On Sunday (03/06/2011 at 06:06PM +0000), Tony Duell wrote: What a great topic... as I have been doing this exact effort for the past several weeks. I have completely cleaned and brought back online two RL02 and a third is just entering the process. Before I ever try to spin one up, I take the front panel off and remove the black pre-filter. It is guaranteed to be disintegrating and turning into a fine black powder. Exactly the kind of thing you don't want sucked into the drive. I vacuum out entire front area behind the front panel and the backside of the panel itself. I then take off the top covers and vacuum out the well where the pack sits and wipe the entire area down with a damp cloth. Clean out ALL the junk... cob webs, hairs, there will surely be a lot of junk in there. Then I clean out the rear near the fan. The fan blades will be loaded up with dust and I take off the grill and wipe those down with a Swiffer duster cloth as well as vacuum the whole fan assembly. Then there is the issue of the "absolute filter" which is the roughly 3" x 9" HEPA-like filter accessible from the front. I was fortunate to have one of these that was nearly new but others have been polluted by the disintegrating black foam pre-filter. I am currently looking at one that is completely black on the intake side-- totally loaded up with the black carbon-like dust that the pre-filter turns into. Not cool. I was just about to post to the list asking if there is a source for these absolute filters still (which I doubt) or if anyone has a process for rebuilding them? I've already stripped the filter element out of one and so I have an empty frame and am then considering modifying a HEPA filter for a room air cleaner or other appliance that uses a HEPA filter module. I will have to cut the filter to size and then glue it into the frame (similar to how these originals were made) using an elastomeric caulk or similar. But-- is there a better way?? After dust and dirt cleaning... then I clean the heads. I very carefully use a cotton swap soaked in isopropyl alchohol... 91%... drug store stuff... and rub it between the lower and upper head, sort of twirling it back and forth which removes the junk on the head pretty easily. I do this several times until the cotton swap comes out clean. At this point, I am brave enough to try to spin the drive up. I will take a known good not not precious pack and put it in the drive. You of course have to have a controller connected to the drive and powered on so that the drive gets clock over the interface. At this point you should have the fault light out and the load light lit. You can press load and hear the drive spin up. Hopefully. I have one drive that will spin up, attempt to load the heads and then immediately fault. After several experiments trying to get this drive to load the heads so that I could do some of the alignment procedures, I found that it was actually crashing the head into the media and I wrecked that pack. That drive is now a parts donor. I don't know exactly the failure mode but I suspect that the spindle is no longer aligned with the heads... due to some abuse like the thing being dropped. Dunno for sure. If you get to this point and the drive spins up and doesn't crash the heads then you can try to read the pack using one of the diags in XXDP2.5. I use ZRLMB1 which will read the entire pack and report the bad sectors found. On one of my drives I had consistent failures at cylinder 490 and beyond... which after performing the read amplifier gain adjustment procedure found here, http://bitsavers.org/pdf/dec/disc/rl01_rl02/EK-RL122-TM-001_techAug82.pdf the problem went away. I set the gain just slightly hotter than they spec on the theory that many of these packs are old now and probably produce a weaker signal than originally designed. I repeat the test across a selection of packs to get the average signal level too since I don't have a "standard" test pack (saw one on eBay for $1000 the other day!!) So, I have had good luck with 2 out of 3 RL02 so far. These filters might be an interesting challenge but I don't think insurmountable. Chris -- Chris Elmquist

Hello, On Sun, Mar 6, 2011 at 11:04 PM, Chris Elmquist <chrise at pobox.com> wrote: No need for blushing. Your posting was an interesting read for me (and I suspect a few others as well), and contains valuable information which can be applied in general, not only for the RL02 drive. IMHO, anyway. -- Regards, Torfinn Ingolfsen

