How to reformat DEC RL02 diskpacks?

[Al Kossow]

We didn't have access to a clean room

You don't need one for what you did.
The important thing is to make sure there is no residue left from the cleaning process.

You also should inspect and clean the heads immediately after HDI.

 

[glitch]

You also should inspect and clean the heads immediately after HDI.

HDI? We did clean the heads, as well as wiping down the inside of the drive well, before we attempted to mount any of the packs. Even the cleanest looking heads had an observable amount of contamination after swabbing.

 

[RSX11M+]

RetroHacker_ and I disassembled a small pile of RL01/RL02 cartridges for inspection and cleaning a few months back. I haven't written up the exercise, but following various DEC guides and processes outlined online, we were able to clean up and inspect all of our packs, preventing the mounting of at least one hard crashed pack (it had "Saturn rings") that was both very clean on the outside and had a non-tripped ShockWatch stuck to it. We didn't have access to a clean room, but Kimwipes, lint-free swabs, 99% isopropyl alcohol, a bright LED flashlight and RetroHacker_'s kitchen resulted in no damaged packs.

Thanks for weighing in. Of course, more juicy details would be great, but one thing I have to ask about "DEC guides and processes outlined online"...

Can you please provide pointers? [links]

This subject is worth a knowledgeable article on the forums here, as it keeps coming up.

 

[rorypoole]

Controller for RL02/RL01 disk drive in a PDP8 straight 8
http://www.vintage-computer.com/vcf...for-RL02-RL01-disk-drive-in-a-PDP8-straight-8

If the pack has a shockwatch on it, I would agree with Lou. In your case, with a pack actually being in the drive during transport - it would count for the condition of both.

Was the pack easily removed from the drive?
Was there any indication that the heads were on the platter while the drive was unpowered?

If the heads were in the retracted and locked position, and there is an untriggered shockwatch - the only thing I'd look for is contamination and corrosion. A flashlight examination of the platter should be sufficient for this.

However, it would be a very good idea to check out the drive on another system, rather than try to debug your PDP-8 and a suspect RL drive at the same time. Is there any indication what system the RL was last in service on?

Lou, were RL02 disks ever used on PDP-8 systems in the day? Wouldn't they have been RL01? I am pretty sure the bus controller would be compatible, but software is another matter.

Incidentally, I am unaware of any RL02 that ever had a brush. I think the brush was eliminated before introduction of the RL02.

I took the diskpack back in my backpack on the train, but when I could not open the RL02 drive when I got home, I feared a stowaway diskpack! but I have been informed its a safety interlock but there may still be a diskpack larking in there!, and I have not powered it up as I need to know more about it, and I dont have time at the moment, as I will be off soon for 2 months!
It has a US 240v plug on it? I also picked up a rack mount DEC 861B power controller with 240v us sockets on it, but it needs a bit of work.
the RL02 drive and lots of other stuff had resonantly moved by movers, and they where not careful and had damaged a pdp8, the RL02 drive was face down when I got there, I put thick card under and behind it and tied it to my sack barrow with a few other items, and the RL02 could have been used with a PDP11 so could have 16 bit diskpacks!!!! and if so I will have a pdp11 based I/O processor to make it work!!

RetroHacker_ and I disassembled a small pile of RL01/RL02 cartridges for inspection and cleaning a few months back. I haven't written up the exercise, but following various DEC guides and processes outlined online, we were able to clean up and inspect all of our packs, preventing the mounting of at least one hard crashed pack (it had "Saturn rings") that was both very clean on the outside and had a non-tripped ShockWatch stuck to it. We didn't have access to a clean room, but Kimwipes, lint-free swabs, 99% isopropyl alcohol, a bright LED flashlight and RetroHacker_'s kitchen resulted in no damaged packs.

I would love to read read about that, any pics? and where did you get a "small pile of RL01/RL02 cartridges"?? dont bin the crashed pack as it can still be useful!

