2 Dec
2002
2 Dec
'02
8:04 p.m.
I just received an RL02K-DC disk cartridge that I won on Ebay. It looks
the same as all my other cartridges, and the shock indicator is still
white.
When I put the cartridge in either of my drives, it spins up for a while
then the fault light comes on. This does not happen with any of the
other RL02 cartridges I have.
I can see no difference between this cartridge and any of the others,
and it seems to take no less force to turn by hand.
I'm wondering what I could be missing. Any help would be greatly
appreciated.
--
Christopher L McNabb
Operating Systems Analyst Email: cmcnabb(a)4mcnabb.net
Virginia Tech ICBM: 37.1356N 80.4272N
GMRS: WPSR255 ARS: N2UX Grid Sq: EM97SD
2 Dec
2 Dec
8:22 p.m.
On Mon, 2 Dec 2002, Christopher McNabb wrote:
I just received an RL02K-DC disk cartridge that I won
on Ebay. It looks
the same as all my other cartridges, and the shock indicator is still
white.
Not been used as a Frisbee, then.... this is good.
When I put the cartridge in either of my drives, it spins up for a while
then the fault light comes on. This does not happen with any of the
other RL02 cartridges I have.
How long is a 'while'?
Is a 'while' the same each time, or is it a variable amount of 'while'?
Do your working disks function subsequently in the same drives, AFTER
you try the bad one?
Is there info on the disk you want, or just the platter itself? If the
latter case, is there enough time to INIT it before it faults?
What machine model and hardware config are you using? What OS and
version are you running? Do you have the DEC diagnostics?
I can see no difference between this cartridge and any
of the others,
and it seems to take no less force to turn by hand.
Irrelevant and potentially dangerous test - Dont Do This!! The RL02
will tell you if there is something wrong with the disk, as it seems to be
doing now.
Do you know how to clean the heads on your drives? Even a minor
headcrash leaves gunk on the head surfaces, and renders the disk platter
itself unusable in most cases... be careful!
I'm sure that others will also amplify these questions before any
intelligent reaponse can be given. In the meantime, I'd suggest not
trying to re-run the offending disk until this gets sorted out.
Cheers
John
PS: How much didja pay for it? Just curious...
8:42 p.m.
On Mon, 2002-12-02 at 21:24, John Lawson wrote:
On Mon, 2 Dec 2002, Christopher McNabb wrote:
Probably between 30 and 45 seconds. I haven't timed it.
When I put the cartridge in either of my drives,
it spins up for a while
then the fault light comes on. This does not happen with any of the
other RL02 cartridges I have.
How long is a 'while'?
Is a 'while' the same each time, or is it a variable amount of
'while'?
It is always the same. I think that maybe the drive thinks the disk is
not coming up to speed fast enough.
Do your working disks function subsequently in the
same drives, AFTER
you try the bad one?
Yes, once I cycle power to the drive to clear the fault light. I wish I
knew a cleaner way to reset the fault light.
Is there info on the disk you want, or just the
platter itself? If the
latter case, is there enough time to INIT it before it faults?
The label claims that the disk holds 'Stand-alone Forth', which may be
interesting. The ready light never comes on, just the fault light, so I
don't think I could INIT it if I wanted to.
What machine model and hardware config are you
using? What OS and
version are you running? Do you have the DEC diagnostics?
The machine is a PDP-11/24 with one RA-80 and 2 RL-02 disks, 1024 KB
RAM, FPU, EIS, DZ11A. Running RSTS 9.2
PS: How much didja pay for it? Just curious...
$9.95 plus $12.50 shipping.
--
Christopher L McNabb
Operating Systems Analyst Email: cmcnabb(a)4mcnabb.net
Virginia Tech ICBM: 37.1356N 80.4272N
GMRS: WPSR255 ARS: N2UX Grid Sq: EM97SD
9 p.m.
On Mon, 2 Dec 2002, Christopher McNabb wrote:
I'm not sure what the hardware timeout for bad Tachometer signals is...
but it sure sounds like either the tach segment is munged somewhow (The
ring on the bottome of the platter hub with the slits cut in it) or that
the data on the platter is damaged, or that it was not written on a DEC
system. The packs were used on a number of different systems.
Re-boot the computer. At least my 11/44 clears an RL02 fault on re-boot.