On Monday (03/07/2011 at 09:31PM +0000), Tony Duell wrote: Yes. Sorry about that. I figured that out soon after and sent an apology post for changing the topic. It was not intentional... honest! What I am seeing is that the intake side of the absolute filter is completely black with dust from that decaying pre-filter. In fact, I tore an absolute filter apart yesterday to reclaim just the outer plastic frame and when I peeled the pleats apart, they were completely covered all the way in with the black dust. The pre-filter on this unit just crumbled when I touched it. I've also used 409 followed by just a damp wipe after that. Yes... that makes sense and I am likely to go back over the unit and do that level of tune up after I've determined it's worth investing that effort. As I found with the head crasher drive, spending a bunch of detail time up front sometimes doesn't pay off ;-) Yes. I've tried shopping by size on the web too... at all sorts of HEPA filter suppliers... but not so easy. I did find a couple sort of close (in size) filters at one of the DIY centers here... one was for a stand-alone room air cleaner and one was for a vacuum cleaner. I took one and peeled off the surrounding frame and cut it to size with a bread knife... and then glued it into the plastic frame I had scavanged from one of the real filters with elastomeric caulk. I haven't tried it in the drive yet. I'm worried that it won't take the pressure and will just blow right through the thing... so I need to rig the drive so I can spin it up without a pack in there and have the front air dam removed so that if it does blow it out, it goes into the room and not into the drive itself. I believe it was doing both actually. Sometimes it would get past the edge and onto the surface and then there'd be the tell-tale sound of oxide peeling off and then it would fault and unload (what was left of) the heads. Inspecting the guinea pig pack, shows a nice grove about 1/4" in from the outer edge on the upward facing surface. Dang. -- Chris Elmquist

On Sunday 06 March 2011, Tony Duell wrote: I have two RL02's on my 11/34C and one on my 11/83. I have a spare RL02 which I recently rebuilt (including new heads), and a working spare RL01. Given that I use RL02 packs regularly - especially on my 11/34C, I felt it critical that I carefully clean and verify packs as much as possible before mounting them in a RL0x drive. Let me say upfront that I've successfully used this procedure on the 32+ packs that I have in stock - which are all 100% - no bad blocks (some using substitute records, of course). I have six or seven packs in storage that did not pass initial "inspection", which I have never mounted in an RL02 for testing. I have not had one crash using a pack that passed this procedure. Tear-down / Clean Procedure --------------------------- Supplies/Tools needed: 1. Dust/Lint free wipes (such as KimWipes S-200) 2. Single ended swabs - 6" rigid white birch shaft 3. Absolute Isopropyl Alcohol (I use Zero Residue, 99.953% Pure Anhydrous) 4. Appropriate non-magnetic tip screwdriver(s) 5. High powered LED flashlight 6. Super clean well washed hands, dried with a lint free towel (or wipes). 7, Lint free clothing Environment: Room which is close to a dust free "Clean Room" as possible. I have a lab in my home which contains only electronic gear. It is far removed from any dust producing areas such as bedrooms, washer/dryers, etc. "Pet free" is also critical. Keep the door of such a room closed while doing this procedure. (No fans!) Procedure: 1. Most Digital packs have a Digital supplied "impact" detector. If it shows red - it's a warning that the pack has been mishandled by a drop or some other impact and may be damaged. It does NOT mean that the pack IS damaged. On the other hand, if the detector shows a clear/white indication, it does NOT mean the pack is O.K. to mount! 2. Clean the outside of the pack with wipes and alcohol. Remove all loose labels, adhesive, etc. 3. Hold the release and lift the handle as if you were going to place the pack in a drive. The protective bottom of the pack will be released. Put the bottom in a safe place (NOT the floor) while you work on the pack. 4. Place the handle in its normal locked position, and prepare to remove the plastic shield covering the bottom of the pack. Older packs will have small Philips head screws which should be completely removed. Newer packs will have "slots" which look like they are made for screwdrivers. There are eight such slots on a pack. Use a small flat head screwdriver to pry (outward direction) each slot until the plastic shield lifts. When the last slot is "released", or the last screw removed, the bottom will slip off. You will now be able to see the platter (bottom) completely. 