RL02 failed once in XXDP - a problem?

[Roe]

I'm working on an RL02 disk drive, and it seems to work damn well. I've run all the XXDP2 5 diagnostics with one -- and only one -- error.

During the second pass of ZRLJC0 (drive test 2, SEEK) one error occurred. A summary is:

INC SK FWD HD 1 TEST
OPER: RD HDR
RESULT: INTRPT TOO LATE

Pass one worked with no error.

The question is: should I worry about it? Everything about the drive seems perfect, I've loaded old packs with no problem, all the rt11 format/verifynly and dir/bad return no errors...

Thanks.

 

[Qbus]

XXDP tends to run the systems way hard, you may want to check that the sliders that the head assembly moves on are clean with no dirt or lint on them. Don’t know what the requirement was for oil on the sliders but I put a small amount of light oil, like a drop on each slider so the head assembly moves with no issues. Also check to see that the two armored cables from the heads to the preamplifier are routed so they cannot bind or hang up, that’s not as easy at it sounds because you have to use that little holder and have just the right amount of slack for free and full length travel, and it has to be done in such a way that you cannot see them because the preamplifier sits over top of them when working. You can mount the preamplifier on its side for maintenance but the way you set the cables may not be right for the preamp in its normal location.
The drives are so huge and easy to work on can see them lasting for another thirty or forty years but my biggest fear is what happens to the preformatted media on the platters themselves? All the packs I have now are good but just how long will the formatting last?

 

[Lou - N2MIY]

I have thought about this problem as well (pack longevity). I have about one pack for each drive and am careful with them. Some day, push will come to shove and we'll need ways to have the platters recoated with a suitable material and then build a machine that has very precise head positioing to lay down new tracks. Mechanically, I could build that head positioner. The analog guts of an RL drive driven by modern hardware could format the tracks. We know every bit of the track formatting from Reinhard's work on his emulator.

I wonder if Athana already has the hardware to build and format packs. I have saved two scratched packs in the event there is a refurbishment process developed someday.

Lou

PS. I have also thought about the rarity of RK05 packs. I have two scratched RK05 packs. Fortunately they get low level formatted in the drive. Could one steal the platter from an RL02 and mount it in the RK05 cartridge? Could an RP06 pack be parted out similarly? Is there an industry standard for the OD, ID, thickness and coatings on these platters that would allow for mechanical interchangability of the platters?

 

[Marty]

Hi All;
Lou, Funny that You should mention this..
Years ago, when running TI 990's with CDC "Hawk" 9427 10 Megabyte (5 Removable 5 fixed) and It would have the start of a Head Crash, I would shut it down, and depending on the Head Damage.. I would always Replace the Fixed Platter, from a Removable Platter and sometime's the Heads as well.. Since I didn't have have an alignment Disk, I would align it to the tracks on the New to it Platter and then If I remember correctly I would Format the Fixed platter and copy the contents back on to it, and maybe sometime I could use what was on the New to it platter, If the alignment was good enough.. I can't remember for sure.. Anyway, I kept multiple backup tapes and disks, and platters, to keep things going..
So, Yes it can be done, even without an Alignment Disk..

THANK YOU Marty

 

[RSX11M+]

Roe - other responses notwithstanding, my first thought was: is the error repeatable or did it only occur once? A transient error may be indicator of something developing, or it could be drive movement during a seek. Was the drive mounted solidly and undisturbed during the test? Is it possible mechanical vibration of the unit or even floor played a part? I would not think this is anything to worry about if it doesn't re-occur. Susceptibility of older drives, including big ones, to movement of any kind is often a neglected consideration today. They will not be as tolerant as modern types.

 

[Roe]

Roe - other responses notwithstanding, my first thought was: is the error repeatable or did it only occur once? A transient error may be indicator of something developing, or it could be drive movement during a seek. Was the drive mounted solidly and undisturbed during the test.

Just the one error, and during the second seek test pass. The drive was, in fact, sitting on top of a short rack during the test, so I'm going to call it a transient and not worry.

The drive is working flawlessly. And surprisingly, all my RL02 packs (even a fairly cruddy old one with "SCRATCH PACK" scribbled on it in felt-tip marker) pass the worst-case write verification test with zero errors.

Thanks for the advice, everyone.

 

[tradde]

Just the one error, and during the second seek test pass. The drive was, in fact, sitting on top of a short rack during the test, so I'm going to call it a transient and not worry.

The drive is working flawlessly. And surprisingly, all my RL02 packs (even a fairly cruddy old one with "SCRATCH PACK" scribbled on it in felt-tip marker) pass the worst-case write verification test with zero errors.

Thanks for the advice, everyone.

When I see the words "scratch pack" I think of a pack that can be over-written as nothing
important on it. A "scratched" pack might mean a pack that has become defective. I'd
not be trying any packs that I wasn't sure of the surface.

 

[RSX11M+]

In my experience truely damaged packs were immediately rendered unloadable by destruction or disassembly. The term "Scratch Pack" would indeed mean - available for overwrite.