Re: RL02 Question
> > From: Aaron Jackson
>
> > I have tried three controllers, two r/w modules and two servo
> > controllers. I'm beginning to think the drive is fine and there is a
> > problem with the RLV21 controller.
>
> Err, think you mean RLV12 QBUS controller board, right?
Woops, yes! I get mixed up with the RXV21.
> Anyway, you've already tried ("three controllers") swapping that out?
As in the logic controller inside the drive. I only have one RLV12
unfortunately. Although a friend has recently purchased one, so
hopefully I can test with that soon.
> If you have, perhaps there's a problem with a cable and/or the terminator?
>
>
> However, at this point, sub-system swapping is probably not going to be the
> best way to make progress. I think you're going to have to actually debug the
> problem; i.e. dive in and work out what's happening wrong, and why, and trace
> it back to the origin.
>
> Luckily, for this generation (and before), DEC produced wonderful technical
> manuals, which go into full detail of how the thing works. With that in hand,
> the investigative process is a lot easier; you don't have to work out how the
> thihg works by looking at the prints, it's all laid out in detail. And tech
> manuals for both the RL02 drive and RLV12 controller (EK-RLV12-TD-001) are
> available online, as are the prints (MP01282 for the RLV12).
>
> So, I'd sit down with the RLV12 tech man and read through the section on the
> drive<->controller bus (section 3.3). Then start looking at what the two are
> saying to each other on the bus, and figure out what's actually going wrong.
> From there, you'll know where the source of the problem is, and can chase it
> further.
>
> I know this sounds like it would be time-consuming, but when you think about
> the time/energy you've already put into swapping things around, chasing this
> problem, it won't be.
>
> Noel
I have been studying the technical description manual, and the
schematics in quite some detail. I think it is time I hook up a logic
analyser to the cable between the RLV12 controller and the drive to try
and see what is going on during the initial seek. I have already checked
to see if there is a 4.1MHz clock signal (there is).
Thanks,
Aaron.
Re: RL02 Question
> On Sat, Mar 31, 2018 at 11:04 AM, Noel Chiappa via cctalk <
> cctalk@classiccmp.org> wrote:
>
>> > From: Aaron Jackson
>>
>> > I have tried three controllers, two r/w modules and two servo
>> > controllers. I'm beginning to think the drive is fine and there is a
>> > problem with the RLV21 controller.
>>
>> Err, think you mean RLV12 QBUS controller board, right?
>>
>> Anyway, you've already tried ("three controllers") swapping that out?
>>
>> If you have, perhaps there's a problem with a cable and/or the terminator?
>>
>>
>> However, at this point, sub-system swapping is probably not going to be the
>> best way to make progress. I think you're going to have to actually debug
>> the
>> problem; i.e. dive in and work out what's happening wrong, and why, and
>> trace
>> it back to the origin.
>>
>>
>
>
> I remember spending a great deal of time on my RL02 problem until I finally
> figured out the problem source was the backplane. I have a UNIBUS system
> and I had a miswired DD11C. I took a DD11B and removed the NPG jumper in
> slot 2 as an experiment. It caused my RL02 to be functional, exposing the
> DD11C as the issue.
>
> I know that this will not help you directly, but given you have (probably)
> one working RL controller of the three I'd test the QBUS itself, power
> etc. Perhaps this was already discussed I am just catching up to this
> thread. I also assume this RL02 has been proven to work somewhere else
> with same cables. If not I'd try that experiment too.
>
> Bill
Thanks for the tip Bill.
I have run out ideas for debugging on the drive - everything looks fine!
I have starting turning my eyes towards my RLV12 controller. A friend
has recently bought an RLV12, so I can test it with his in the near
future.
Although, studying the technical description manual, I am not seeing
that any communication, other than 4.1MHz clock, is required when
loading the heads. I have been assuming that all of this logic is
handled by the drive only.
Thanks again,
Aaron.
Re: RL02 Question
On Sat, Mar 31, 2018 at 11:04 AM, Noel Chiappa via cctalk <
cctalk@classiccmp.org> wrote:
> > From: Aaron Jackson
>
> > I have tried three controllers, two r/w modules and two servo
> > controllers. I'm beginning to think the drive is fine and there is a
> > problem with the RLV21 controller.
>
> Err, think you mean RLV12 QBUS controller board, right?
>
> Anyway, you've already tried ("three controllers") swapping that out?
>
> If you have, perhaps there's a problem with a cable and/or the terminator?
>
>
> However, at this point, sub-system swapping is probably not going to be the
> best way to make progress. I think you're going to have to actually debug
> the
> problem; i.e. dive in and work out what's happening wrong, and why, and
> trace
> it back to the origin.
>
>
I remember spending a great deal of time on my RL02 problem until I finally
figured out the problem source was the backplane. I have a UNIBUS system
and I had a miswired DD11C. I took a DD11B and removed the NPG jumper in
slot 2 as an experiment. It caused my RL02 to be functional, exposing the
DD11C as the issue.
I know that this will not help you directly, but given you have (probably)
one working RL controller of the three I'd test the QBUS itself, power
etc. Perhaps this was already discussed I am just catching up to this
thread. I also assume this RL02 has been proven to work somewhere else
with same cables. If not I'd try that experiment too.