Yup, that's true: if it never comes into ready, little else can be done.
Do you have any way of knowing what actual System recorded the disk? If
it wasn't a DEC OS, you might have a problem. At the last VCF, I tried to
read two packs that someone had, to see what was on them, and the same
thing happened. (PDP11/44, RSX11M)
Not bad, considering what they cost new (around $200).
With deference to further incoming opinions, I would think perhaps the
data format is completely incompatible, and the drive can't 'find' the
correct bit pattern, and thus it pukes. Tony Duell is familiar with the
internal operation of the RL02, and perhpas he can shed better light.
Cheers
John
How long is a 'while'?
Probably between 30 and 45 seconds. I haven't timed it.
Is a 'while' the same each time, or is it a variable amount of
'while'?
It is always the same. I think that maybe the drive thinks the disk is
not coming up to speed fast enough.
Do your
working disks function subsequently in the same drives, AFTER
you try the bad one?
Yes, once I cycle power to the drive to clear the fault light. I wish I
knew a cleaner way to reset the fault light. Is there info on the disk you want, or just the
platter itself? If the
latter case, is there enough time to INIT it before it faults?
The label claims that the disk holds 'Stand-alone Forth', which may be
interesting. The ready light never comes on, just the fault light, so I
don't think I could INIT it if I wanted to.
PS: How much didja pay for it? Just curious...
$9.95 plus $12.50 shipping.
9:08 p.m.
On Mon, 2002-12-02 at 22:01, John Lawson wrote:
On Mon, 2 Dec 2002, Christopher McNabb wrote:
With deference to further incoming opinions, I would think perhaps the
data format is completely incompatible, and the drive can't 'find' the
correct bit pattern, and thus it pukes. Tony Duell is familiar with the
internal operation of the RL02, and perhpas he can shed better light.
The label says it is Stand Alone Forth-11. That said, I know I'm guilty
of not changing disk labels after overwriting data, so it is entirely
possible that something else is on the disk..
--
Christopher L McNabb
Operating Systems Analyst Email: cmcnabb(a)4mcnabb.net
Virginia Tech ICBM: 37.1356N 80.4272N
GMRS: WPSR255 ARS: N2UX Grid Sq: EM97SD
10:42 p.m.
Christopher McNabb wrote:
On Mon, 2002-12-02 at 22:01, John Lawson wrote:
Forth is known for not using a disk file system
and reading/writing directly to disk. Forth is
one place you need to be very carefull reading the
docs.
On Mon, 2 Dec 2002, Christopher McNabb wrote:
With deference to further incoming opinions, I
would think perhaps the
data format is completely incompatible, and the drive can't 'find' the
correct bit pattern, and thus it pukes. Tony Duell is familiar with the
internal operation of the RL02, and perhpas he can shed better light.
The label says it is Stand Alone Forth-11. That said, I know I'm guilty
of not changing disk labels after overwriting data, so it is entirely
possible that something else is on the disk..
10:45 p.m.
On Mon, 2 Dec 2002, John Lawson wrote:
I'm not sure what the hardware timeout for bad
Tachometer signals is...
but it sure sounds like either the tach segment is munged somewhow (The
ring on the bottome of the platter hub with the slits cut in it) or that
the data on the platter is damaged, or that it was not written on a DEC
system. The packs were used on a number of different systems.
I'd go for possibly a dislodged "tach magnet" (really they mark sectors
IIRC). I'd _really_ doubt it's got anything to do with what's written on
the pack (see below).
With deference to further incoming opinions, I would
think perhaps the
data format is completely incompatible, and the drive can't 'find' the
correct bit pattern, and thus it pukes. Tony Duell is familiar with the
internal operation of the RL02, and perhpas he can shed better light.
While I'm not Tony, I spent some time last year slaving over the RL02 (and
RLV12, RL8A) printsets, and I can tell you that the drive _doesn't_ care
what data is recorded on the disk. Fundamentally, the RL01/02 is a
fairly 'dumb' drive. Other than the sector marking magnets on the hub of
the disk, the drive is fairly undiscriminating. The only real circuits
between the read/write head and the ports on the back of the drive are
read and write amps (and write gate, etc).
A good check would be to listen for the heads to load into the pack. If
they're not loading, then there's no way that the data can be the source
of the problem.