5. Look carefully at the platter. Are there any scratches or "dings" on it? If so, you can stop here - and consider the platter not worth cleaning or testing. The platter's surface should be even and shiny (don't worry about dust - we'll deal with that later). 6. Now release the handle as if you were going to mount the pack. This will allow you to move the platter at an angle so you can see the top surface of the platter. Examine it for scratches or "dings" as you did for the other side. In the same manner, if you see scratches or dings, forget about using the pack. 7. Now hold the pack so that you can observe if it is "out-of-true". In other words, make sure that the platter is not warped in any way. This check is especially important if the impact sensor displayed "red". 8. Assuming that the platter looks good, we can now begin to clean it. Take a wipe and wrap it around the hard wood handle of the swab (it will take multiple turns of the swab to roll up the entire wipe). The rolled up wipe will just about cover the entire length of the swab. Holding the wipe so it doesn't unroll, put it into the alcohol. Remove the wipe and place it on the platter at an angle similar to a "spoke" on a bike. Holding the swab/wipe in place, spin the platter gently so that the entire surface of the platter becomes covered with the alcohol from the wipe. One pass (revolution) is usually all that is necessary. 9. Now look at the wipe. It should be clean - NO BROWN spots. If you see brown on the wipe, it means that there was probably a crash that you somehow missed on your visual inspection. 10. Assuming that the lint was clean (except for dust), we can now move on to the other surface. Remove the wipe, and place it in a safe place (we will use it later). Put a new wipe on the swab, dip it in the alcohol and do the same now for the other side of the platter. This is a bit trickier - but once you get the knack of it, it's easy. 11. Again look at the wipe. There should be NO BROWN spots. Assuming all is well, remove the wipe from the swab, and place it aside to be used later. We will now begin another visual inspection. 12. Shine a bright LED flashlight on the surface of the platter. If you hold it at the correct angle, you will be able to see any small particles which remain on either surface of the platter. If you've done the above correctly, there should be very few. Use a clean wipe (with no alcohol) to gently pick up any remaining particles. A little practice makes this easy. 13. Now place the handle of the pack in the locked position, and put the pack in a safe place. Put some alcohol on one on the wipes you used to clean the platter and use the wipe to clean the both sides of the plastic shield. Retrieve the pack and place the plastic shield on the pack. When you've lined it up correctly, all the screw holes or slots should line up perfectly (it only goes on one way!). If the pack had screws, replace them all. If it had "slots", gently snap the bottom back into place. 14. Do a final visual inspection of the platter using the LED flashlight. Don't worry if you see a speck or two of particulate on the shiny surface of the platter. The RL0x drive will blow off any remaining loose particles that happened to drift back on your platter while you were putting it back together. 15. Use the remaining wipe you used to clean the platter by pouring alcohol on it and using it to clean the pack bottom which you removed in step #3. Once you've cleaned it, put it back on the pack. 16. Now you are ready to test the pack. I usually use RT-11, and the DIR/BAD command. This will scan every block on the pack and tell you if any are bad. I typically then check to see if the pack is setup for RT, RSX, RSTS or UNIX and look at it's contents before using it. That's a totally different subject ;-) I may well do that - although I didn't get any "bites" for the Lorlin files. (And yes, everything else is standard RT-11 except for a few thousand test results in binary - of which I have no information as to what was being tested or the format/structure of the data). Cheers, Lyle -- Lyle Bickley, AF6WS Bickley Consulting West Inc. http://bickleywest.com "Black holes are where God is dividing by zero"

Tony Duell [ard at p850ug1.demon.co.uk] wrote: Given that it's an RL02, why not just image the whole thing? Compress it afterwards with 7z or something and it'll be, what, a meg or so? That's maybe half the size of the average HTML email :-) Antonio arcarlini at iee.org