Bill
Re: RL02 Question
> From: Aaron Jackson
> I have tried three controllers, two r/w modules and two servo
> controllers. I'm beginning to think the drive is fine and there is a
> problem with the RLV21 controller.
Err, think you mean RLV12 QBUS controller board, right?
Anyway, you've already tried ("three controllers") swapping that out?
If you have, perhaps there's a problem with a cable and/or the terminator?
However, at this point, sub-system swapping is probably not going to be the
best way to make progress. I think you're going to have to actually debug the
problem; i.e. dive in and work out what's happening wrong, and why, and trace
it back to the origin.
Luckily, for this generation (and before), DEC produced wonderful technical
manuals, which go into full detail of how the thing works. With that in hand,
the investigative process is a lot easier; you don't have to work out how the
thihg works by looking at the prints, it's all laid out in detail. And tech
manuals for both the RL02 drive and RLV12 controller (EK-RLV12-TD-001) are
available online, as are the prints (MP01282 for the RLV12).
So, I'd sit down with the RLV12 tech man and read through the section on the
drive<->controller bus (section 3.3). Then start looking at what the two are
saying to each other on the bus, and figure out what's actually going wrong.
>From there, you'll know where the source of the problem is, and can chase it
further.
I know this sounds like it would be time-consuming, but when you think about
the time/energy you've already put into swapping things around, chasing this
problem, it won't be.
Noel
Re: RL02 Question
>>> It is also possible that a capacitor has deteriorated in the >>> timeout one-shot >> >> I was beginning to wonder if it was a capacitor > > FWIW, while restoring my 11/45 and its RK11-C, I found several failed 74LS123 > dual one-shots in various places. > > Haven’t looked at the RL02 drawings yet, but it seems it was a popular part > in DEC designs; if you have one there it might be a more likely fail than the > associated small-value timing caps which tend to be fairly robust ceramics? > > They are pretty easy to diagnose with a chipclip and a logic analyzer. > > —FritzM. Hmm, thinking about this a bit more though... I have tried three controllers, two r/w modules and two servo controllers. I'm beginning to think the drive is fine and there is a problem with the RLV21 controller. I measured the frequency of its pulses and they seemed to be within spec.
Re: RL02 Question
>>> It is also possible that a capacitor has deteriorated in the >>> timeout one-shot >> >> I was beginning to wonder if it was a capacitor > > FWIW, while restoring my 11/45 and its RK11-C, I found several failed 74LS123 > dual one-shots in various places. > > Haven’t looked at the RL02 drawings yet, but it seems it was a popular part > in DEC designs; if you have one there it might be a more likely fail than the > associated small-value timing caps which tend to be fairly robust ceramics? > > They are pretty easy to diagnose with a chipclip and a logic analyzer. > > —FritzM. Excellent to know about! Thanks
Re: RL02 Question
>> It is also possible that a capacitor has deteriorated in the >> timeout one-shot > > I was beginning to wonder if it was a capacitor FWIW, while restoring my 11/45 and its RK11-C, I found several failed 74LS123 dual one-shots in various places. Haven’t looked at the RL02 drawings yet, but it seems it was a popular part in DEC designs; if you have one there it might be a more likely fail than the associated small-value timing caps which tend to be fairly robust ceramics? They are pretty easy to diagnose with a chipclip and a logic analyzer. —FritzM.
Re: RL02 Question
> On 03/30/2018 08:26 AM, Aaron Jackson via cctalk wrote: >> >> Is it possible (or even likely) that the carriage survo is a bit sticky? >> I have a couple of these survos spare, but don't really want to mess >> with the carriage unless I have to. >> >> > It is also possible that a capacitor has deteriorated in the > timeout one-shot and is timing out too fast. > > Jon I was beginning to wonder if it was a capacitor. I ended up trying a different carriage (and servo motor) with no improvement. I'll try to figure out which cap it is and check it. Thanks! Aaron
Re: RL02 Question
On 03/30/2018 08:26 AM, Aaron Jackson via cctalk wrote: Is it possible (or even likely) that the carriage survo is a bit sticky? I have a couple of these survos spare, but don't really want to mess with the carriage unless I have to. It is also possible that a capacitor has deteriorated in the timeout one-shot and is timing out too fast. Jon
Re: RL02 Question
I think I have made some progress. I bought a new scope (TDS420A) and now I can actually measure things. My old scope was far too slow. It turns out the radial alignment was *very* off, so I have corrected this. If I disable the seek timeout error, the heads load onto track 0 and the READY lamp is stable. This is as opposed to before, where the READY lamp would flash while the heads try to remain locked onto track. So, that's good. However, the drive will not accept commands while the seek timeout error is disabled. And without SKTO the heads don't load even make it to the outer guard track. Since this is a timeout error, I am beginning to wonder if the heads are failing load fast enough. Is it possible (or even likely) that the carriage survo is a bit sticky? I have a couple of these survos spare, but don't really want to mess with the carriage unless I have to. If anyone is interested, I have screen caps of some of the alignments and checks from the manual here: http://aaronsplace.co.uk/blog/2018-03-29-rl02-possible-problem.html Thanks, Aaron. Aaron Jackson via cctalk writes: > Sorry to keep bothering you all with RL02 questions. I think I am nearly > there. > > It seems my head cleaning in