I probably need to 60+ years old and British to get but, was still funny in places.

Chuck(G)
March 25th, 2012, 06:18 PM
Here's a text version of the story if you're not really good at understanding an old recording. (http://bluegum.com/Humour/Assorted/bricks.html)

The only other similar thing that comes to mind is Roadrunner and Wyle E. Coyote...

leaknoil
March 25th, 2012, 08:58 PM
Here's a text version of the story if you're not really good at understanding an old recording. (http://bluegum.com/Humour/Assorted/bricks.html)

The only other similar thing that comes to mind is Roadrunner and Wyle E. Coyote...

I got that part. The speech I linked is much longer. The bricklayer part is the easy bit to understand.

NeXT
March 25th, 2012, 10:56 PM
Took the pack to a friend this evening where we dismantled and cleaned the platter and then put it under a stereo microscope. On the topside we found one spot with an odd arrangement of scratches.

http://www.jax184.com/pictures/T1i_9652s.JPG

It looks too erratic to be the result of a crash though but otherwise, it IS probably why the pack was marked as bad. We didn't have any of the oxide come off during the cleaning though.

Compgeke
March 25th, 2012, 11:49 PM
That looks to me like it got some cookie crumbs or something in it, but it does look like whatever it was went on hard at one spot then slowly moved off, or slowly went on then off real quick.