I dont know if the RL02 drive had its heads in the locked position? next time I will lock the heads before I leave
I have a mystery 20mb disk pack? with a spare platter its very dirty so I dont think it could be used, but I could use it to practice cleaning and inspection?
http://www.vintage-computer.com/vcf...390-mystery-20mb-disk-pack&highlight=diskpack

 

[glitch]

I would love to read read about that, any pics? and where did you get a "small pile of RL01/RL02 cartridges"?? dont bin the crashed pack as it can still be useful!

Yes, there's pictures! I'll see if I can find some time to write it up on the 4 JUL holiday. Disk packs seem to be a little more common on this side of the pond.

Unfortunately for the crashed pack, it is of little use other than as maybe wall decoration, or a clock face! We nabbed the pack shield and dust cover for another drive since they were in very good shape. They're quite useless once crashed, as a crashed pack can crash your drive, which will create more crashed packs. We decided that no pack that we even suspected of being damaged was to be mounted in any of our gear...that included things like high vibration on loading.

I dont know if the RL02 drive had its heads in the locked position? next time I will lock the heads before I leave

If you open the door covering the drive well and take a look at the slot where the heads stay, it should be pretty obvious as to whether they are parked and locked. There's a metal tab that swings over the opening for the heads, when it is up they are locked and /can not/ enter the well. If your cover solenoid is still working, you won't be able to open the door without the drive powered on. There's no need to lock the heads unless you're moving the drive a fair distance. We don't lock the heads on any of our equipment if it's just moving around the shop.

I have a mystery 20mb disk pack? with a spare platter its very dirty so I dont think it could be used, but I could use it to practice cleaning and inspection?
http://www.vintage-computer.com/vcf...390-mystery-20mb-disk-pack&highlight=diskpack

Dirty on the outside doesn't make a difference as long as it's clean on the inside! One of our filthy RL02 packs was fine on the inside and even included a copy of RT-11 4, still bootable, and no bad blocks. It doesn't look like there was any conclusive decision on whether your mystery pack is in fact a DEC-compatible RL0x pack though. Still, it would be fine to practice with.

 

[rorypoole]

I will have to find out if my drive has a cleaning brush? also I want to have all the RL drives and diskpacks cleaned and checked before I use them, as it has probably not been done in a long time, the filters where last changed in 1990! I want to start on a clean slate with them, lol. what hard to get parts should I look out for to keep the drives up and running? as the system will be doing long hours when I have built it and the CNC, lol so far I need air filters, 1 per drive now 1 or more for later, and maybe a set of spare heads, how do you tell the heads on sale are not dead? and dont worry about dust from the CNC machine, I will keep the PDP8 away from the CNC machine, in a cleaner room, and have non dec terminal by the cnc machine to use the pdp8

 

[rorypoole]

Yes, there's pictures! I'll see if I can find some time to write it up on the 4 JUL holiday. Disk packs seem to be a little more common on this side of the pond.

Unfortunately for the crashed pack, it is of little use other than as maybe wall decoration, or a clock face! We nabbed the pack shield and dust cover for another drive since they were in very good shape. They're quite useless once crashed, as a crashed pack can crash your drive, which will create more crashed packs. We decided that no pack that we even suspected of being damaged was to be mounted in any of our gear...that included things like high vibration on loading.

If you open the door covering the drive well and take a look at the slot where the heads stay, it should be pretty obvious as to whether they are parked and locked. There's a metal tab that swings over the opening for the heads, when it is up they are locked and /can not/ enter the well. If your cover solenoid is still working, you won't be able to open the door without the drive powered on. There's no need to lock the heads unless you're moving the drive a fair distance. We don't lock the heads on any of our equipment if it's just moving around the shop.

Dirty on the outside doesn't make a difference as long as it's clean on the inside! One of our filthy RL02 packs was fine on the inside and even included a copy of RT-11 4, still bootable, and no bad blocks. It doesn't look like there was any conclusive decision on whether your mystery pack is in fact a DEC-compatible RL0x pack though. Still, it would be fine to practice with.

there dont seen to be meny disk packs in the uk that I can find sadly, maybe if I go to the USA some time I could bring some back with me, I would get some funny looks from security lol

good the know you reused the good bits of the dead diskpack, and that is why I want to check all my drives and diskpacks when I get them! and the 20mb disk pack is dirty on the outside and inside sadly, and someone put an extra platter in the diskpack? I dont remember if it has rings but its scratched to death! I would hate it if good vintage hard drives and diskpack got used to make clocks ect.

are your RL02 diskpacks 12 or 16 bit?