a warm bath of isopropyl alcohol was a > success. I bought a tested RL02 pack and loaded it - no bad sounds, I > can extend the heads all the way. So that's good. I have supposedly a > working RL02K pack, and seemingly good heads. > > After I load a pack however, it goes into fault mode. Checking through > the test points on my scope, there is no survo burst data until I push > the heads 3-5mm further forward. So it seems to me that the heads are > not loading far enough into the pack. > > I loosened the head alignment screws to move the heads all the way > forward, tightened them back up, and tried loading the pack again. It > stopped again, 3-5mm short of track 0. So moving the heads forward > didn't seem to make any difference. > > I have tried a different control board, and read/write amplifier board, > with no success. > > Has anyone else experienced this? Is there some sensor which I am not > seeing? > > Thanks, > Aaron. -- Aaron Jackson PhD Student, Computer Vision Laboratory, Uni of Nottingham http://aaronsplace.co.uk
Re: RL02 Question
>> So, from what I can see, the drive should spin up correctly, but for >> some reason it goes into fault mode. I am right in thinking that upon >> load, the heads should continue moving forward until the first track is >> found, right? I should not have to perform a seek manually from the PDP? >> If this is not the case, perhaps there is something else wrong. > I’m not an RL02 hardware expert at all, just a daily user back in the > day. I’m reading this assuming that at all times the drive is > correctly hooked up to an RLV12 in a running PDP with the correct > cable and termination present on the drive? If it isn’t you’ll get a > fault condition instead of ready after spin up. > > A No worries, your input has been valuable, so thank you. For anyone else who might have an idea: >>> ON fault the heads are retracted and will not load till cleared. >>> Least mine behaves that way. >>> >>> Most common problems are wrong drive address, cable issues, no terminator. >>> Others include head lock not removed or the auto unlock style of >>> headlock has >>> the tab broken. >>> It seems to be hooked up correctly. When it is in the weird flashing ready state, the boot loader says "Read error" or "Device error" randomly. The heads oscillate back and forth very slightly as if it is trying to align itself better on the first track, which doesn't exist because it hasn't moved far enough into the pack. >>> IF in fault its resetting to retracted on every try. >>> If not something else is wrong. >>> I'm beginning to think the heads are bad which will be far too expensive so I may end up giving up. >>> Heads are not that expensive... However you could have a wrong pack >>> or one that has been erased and has no servo tracks. You must start with >>> a known good pack and cleaned heads. >>> >>> >>> Allison >> Well, I replaced the DOWN head and adjusted the amplitude on the r/w >> board. The drive now stays in READY without the FAULT lamp coming on, so >> this is promising. The heads load onto the first track. >> >> Without any r/w operations, should the READY light flash? Mine is >> flashing a little but not too rapidly. I am guessing this is while it >> tries to keep the heads positioned over the track. > Yes, normal read/write/seek activity causes that. > >> When I try to boot using the MXV11-BF boot roms, it says: >> > MXV-11 boot is not very chatty or informative. > >> ]] ?BOOTROM-F- DL 0 read error >> >> The alignment between the two heads looks okay also. >> >> Any ideas, anyone? > > Is the OS on it? IF RT-11 is it configured to boot from DL-nn? > IF you have OS on floppy can your do a dir of the devices it knows of? > This occurred to me just after I last replied. Silly me. Ended up booting into 2.11BSD to see if I could run disklabel on it. No such luck. I'll try RT-11 later this week. If that doesn't work I'll boot into XXDP over TU58 and give that ago. Thanks very much for your help, Allison, and others. Best, Aaron.
Re: RL02 Question
On 03/27/2018 03:22 PM, Aaron Jackson wrote: > So, from what I can see, the drive should spin up correctly, but for > some reason it goes into fault mode. I am right in thinking that upon > load, the heads should continue moving forward until the first track is > found, right? I should not have to perform a seek manually from the PDP? > If this is not the case, perhaps there is something else wrong. I’m not an RL02 hardware expert at all, just a daily user back in the day. I’m reading this assuming that at all times the drive is correctly hooked up to an RLV12 in a running PDP with the correct cable and termination present on the drive? If it isn’t you’ll get a fault condition instead of ready after spin up. A >>> No worries, your input has been valuable, so thank you. >>> >>> For anyone else who might have an idea: >> ON fault the heads are retracted and will not load till cleared. >> Least mine behaves that way. >> >> Most common problems are wrong drive address, cable issues, no terminator. >> Others include head lock not removed or the auto unlock style of >> headlock has >> the tab broken. >> >>> It seems to be hooked up correctly. When it is in the weird flashing >>> ready state, the boot loader says "Read error" or "Device error" >>> randomly. The heads oscillate back and forth very slightly as if it is >>> trying to align itself better on the first track, which doesn't exist >>> because it hasn't moved far enough into the pack. >> IF in fault its resetting to retracted on every try. >> If not something else is wrong. >> >>> I'm beginning to think the heads are bad which will be far too expensive >>> so I may end up giving up. >> Heads are not that expensive... However you could have a wrong pack >> or one that has been erased and has no servo tracks. You must start with >> a known good pack and cleaned heads. >> >> >> Allison > Well, I replaced the DOWN head and adjusted the amplitude on the r/w > board. The drive now stays in READY without the FAULT lamp coming on, so > this is promising. The heads load onto the first track. > > Without any r/w operations, should the READY light flash? Mine is > flashing a little but not too rapidly. I am guessing this is while it > tries to keep the heads positioned over the track. Yes, normal read/write/seek activity causes that. > When I try to boot using the MXV11-BF boot roms, it says: > MXV-11 boot is not very chatty or informative. > ]] ?BOOTROM-F- DL 0 read error > > The alignment between the two heads looks okay also. > > Any ideas, anyone? Is the OS on it? IF RT-11 is it configured to boot from DL-nn? IF you have OS on floppy can your do a dir of the devices it knows of? Allison > Thanks, > Aaron. >
