MicroPDP-11/83 H960 Rackup and Such

[czunit]

Nicely done! Interesting about the conversion, early RL01 drives that I had used the brushes thing to "clean" the pack. Not a great idea, was removed from later units.

Glad to help and pleasure to meet you. If anyone comes across a CDC 9457 Lark power supply/SMD control let me know

 

[DDS]

Is that little access port on the side the one that allows you to override the lid interlock? My RL02 with the dorked up interlock doesn't have one. So I have to dink around with the rear cover in order to dink around with the lid in order to access the pack. It's on my list of things to fix. Not exactly a short list.

>.<

Perhaps something that DEC left off of the later drives like the pack brushes?

 

[glitch]

Nicely done! Interesting about the conversion, early RL01 drives that I had used the brushes thing to "clean" the pack. Not a great idea, was removed from later units.

I've read about those, but never seen one in real life -- seems like a great way to carry particles back *onto* the platter.

Glad to help and pleasure to meet you. If anyone comes across a CDC 9457 Lark power supply/SMD control let me know

Will do!

Is that little access port on the side the one that allows you to override the lid interlock? My RL02 with the dorked up interlock doesn't have one. So I have to dink around with the rear cover in order to dink around with the lid in order to access the pack. It's on my list of things to fix. Not exactly a short list.

>.<

Perhaps something that DEC left off of the later drives like the pack brushes?

All of my RL02s have the access panel to release the interlock, I believe all of my RL01s have it too, but I can check. What's messed up on your interlock? I have spare parts now

 

[czunit]

Maybe. But I remember at least one of my early RL01's did not have the port and I had to do the remove the top to get the door open. Real pain in the rear, it was a drive with the heavy metal front panel.

 

[glitch]

Yesterday we got a mouse messed RL01 out and cleaned it up. There was a pretty serious mouse nest behind the front panel, but it mostly stayed ahead of the cooling air screen. Some mess made it to the PSU area, but it's unclear if the mouse traversed the air:air heat exchanger, or if the cooling air filter disintegrated during transport and some of the mess migrated by inertia. This is one of the two I picked up after VCF East this year. Anyway, it's currently on the small Steelcase desk next to the H960 rack:



It's chewing on a scratch pack, above. I started with the "CAT pack," mentioned in the pack cleaning writeup from years ago, but the CAT pack is apparently failing. I kinda remember it being not great when RetroHacker_ and I started getting my first RL01 drives in shape. It has higher vibration than typical, and takes longer to go READY. It gives mixed hard and soft errors, but functions enough to start to give its directory listing (it had been INITed and CREATEd under XXDP when RetroHacker_ and I had it going), and the pack label and bad block tables are readable. I'm guessing the platter is off-center in the hub from dropping or something. I don't think it's warped, it looks nice and flat, and does not ping. Oh well!

Today we'll be using the scratch pack tested last night for the RL performance exerciser. Then we'll know if it's surviving well or not

 

[glitch]

So, the reason I'm going through RL01 drives is I want a RL01 and RL02 in the rack with the MicroPDP-11/83 to make dumping/writing/testing/working with them easier, so I don't have to use the machines the RLs will normally be attached to for it, which are all much slower than the 11/83. The plan is to mostly work with the packs under 2.11BSD for archiving. This was the final RL01 I was working on, and ran into problems with cylinders past 49 but only during writing. I figured it was an alignment issue, which it wasn't, but I did finally have to set up to align one:



Turns out it's not that bad

 

[glitch]

I think maybe the RL02 I've been running with since the start of this thread is having An Issue. I noticed a funny noise when unloading the heads with the drive connected to the PDP-11/34a for running XXDP. It's now A Funny Noise every time the heads are on the outer tracks. I'm not getting any oxide on the heads or off the platters, and all three of my usual test packs do it. I'm pulling the drive out of service immediately, it's a very not comforting noise. I'm wondering if it started as a smaller noise and I just didn't hear it over the wind tunnel airflow of the PDP-11/34a. In a room without the 11/34a running, it sounds Very Not Good.

I would describe the noise as sounding like a bearing is going dry in something.

The noise is completely absent on the inner tracks. I have it cabled to the RLV12 now, testing with NeXT's repaired KDF11-B in the MicroPDP-11/83's chassis.

 

[czunit]

Wow. Lucky you have a complete head/positioner spare assembly.

Could be the bearings on the side of the head rails, I've never heard them have a problem, but it's possible. May be time for a bit of lubrication, but you don't want any oil that could then be thrown onto the pack itself.

 

[glitch]

Wow. Lucky you have a complete head/positioner spare assembly.

Haha, right?! Probably exactly where that one is going...pretty much can't go wrong with keeping spare parts.

Could be the bearings on the side of the head rails, I've never heard them have a problem, but it's possible. May be time for a bit of lubrication, but you don't want any oil that could then be thrown onto the pack itself.

I did relubricate the slide bearings with no change, not sure if there's others I missed like in the positioner. I use a little DTE Light in a needle oiler and use a very small amount, work the positioner back and forth (with a Kimwipe between the heads), and then remove excess oil/old lubrication with a swab. Figure I want *zero* extra oil since it whips the heads around pretty fast!