 

[NeXT]

You're going to realize pretty quickly that spare filters have not been manufactured for a while and NOS ain't cheap. Also, you will need to get an alignment pack (oh, apparently not) if you ever need to replace heads. Again no longer manufactured and again, not cheap.
When I cleaned my packs the general rule of thumb was an open and clean workspace, a lint-free cloth and a bottle of rubbing of alcohol. Wipe the platters in a radial rotation and blast with compressed air whenever you think you need it. As mentioned, full rings of crashage means the pack is no good, major scratches are generally the same. Minor scratches and head bumps might be okay with RL drives. I know on my RK pack it's acceptable.

 

[rorypoole]

from what I have read, a standard RL02 diskpack can be used for alignment?

http://www.pdp-11.nl/peripherals/disk/rl-info.html

A special cartridge is the "Reference Disk" cartridge.
This cartridge has a clearly visible different color!
The disk is used in the alignment procedure of the RL02 drive.
Actually, it is not the alignment of the heads, because the RL01/RL02 drives use an embedded servo system.
You can align the heads with *any* normal disk cartridge.

This "Reference Disk" cartridge is an amplitude test pack to check the read amplifier, normally *not* needed.

and the blue DEC RL02K-RF Referenc Data Cartridge is $300 or £200 on ebay!!!

 

[Lou - N2MIY]

The blue pack is not needed for head alignment. Any good pack will work for head alignment. I have done head alignments on RL drives personally.

If there was a pack in that RL01 drive that you showed in the photo strapped to the hand truck AND the head restraint cover was not engaged, then the pack is trash and the heads may be also. The drive is face down in the photo and gravity is not your friend in this orientation. It was precisely this that messed up the two RL01 drives that I have. I know their history, and they were moved by people who didn't know any better. Packs were in the drives. Both packs were trashed and three of four (two pairs) of heads destroyed.

RL02 packs all have 40 sectors per track. There are no 12 and 16 bit RL packs the way there are for RK05 packs. I have taken packs that have been used on a pdp-11 and used them on an 8. As for the question a way back about RL02 on the pdp-8, yes, they were used, but even then RL02 came out in the middle of the 8A lifespan. The OS/8 handlers for the RL02 are in ther OS78 V4 release (that's where I got them from.)

Lou

 

[Qbus]

Because the packs were formatted back some time ago at the factory I always thought whenever you did the head alignment with any pack it would work with all packs, also the head positioner corrects for track accuracy, the head alignment is just a left right thing and not a front back offset like other preformatted drives.
I use to work on broadcast video tape machines back in the day and find the head alignment, servo system and care and feeding of the media to be no better or worse than those old systems. I was able to put together three or four drives just using several parts systems and the manual and have to admit that I think it’s a well thought out and designed drive. In theory the closed loop air system will keep the filter cleaner than the old open systems on the RK-05 drives and I am using filters that are all over twenty years old with no issues, but do have to say that I keep the drives in a clean aria, always keep the packs stored in a clean environment and have a habit of using the shop vac to go thru and clean the drive housing after removing a pack or inserting a new pack. I feel that if media is suffering anywhere it’s with my RX-01 and 02 drives and there media, and have to wonder what I will do when those stupid drive belts finally drop off for good.

 

[Lou - N2MIY]

Ray,

There was some discussion here a few years back about RX01/02 belts. I tried a record player belt, and it worked for a while when in continuous use, but after sitting for a while, it fell of easily.

I think the best idea that came out of the discussion was that there is a nylon reinforced flat belt from McMaster-Carr that looked like it was worth a try. I didn't buy one, but I should. It looks like 6982K61 can be ordered in 1/4" outside circle increments and is a nice N-buna coated nylon cloth flat belt.