Pat
--
Purdue Universtiy ITAP/RCS
Information Technology at Purdue
Research Computing and Storage
http://www-rcd.cc.purdue.edu
3 Dec
3 Dec
5:19 a.m.
On Mon, 2002-12-02 at 23:50, Patrick Finnegan wrote:
I'd go for possibly a dislodged "tach
magnet" (really they mark sectors
IIRC). I'd _really_ doubt it's got anything to do with what's written on
the pack (see below).
Where should the "tach magnet" be?
A good check would be to listen for the heads to load
into the pack. If
they're not loading, then there's no way that the data can be the source
of the problem.
I don't believe the heads are loading. At least, I can't hear them do
so.
--
Christopher L McNabb
Operating Systems Analyst Email: cmcnabb(a)4mcnabb.net
Virginia Tech ICBM: 37.1356N 80.4272N
GMRS: WPSR255 ARS: N2UX Grid Sq: EM97SD
6:09 p.m.
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6:42 p.m.
Tony,
Do RL02's have a servo platter? I recall working with 300 and 600MB
multi-platter packs, on which one entire surface was reserved for "servo" to
help the head actuator establish track-to-track position. On many occasions
I'd see CDC drives load and then immediately retract heads and abort to
fault state if it couldn't read the servo platter, the net of which was
usually a 10-platter doorstop with a pretty plastic cover. ;-)
Patrick
-----Original Message-----
From: cctalk-admin(a)classiccmp.org [mailto:cctalk-admin@classiccmp.org]On
Behalf Of Tony Duell
Sent: Tuesday, December 03, 2002 4:03 PM
To: cctalk(a)classiccmp.org
Subject: Re: RL02 Disk Cartridge Problems
While I'm not Tony, I spent some time last
year slaving over
the RL02 (and
RLV12, RL8A) printsets, and I can tell you that
the drive _doesn't_ care
what data is recorded on the disk. Fundamentally, the RL01/02 is a
fairly 'dumb' drive. Other than the sector marking magnets on the hub of
the disk, the drive is fairly undiscriminating. The only real circuits
between the read/write head and the ports on the back of the drive are
read and write amps (and write gate, etc).
Be careful. The drive most certainly uses the servo signals recorded
between the sectors. These are read by the normal heads/read ampifiers,
and then passed to the drive logic board. If those are missing/mangled,
the heads can't go on-track.
But he drive most certainly doesn't try to do anything with the user
data, including the headers and checksums. That's all handled by the
controller.
A good check would be to listen for the heads to
load into the pack. If
they're not loading, then there's no way that the data can be the source
of the problem.
Agreed. Let's see what those heads are doing.
-tony
4 Dec
4 Dec
3:57 p.m.
--- Patrick Rigney <patrick(a)evocative.com> wrote:
Tony,
Do RL02's have a servo platter?
No. The RL01 and RL02 drives use embedded servo.
If the heads won't load, I would also suspect that the RPM isn't
detected within limits. I didn't know there was an active component
in the cartridge, but if it were missing or dislodged, that could
account for the symptoms.
I know more about the innards of the RK05, and it uses a cut aluminum
hub and a hall sensor to detect sectors - the cartridge is passive.
The gap in the hub rim triggers the hall sensor and a new sector
begins. I guess the RL01/RL02 must have a similar mechanism, but
with magnets, not gaps.
-ethan
__________________________________________________
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7:18 p.m.
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3 Dec
3 Dec
6:45 p.m.
New subject: Latest Rescue
I just returned from rescuing a ca 1980 Wang VS-90 from a factory in
Yorklyn, Delaware. The 90 is a fairly rare single processor version of
the big VS-100, and was replaced with the VS-85 at an early date because it
was not a very popular model, although a number were used by the US Govt
in the island territories, often, I was told, with huge battery banks
because the power supply was very undependable.
This VS-90 is attributed to commerce raider Victor Posner who at one point
owned 64 Wang mainframes. Rather a nice system.
Rhode Island Computer Museum, Inc.
Shady Lea, Rhode Island
"Casta est quam nemo rogavit."
- Ovid
8:23 p.m.
New subject: Latest Rescue
I just returned from rescuing a ca 1980 Wang VS-90
from a factory in
Yorklyn, Delaware.