Re: RL02 Question
So, from what I can see, the drive should spin up correctly, but for some reason it goes into fault mode. I am right in thinking that upon load, the heads should continue moving forward until the first track is found, right? I should not have to perform a seek manually from the PDP? If this is not the case, perhaps there is something else wrong. >>> I’m not an RL02 hardware expert at all, just a daily user back in the >>> day. I’m reading this assuming that at all times the drive is >>> correctly hooked up to an RLV12 in a running PDP with the correct >>> cable and termination present on the drive? If it isn’t you’ll get a >>> fault condition instead of ready after spin up. >>> >>> A >> No worries, your input has been valuable, so thank you. >> >> For anyone else who might have an idea: > ON fault the heads are retracted and will not load till cleared. > Least mine behaves that way. > > Most common problems are wrong drive address, cable issues, no terminator. > Others include head lock not removed or the auto unlock style of > headlock has > the tab broken. > >> It seems to be hooked up correctly. When it is in the weird flashing >> ready state, the boot loader says "Read error" or "Device error" >> randomly. The heads oscillate back and forth very slightly as if it is >> trying to align itself better on the first track, which doesn't exist >> because it hasn't moved far enough into the pack. > IF in fault its resetting to retracted on every try. > If not something else is wrong. > >> I'm beginning to think the heads are bad which will be far too expensive >> so I may end up giving up. > > Heads are not that expensive... However you could have a wrong pack > or one that has been erased and has no servo tracks. You must start with > a known good pack and cleaned heads. > > > Allison Well, I replaced the DOWN head and adjusted the amplitude on the r/w board. The drive now stays in READY without the FAULT lamp coming on, so this is promising. The heads load onto the first track. Without any r/w operations, should the READY light flash? Mine is flashing a little but not too rapidly. I am guessing this is while it tries to keep the heads positioned over the track. When I try to boot using the MXV11-BF boot roms, it says: ]] ?BOOTROM-F- DL 0 read error The alignment between the two heads looks okay also. Any ideas, anyone? Thanks, Aaron.
Re: RL02 Question
There's another option if you're near Manassas VA (roughly DC area):
https://www.ebay.com/itm/VINTAGE-Digital-DEC-RL02-A-Rack-Mount-PDP-11-Disk-Subsystem-Cartridge-Drive/401453950361?hash=item5d78852599:g:480AAOSwuNBZlG8W
Look at the pictures. It's in sad shape but if you look closely it looks
like the heads are locked in place for shipping. He's down to $16.49 (+199
shipping). If you can arrange local pickup it would probably be worth
risking 3 big Macs just for the parts.
Marc
On Tue, Mar 27, 2018 at 6:26 AM, Jay Jaeger via cctech <
cct...@classiccmp.org> wrote:
> My inventory indicates that I have a pair of lower ("UP") heads, part
> number 70-15637 for an RL02. (I don't have any spare "DOWN" heads as
> far as I can tell). I think they might even be new old stock, as they
> are marked "NEW" in my inventory. So maybe we could work something out.
> You might suggest a price, and we can take it from there. Once we get
> agreement, I'll open up the box they are in (in my garage) and confirm
> my inventory.
>
> JRJ
>
>
> On 3/27/2018 4:34 AM, Aaron Jackson via cctech wrote:
> >> On 03/26/2018 04:08 PM, Aaron Jackson via cctalk wrote:
> > So, from what I can see, the drive should spin up correctly, but for
> > some reason it goes into fault mode. I am right in thinking that upon
> > load, the heads should continue moving forward until the first track
> is
> > found, right? I should not have to perform a seek manually from the
> PDP?
> > If this is not the case, perhaps there is something else wrong.
> I’m not an RL02 hardware expert at all, just a daily user back in the
> day. I’m reading this assuming that at all times the drive is
> correctly hooked up to an RLV12 in a running PDP with the correct
> cable and termination present on the drive? If it isn’t you’ll get a
> fault condition instead of ready after spin up.
>
> A
> >>> No worries, your input has been valuable, so thank you.
> >>>
> >>> For anyone else who might have an idea:
> >> ON fault the heads are retracted and will not load till cleared.
> >> Least mine behaves that way.
> >>
> >> Most common problems are wrong drive address, cable issues, no
> terminator.
> >> Others include head lock not removed or the auto unlock style of
> >> headlock has
> >> the tab broken.
> >>
> >>> It seems to be hooked up correctly. When it is in the weird flashing
> >>> ready state, the boot loader says "Read error" or "Device error"
> >>> randomly. The heads oscillate back and forth very slightly as if it is
> >>> trying to align itself better on the first track, which doesn't exist
> >>> because it hasn't moved far enough into the pack.