Lou

 

[RSX11M+]

...RL02 packs all have 40 sectors per track. There are no 12 and 16 bit RL packs the way there are for RK05 packs. I have taken packs that have been used on a pdp-11 and used them on an 8. As for the question a way back about RL02 on the pdp-8, yes, they were used, but even then RL02 came out in the middle of the 8A lifespan. The OS/8 handlers for the RL02 are in ther OS78 V4 release (that's where I got them from.)

Lou

Thanks for that definitive answer. I've always wondered about 8-land specifics.

 

[Lou - N2MIY]

I've been learning a good bit about RL01/02 pack formatting lately. I've been taking apart Reinhard's pack file format for his RL02 emulator to make my own utilities to put the raw sector images used by PUTR into his format (as well as the reverse).

Lou

 

[DaveH]

The blue pack is not needed for head alignment. Any good pack will work for head alignment. I have done head alignments on RL drives personally.

If there was a pack in that RL01 drive that you showed in the photo strapped to the hand truck AND the head restraint cover was not engaged, then the pack is trash and the heads may be also. The drive is face down in the photo and gravity is not your friend in this orientation. It was precisely this that messed up the two RL01 drives that I have. I know their history, and they were moved by people who didn't know any better. Packs were in the drives. Both packs were trashed and three of four (two pairs) of heads destroyed.

Lou

Im waiting for 2 Rl02's and some packs to be shipped from Germany ( im in the UK, Scotland ), I emailed the seller some pics and instructions on how to manually open the drive, check for a cartridge and lock the heads, very glad I did now, ALL I have to worry about now is how they get treated by the shippers on there 1000 mile or so journey!!
Dave

 

[rorypoole]

now I know I will check for a cartridge and lock the heads before moving a RL drive

 

[Qbus]

As long as this big RL drive love fest is going on I have a question, what’s the best way to store the disk packs? Have seen pictures of them stacked one on top of another and that’s how I have most of the ones I own but looks like it may get hairy when stacked more than three or four high, don’t want to bump into the stack and send them crashing down. And have also seen those stacked on shelves on their sides but somehow cannot imagine that’s good for the packs unless you move them around from time to time? Don’t want the platter to warp or bend. Was thinking of building up a bunch of two RU rack shelves and having a rack bay for storage but that’s going to take up a lot of rack space but will provide a nice little shelf for each drive that gives a small amount of magnetic protection too.

 

[tradde]

As long as this big RL drive love fest is going on I have a question, what’s the best way to store the disk packs? Have seen pictures of them stacked one on top of another and that’s how I have most of the ones I own but looks like it may get hairy when stacked more than three or four high, don’t want to bump into the stack and send them crashing down. And have also seen those stacked on shelves on their sides but somehow cannot imagine that’s good for the packs unless you move them around from time to time? Don’t want the platter to warp or bend. Was thinking of building up a bunch of two RU rack shelves and having a rack bay for storage but that’s going to take up a lot of rack space but will provide a nice little shelf for each drive that gives a small amount of magnetic protection too.

I too used to wonder this as I had one of the racks to hold packs side by side. I always thought that can't be good for the packs. But as you say you don't
want to stack too many on top of each other. I think your idea might work quite well.

 

[DaveH]

Don't they suggest that you store vinyl LP's ( remember them ) upright and not flat ?, maybe the platters are less likely to warp if stored upright ?, I store my RK05 carts upright but my RL's flat ( cos no room for them upright )
Dave

 

[tradde]

Don't they suggest that you store vinyl LP's ( remember them ) upright and not flat ?, maybe the platters are less likely to warp if stored upright ?, I store my RK05 carts upright but my RL's flat ( cos no room for them upright )
Dave

Back when I had my pdp-8e it had an inbuilt RK05 holder for 4 packs that you could hide behind the bezel. I still think flat is best.
I have no LPs any more as I left them all behind when I moved. I've seen those both flat and upright. Not sure which is best.