Excellent. It is nice to know that something scarce
that is non-DEC/HP/DG/Sun/SGI/IBM is being saved...
This VS-90 is attributed to commerce raider Victor
Posner who at one point
owned 64 Wang mainframes. Rather a nice system.
OK, I think you need to tell more.
William Donzelli
aw288(a)osfn.org
11:44 p.m.
New subject: Latest Rescue
I just
returned from rescuing a ca 1980 Wang VS-90 from a factory in
Yorklyn, Delaware.
Excellent. It is nice to know that something scarce
that is non-DEC/HP/DG/Sun/SGI/IBM is being saved...
This VS-90 is attributed to commerce raider
Victor Posner who at one point
owned 64 Wang mainframes. Rather a nice system.
OK, I think you need to tell more.
William Donzelli
aw288(a)osfn.org
4 Dec
4 Dec
8:43 a.m.
New subject: Latest Rescue
I'm going to try to get some shots as we unload today. There are 5
2265's and 2 2209's as well as some 5570 series printers. (The infamous
DataProducts B600's.
On Tue, 3 Dec 2002, Wayne M. Smith wrote:
And show more - how about a picture or two?
M. K. Peirce
Rhode Island Computer Museum, Inc.
Shady Lea, Rhode Island
"Casta est quam nemo rogavit."
- Ovid
I just returned from rescuing a ca 1980 Wang VS-90
from a factory in
Yorklyn, Delaware.
Excellent. It is nice to know that something scarce
that is non-DEC/HP/DG/Sun/SGI/IBM is being saved...
This VS-90 is attributed to commerce raider
Victor Posner who at one point
owned 64 Wang mainframes. Rather a nice system.
OK, I think you need to tell more.
William Donzelli
aw288(a)osfn.org
3 Dec
3 Dec
6:08 p.m.
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6:07 p.m.
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7:07 p.m.
On Tue, 2002-12-03 at 18:52, Tony Duell wrote:
Spin up this pack. Do the heads ever move? If so, what do they do.
Yup, the heads move in, sit for about a second, then the drive faults.
My guess at this point is that the disk was bulk erased or the servo
signals were removed in some other fashion.. :-(
The question is, Is there any way to get the servo signals re-recorded,
or have I just spent 9.95 plus shipping on a "Piece of Artwork"
--
Christopher L McNabb
Operating Systems Analyst Email: cmcnabb(a)4mcnabb.net
Virginia Tech ICBM: 37.1356N 80.4272N
GMRS: WPSR255 ARS: N2UX Grid Sq: EM97SD
7:17 p.m.
The question is, Is there any way to get the servo
signals re-recorded,
or have I just spent 9.95 plus shipping on a "Piece of Artwork"
In general, if you have a disk with blown servo signals, you're screwed.
Writing the servo signals requires uncommon and very expensive equipment.
7:29 p.m.
I am wondering if an accurate and technical description of the RL02
servo tracks and (maybe) a description of how they are actually applied
exists anywhere... the ultimate object being possibly modifying an
existing RL02 drive to write these tracks.
Anyone with any concrete info regarding this?
I modified a 5 1/4" floppy to write the special 'spiral' tracks used by
an old music sampler when the parent company went out of business... the
same problem existed as above, but in a different manifestation.
If the writing heads width is the same, I am wondering if a drive
couldn't be modified to write servo tracks....?
Cheers
John
4 Dec
4 Dec
9:32 a.m.
New subject: HP/Dec/Sun... vs Oddballs
Hi,
I have a Wicat 68000 class mini with manuals, Eagle SMD
drive(s) and Pertec tape controller from about 1982 that I've
kept for three years because of its magtape support. Over that
time I've built up DEC systems to do the same function. Support
for SMD is still missing, but that's OK. This is a nice working
system with at least 10X the power of a PC of that era, and a
great workable OS. With space at a premium for me (this is a
one-rack system), I'm letting everyone here know that I intend to
toss the system in 30 days if there are no takers. A pretty
horrifying thought to some, but this represents practicality on my
part.
If anyone wants to be a taker or knows any others, even worldwide,
who might be interested, drop me a note.
I will be taking no action on this until well after 01-Jan, so
everyone can have happy holidays.
John A.
11:20 a.m.