> >> IF in fault its resetting to retracted on every try.
> >> If not something else is wrong.
> >>
> >>> I'm beginning to think the heads are bad which will be far too
> expensive
> >>> so I may end up giving up.
> >>
> >> Heads are not that expensive... However you could have a wrong pack
> >> or one that has been erased and has no servo tracks. You must start with
> >> a known good pack and cleaned heads.
> >>
> >>
> >> Allison
> >
> > Thanks for the suggestions, Allison.
> >
> > Given that the pack was tested before it was shipped, I am beginning to
> > come to the conclusion that the heads are bad. I can see the servo burst
> > data if I push the heads on a few mm further into pack, but perhaps the
> > heads produce noise which confuse the logic upon load.
> >
> > Heads are more expensive than what I'd like, from what I have seen on
> > eBay.
> >
> > I believe I have a "working" (i.e. non-crashing) down head (as in the
> > one on top). If this is head 0 (anyone know?) then I might have a chance
> > of getting it working without spending anymore money. Let's see.
> >
> > Thanks again,
> > Aaron.
> >
>
Wiring Harnesses (was: RL02 Question)
Years ago I was troubleshooting an old SuperMicro beast that was running a newspaper printing press. It kept shutting down randomly but if I hit the power button it would come up. Then randomly go down again minutes or an hour later. I spent many hours testing and swapping modules in and out of this thing from a working machine and at one point it would only power up if the front box that contained the power switch module and CDROM/floppy were out of the enclosure and separate on the bench (but still connected to the motherboard by an data/power cables). If I got a long screwdriver and earthed this front box to the main enclosure the machine would go down immediately. Power switch itself tested fine with a meter but I found there was a hidden reset swtich that wasn't in use so I desoldered and swapped them over. All problems went away and the customer practically carried me at shoulder height around the press hall. -- adrian/witchy Owner of Binary Dinosaurs, the UK's biggest home computer collection? t: @binarydinosaursf: facebook.com/binarydinosaurs w: www.binarydinosaurs.co.uk -- Forwarded message -- From: allison via cctalk <cctalk@classiccmp.org> Date: 27 March 2018 at 13:32 Subject: Re: RL02 Question To: Aaron Jackson <aa...@aaronsplace.co.uk>, "General Discussion: On-Topic and Off-Topic Posts" <cctalk@classiccmp.org> > Long short story. I got my RL02 directly through DEC while I was a > engineer there.It was a pile of parts in the back lab. The story was it was pulled > from a customersite as FS could not make it work at install. Seems despite being new > just about everything that could be swapped apparently was and no one could get it > to spin up. So I made a deal if I get it working its mine (ok, to be part of > the 11/23 in my office, which later would become mine). After assembling it and > testing it sure enough it didn't spin and would turn slowly for a few moments and quit. > Drag out the meter and start testing voltages. I found the motor starting > cap (known new) had odd voltages. A bit of ohming out later it was the crimped > faston connector at the end of the power line going to the capacitor. What > was wrong was crimped but the wire was never stripped so there was no connection. > The only thing never swapped was the power wiring harness. The pile of swapped > boards and even heads was impressive. I got the drive and word got around > that it was me that solved the riddle. I troubleshot the problem, and > didn't swap it to death.
Re: RL02 Question
My inventory indicates that I have a pair of lower ("UP") heads, part
number 70-15637 for an RL02. (I don't have any spare "DOWN" heads as
far as I can tell). I think they might even be new old stock, as they
are marked "NEW" in my inventory. So maybe we could work something out.
You might suggest a price, and we can take it from there. Once we get
agreement, I'll open up the box they are in (in my garage) and confirm
my inventory.
JRJ
On 3/27/2018 4:34 AM, Aaron Jackson via cctech wrote:
>> On 03/26/2018 04:08 PM, Aaron Jackson via cctalk wrote:
> So, from what I can see, the drive should spin up correctly, but for
> some reason it goes into fault mode. I am right in thinking that upon
> load, the heads should continue moving forward until the first track is
> found, right? I should not have to perform a seek manually from the PDP?
> If this is not the case, perhaps there is something else wrong.
I’m not an RL02 hardware expert at all, just a daily user back in the
day. I’m reading this assuming that at all times the drive is
correctly hooked up to an RLV12 in a running PDP with the correct
cable and termination present on the drive? If it isn’t you’ll get a
fault condition instead of ready after spin up.
A
>>> No worries, your input has been valuable, so thank you.
>>>
>>> For anyone else who might have an idea:
>> ON fault the heads are retracted and will not load till cleared.
>> Least mine behaves that way.
>>
>> Most common problems are wrong drive address, cable issues, no terminator.
>> Others include head lock not removed or the auto unlock style of
>> headlock has
>> the tab broken.
>>
>>> It seems to be hooked up correctly. When it is in the weird flashing
>>> ready state, the boot loader says "Read error" or "Device error"
>>> randomly. The heads oscillate back and forth very slightly as if it is
>>> trying to align itself better on the first track, which doesn't exist
>>> because it hasn't moved far enough into the pack.
>> IF in fault its resetting to retracted on every try.
>> If not something else is wrong.
>>
>>> I'm beginning to think the heads are bad which will be far too expensive
>>> so I may end up giving up.
>>
>> Heads are not that expensive... However you could have a wrong pack
>> or one that has been erased and has no servo tracks. You must start with
>> a known good pack and cleaned heads.
>>
>>
>> Allison
>
> Thanks for the suggestions, Allison.
>
> Given that the pack was tested before it was shipped, I am beginning to
> come to the conclusion that the heads are bad. I can see the servo burst
> data if I push the heads on a few mm further into pack, but perhaps the
> heads produce noise which confuse the logic upon load.
>
> Heads are more expensive than what I'd like, from what I have seen on
> eBay.
>
> I believe I have a "working" (i.e. non-crashing) down head (as in the
> one on top). If this is head 0 (anyone know?) then I might have a chance
> of getting it working without spending anymore money. Let's see.
>
> Thanks again,
> Aaron.
>
Re: RL02 Question
On 03/27/2018 05:34 AM, Aaron Jackson wrote: >> On 03/26/2018 04:08 PM, Aaron Jackson via cctalk wrote: > So, from what I can see, the drive should spin up correctly, but for > some reason it goes into fault mode. I am right in thinking that upon > load, the heads should continue moving forward until the first track is > found, right? I should not have to perform a seek manually from the PDP? > If this is not the case, perhaps there is something else wrong. I’m not an RL02 hardware expert at all, just a daily user back in the day. I’m reading this assuming that at all times the drive is correctly hooked up to an RLV12 in a running PDP with the correct cable and termination present on the drive? If it isn’t you’ll get a fault condition instead of ready after spin up. A >>> No worries, your input has been valuable, so thank you. >>> >>> For anyone else who might have an idea: >> ON fault the heads are retracted and will not load till cleared. >> Least mine behaves that way. >> >> Most common problems are wrong drive address, cable issues, no terminator. >> Others include head lock not removed or the auto unlock style of >> headlock has >> the tab broken. >> >>> It seems to be hooked up correctly. When it is in the weird flashing >>> ready state, the boot loader says "Read error" or "Device error" >>> randomly. The heads oscillate back and forth very slightly as if it is >>> trying to align itself better on the first track, which doesn't exist >>> because it hasn't moved far enough into the pack. >> IF in fault its resetting to retracted on every try. >> If not something else is wrong. >> >>> I'm beginning to think the heads are bad which will be far too expensive >>> so I may end up giving up. >> Heads are not that expensive... However you could have a wrong pack >> or one that has been erased and has no servo tracks. You must start with >> a known good pack and cleaned heads. >> >> >> Allison > Thanks for the suggestions, Allison. > > Given that the pack was tested before it was shipped, I am beginning to Did it survive shipment? Common problem. > come to the conclusion that the heads are bad. I can see the servo burst > data if I push the heads on a few mm further into pack, but perhaps the > heads produce noise which confuse the logic upon load. Not likely the heads produce noise they are passive. If there is a loose or broken wire maybe and thats easily checked with an ohm meter. However... If you push the heads in you see servo burst that suggests a alignment or servo system problem. Its supposed to seek and find the servo info. Heads fail only a few ways. Broken wires, crashed with mechanical damage, and open windings. They are remarkably simple other than mechanically precise. > Heads are more expensive than what I'd like, from what I have seen on > eBay. Cant help that. > I believe I have a "working" (i.e. non-crashing) down head (as in the > one on top). If this is head 0 (anyone know?) then I might have a chance > of getting it working without spending anymore money. Let's see. I'd have to read the RL02 service docs to remember what head is which. I' d suggest diagnosing the problem to see if its a servo/mechanical alignment issue. Long short story. I got my RL02 directly through DEC while I was a engineer there. It was a pile of parts in the back lab. The story was it was pulled from a customer site as FS could not make it work at install. Seems despite being new just about everything that could be swapped apparently was and no one could get it to spin up. So I made a deal if I get it working its mine (ok, to be part of the 11/23 in my office, which later would become mine). After assembling it and testing it sure enough it didn't spin and would turn slowly for a few moments and quit. Drag out the meter and start testing voltages. I found the motor starting cap (known new) had odd voltages. A bit of ohming out later it was the crimped faston connector at the end of the power line going to the capacitor. What was wrong was crimped but the wire was never stripped so there was no connection. The only thing never swapped was the power wiring harness. The pile of swapped boards and even heads was impressive. I got the drive and word got around that it was me that solved the riddle. I troubleshot the problem, and didn't swap it to death. Before you swap out a part that is expensive or unobtainium check to be sure its the problem. Allison
Re: RL02 Question
> On 03/26/2018 04:08 PM, Aaron Jackson via cctalk wrote: So, from what I can see, the drive should spin up correctly, but for some reason it goes into fault mode. I am right in thinking that upon load, the heads should continue moving forward until the first track is found, right? I should not have to perform a seek manually from the PDP? If this is not the case, perhaps there is something else wrong. >>> I’m not an RL02 hardware expert at all, just a daily user back in the >>> day. I’m reading this assuming that at all times the drive is >>> correctly hooked up to an RLV12 in a running PDP with the correct >>> cable and termination present on the drive? If it isn’t you’ll get a >>> fault condition instead of ready after spin up. >>> >>> A >> No worries, your input has been valuable, so thank you. >> >> For anyone else who might have an idea: > ON fault the heads are retracted and will not load till cleared. > Least mine behaves that way. > > Most common problems are wrong drive address, cable issues, no terminator. > Others include head lock not removed or the auto unlock style of > headlock has > the tab broken. > >> It seems to be hooked up correctly. When it is in the weird flashing >> ready state, the boot loader says "Read error" or "Device error" >> randomly. The heads oscillate back and forth very slightly as if it is >> trying to align itself better on the first track, which doesn't exist >> because it hasn't moved far enough into the pack. > IF in fault its resetting to retracted on every try. > If not something else is wrong. > >> I'm beginning to think the heads are bad which will be far too expensive >> so I may end up giving up. > > Heads are not that expensive... However you could have a wrong pack > or one that has been erased and has no servo tracks. You must start with > a known good pack and cleaned heads. > > > Allison Thanks for the suggestions, Allison. Given that the pack was tested before it was shipped, I am beginning to come to the conclusion that the heads are bad. I can see the servo burst data if I push the heads on a few mm further into pack, but perhaps the heads produce noise which confuse the logic upon load. Heads are more expensive than what I'd like, from what I have seen on eBay. I believe I have a "working" (i.e. non-crashing) down head (as in the one on top). If this is head 0 (anyone know?) then I might have a chance of getting it working without spending anymore money. Let's see. Thanks again, Aaron.
Re: RL02 Question
On 03/26/2018 04:08 PM, Aaron Jackson via cctalk wrote: >>> So, from what I can see, the drive should spin up correctly, but for >>> some reason it goes into fault mode. I am right in thinking that upon >>> load, the heads should continue moving forward until the first track is >>> found, right? I should not have to perform a seek manually from the PDP? >>> If this is not the case, perhaps there is something else wrong. >> I’m not an RL02 hardware expert at all, just a daily user back in the >> day. I’m reading this assuming that at all times the drive is >> correctly hooked up to an RLV12 in a running PDP with the correct >> cable and termination present on the drive? If it isn’t you’ll get a >> fault condition instead of ready after spin up. >> >> A > No worries, your input has been valuable, so thank you. > > For anyone else who might have an idea: ON fault the heads are retracted and will not load till cleared. Least mine behaves that way. Most common problems are wrong drive address, cable issues, no terminator. Others include head lock not removed or the auto unlock style of headlock has the tab broken. > It seems to be hooked up correctly. When it is in the weird flashing > ready state, the boot loader says "Read error" or "Device error" > randomly. The heads oscillate back and forth very slightly as if it is > trying to align itself better on the first track, which doesn't exist > because it hasn't moved far enough into the pack. IF in fault its resetting to retracted on every try. If not something else is wrong. > I'm beginning to think the heads are bad which will be far too expensive > so I may end up giving up. Heads are not that expensive... However you could have a wrong pack or one that has been erased and has no servo tracks. You must start with a known good pack and cleaned heads. Allison
Re: RL02 Question
>> So, from what I can see, the drive should spin up correctly, but for >> some reason it goes into fault mode. I am right in thinking that upon >> load, the heads should continue moving forward until the first track is >> found, right? I should not have to perform a seek manually from the PDP? >> If this is not the case, perhaps there is something else wrong. > > I’m not an RL02 hardware expert at all, just a daily user back in the > day. I’m reading this assuming that at all times the drive is > correctly hooked up to an RLV12 in a running PDP with the correct > cable and termination present on the drive? If it isn’t you’ll get a > fault condition instead of ready after spin up. > > A No worries, your input has been valuable, so thank you. For anyone else who might have an idea: It seems to be hooked up correctly. When it is in the weird flashing ready state, the boot loader says "Read error" or "Device error" randomly. The heads oscillate back and forth very slightly as if it is trying to align itself better on the first track, which doesn't exist because it hasn't moved far enough into the pack. I'm beginning to think the heads are bad which will be far too expensive so I may end up giving up. Thanks, Aaron.
Re: RL02 Question
> > So, from what I can see, the drive should spin up correctly, but for > some reason it goes into fault mode. I am right in thinking that upon > load, the heads should continue moving forward until the first track is > found, right? I should not have to perform a seek manually from the PDP? > If this is not the case, perhaps there is something else wrong. > I’m not an RL02 hardware expert at all, just a daily user back in the day. I’m reading this assuming that at all times the drive is correctly hooked up to an RLV12 in a running PDP with the correct cable and termination present on the drive? If it isn’t you’ll get a fault condition instead of ready after spin up. A
Re: RL02 Question
I have turned up the amplitude just a little higher than I think it should be. Instead of going into fault mode after loading a pack, the READY light flashes about quickly. With the scope hooked up I can see that it hasn't managed to find the first track yet. Not really sure what it thinks it is doing... Aaron Jackson via cctalk writes: > Hi Andrea, > > Thanks for your suggestions. > > Checking the amplified output from the r/w heads is one of the first > things I did. The voltages are within normal range, but only after I > push the head a bit further into the pack. > > Although, I did not set the jumper to try the other head (I suppose I > was always looking at head 0), so I've just tried this now. There does > indeed appear to be servo burst data coming from both heads once I've > manually loaded them fully. So I am not sure if this is the problem. I'm > really hoping that the pack is not bad since I paid for a tested pack. > > I also checked the sector transducer output last night. The individual > waves (i.e. from trough to peak) seem to be twice as fast, but the > timings between two peaks is correct. > > The survo busts are correctly aligned with the sector pulses. > > So, from what I can see, the drive should spin up correctly, but for > some reason it goes into fault mode. I am right in thinking that upon > load, the heads should continue moving forward until the first track is > found, right? I should not have to perform a seek manually from the PDP? > If this is not the case, perhaps there is something else wrong. > > Thanks again for your input, > Aaron. > > > > shad via cctalk writes: > >> Hello, >> I'm not an absolute expert, but I successfully fixed a couple of RL02 in >> the past. >> Adjustment to the head is only useful for azimuth, I think. The radial >> position will be adjusted continuously using the servo tracks, so there's >> no absolute position adjustment at all. >> If the drive fails during spinup, I would check at least the following: >> - the presence of spindle sector signal after digital conversion of pulses >> from analog signal coming from the pickup. >> - having disabled the servo linear motor (there's some jumper to setup, >> check the maintenance manual), perform the motor spinup, then load slowly >> the heads on the disk by hand, until you find the servo tracks. >> - with an oscilloscope check the presence of analog signal of the servo >> tracks on both heads, and it's digital counterpart after amplification and >> threshold detection (expected level values in the manual). If you see >> something strange, e.g missing or too short pulses, try to adjust the gain >> with the trimmer on the head board >> - enable again the servo, then load again >> >> My 2 cents. >> Andrea -- Aaron Jackson PhD Student, Computer Vision Laboratory, Uni of Nottingham http://aaronsplace.co.uk
Re: RL02 Question
Hi Andrea, Thanks for your suggestions. Checking the amplified output from the r/w heads is one of the first things I did. The voltages are within normal range, but only after I push the head a bit further into the pack. Although, I did not set the jumper to try the other head (I suppose I was always looking at head 0), so I've just tried this now. There does indeed appear to be servo burst data coming from both heads once I've manually loaded them fully. So I am not sure if this is the problem. I'm really hoping that the pack is not bad since I paid for a tested pack. I also checked the sector transducer output last night. The individual waves (i.e. from trough to peak) seem to be twice as fast, but the timings between two peaks is correct. The survo busts are correctly aligned with the sector pulses. So, from what I can see, the drive should spin up correctly, but for some reason it goes into fault mode. I am right in thinking that upon load, the heads should continue moving forward until the first track is found, right? I should not have to perform a seek manually from the PDP? If this is not the case, perhaps there is something else wrong. Thanks again for your input, Aaron. shad via cctalk writes: > Hello, > I'm not an absolute expert, but I successfully fixed a couple of RL02 in > the past. > Adjustment to the head is only useful for azimuth, I think. The radial > position will be adjusted continuously using the servo tracks, so there's > no absolute position adjustment at all. > If the drive fails during spinup, I would check at least the following: > - the presence of spindle sector signal after digital conversion of pulses > from analog signal coming from the pickup. > - having disabled the servo linear motor (there's some jumper to setup, > check the maintenance manual), perform the motor spinup, then load slowly > the heads on the disk by hand, until you find the servo tracks. > - with an oscilloscope check the presence of analog signal of the servo > tracks on both heads, and it's digital counterpart after amplification and > threshold detection (expected level values in the manual). If you see > something strange, e.g missing or too short pulses, try to adjust the gain > with the trimmer on the head board > - enable again the servo, then load again > > My 2 cents. > Andrea -- Aaron Jackson PhD Student, Computer Vision Laboratory, Uni of Nottingham http://aaronsplace.co.uk
Re: RL02 Question
Hello, I'm not an absolute expert, but I successfully fixed a couple of RL02 in the past. Adjustment to the head is only useful for azimuth, I think. The radial position will be adjusted continuously using the servo tracks, so there's no absolute position adjustment at all. If the drive fails during spinup, I would check at least the following: - the presence of spindle sector signal after digital conversion of pulses from analog signal coming from the pickup. - having disabled the servo linear motor (there's some jumper to setup, check the maintenance manual), perform the motor spinup, then load slowly the heads on the disk by hand, until you find the servo tracks. - with an oscilloscope check the presence of analog signal of the servo tracks on both heads, and it's digital counterpart after amplification and threshold detection (expected level values in the manual). If you see something strange, e.g missing or too short pulses, try to adjust the gain with the trimmer on the head board - enable again the servo, then load again My 2 cents. Andrea
RL02 Question
Sorry to keep bothering you all with RL02 questions. I think I am nearly there. It seems my head cleaning in a warm bath of isopropyl alcohol was a success. I bought a tested RL02 pack and loaded it - no bad sounds, I can extend the heads all the way. So that's good. I have supposedly a working RL02K pack, and seemingly good heads. After I load a pack however, it goes into fault mode. Checking through the test points on my scope, there is no survo burst data until I push the heads 3-5mm further forward. So it seems to me that the heads are not loading far enough into the pack. I loosened the head alignment screws to move the heads all the way forward, tightened them back up, and tried loading the pack again. It stopped again, 3-5mm short of track 0. So moving the heads forward didn't seem to make any difference. I have tried a different control board, and read/write amplifier board, with no success. Has anyone else experienced this? Is there some sensor which I am not seeing? Thanks, Aaron. -- Aaron Jackson PhD Student, Computer Vision Laboratory, Uni of Nottingham http://aaronsplace.co.uk