New subject: HP/Dec/Sun... vs Oddballs
On Wed, 4 Dec 2002, John Allain wrote:
I have a Wicat 68000 class mini with manuals, Eagle
SMD
drive(s) and Pertec tape controller from about 1982 that I've
kept for three years because of its magtape support. Over that
time I've built up DEC systems to do the same function. Support
for SMD is still missing, but that's OK. This is a nice working
system with at least 10X the power of a PC of that era, and a
great workable OS. With space at a premium for me (this is a
one-rack system), I'm letting everyone here know that I intend to
toss the system in 30 days if there are no takers. A pretty
horrifying thought to some, but this represents practicality on my
part.
How heavy is it?
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
* Old computing resources for business and academia at www.VintageTech.com *
2:02 p.m.
New subject: HP/Dec/Sun... vs Oddballs
> I have a Wicat 68000 class ... (this is a one-rack
system)...
How heavy is it?
This is all IIRC, but should be right since I hand carried it all at
one time. System unit (real lightweight design for its 19" size)
<70 lbs; Power supply (small so easy to carry) ~30 lbs; Fujitsu
Eagle ~125 lbs; fan box <20 lbs.
John A.
7:22 p.m.
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5 Dec
5 Dec
4:37 p.m.
Tony Duell wrote:
If they move almost all the way to the spindle, then
it sounds like the
pack has been bulk-erased and the drive can't find any servo information :-(
I can confirm that this is what happened on a drive with a dead read
amplifier. No read signals, so no servo bursts, and the head went
all the way in -- at a slightly alarming speed, when I had my fingers
close to it :)
We fitted a new op-amp chip in the read amplifier, and it all worked
again.
--
John Honniball
coredump(a)gifford.co.uk
9 Dec
9 Dec
7:12 p.m.
New subject: RL02 Disk Cartridge Problems - why that particular pack is junk
The RL01/RL02 manual that I won on E-Bay last week arrived in the mail
today. It has quite a good write up on the drive formatting, including
the structure of each sector.
The sector format is as follows:
Sector Pulse: 62.5 microseconds, generated by slots on bottom of disk
hub
Header (Described Below)
Data 128 16 bit words, or
256 8 bit bytes, or
170 12 bit words
The sector header occurs after the the sector pulse and contains the
sector number, track number, and head number of the sector in the
following format:
Preamble: 47 Zero Bits followed by a 1 bit
Address: 16 bits - Sector: 6 bits
Head: 1 bit
cylinder:9 bits
Zeroes: 16 bits of zeros
CRC: 16 bits generated by CRC logic when data is written to the sector
Postamble: 16 zero bits
There is also a "guard track" on each side of the data track,whose
purpose is to cause the head to go back to the center of the data track
should it drift.
When a drive is told to seek to a particular sector, it reads the
factory written sector header to determine if it is the correct sector.
If the drive can not find this info quickly enough, it will fault.
Internal drive circuitry prevents the drive from writing to any part of
the header (except the CRC word).
It seems to me that to correctly format one of these disks after a bulk
erasure, you would have to be able to do the following:
1. Correctly position the head - probably the easiest part
2. Write the correct sector header, including addressing
3. Write the guard tracks ( I bet this is the most difficult)
4. Make sure all the header data gets written to the disk in the
required 62.5 milliseconds (one sector requires 625 milliseconds to pass
under the head, the data part of the sector takes 500 milliseconds, the
servo pulse takes 62.5 milliseconds.
5. Create the "Bad Block" file at the end of the disk.
So, looking at the above, I can see where it would very difficult to
format one of these guys using a stock RL01/RL02 drive, even modified.
It may be possible, however, to do it with another manufacturer's 5440
type disk drive, but I'm just guessing.
--
Christopher L McNabb
Operating Systems Analyst Email: cmcnabb(a)4mcnabb.net
Virginia Tech ICBM: 37.1356N 80.4272N
GMRS: WPSR255 ARS: N2UX Grid Sq: EM97SD
10 Dec
10 Dec
6:56 p.m.
New subject: RL02 Disk Cartridge Problems - why that particular pack is junk
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7:35 p.m.
New subject: RL02 Disk Cartridge Problems - why that particular pack is junk
On Tue, 2002-12-10 at 19:07, Tony Duell wrote:
According to the manual I have, CSR bits 10 and 12 will be set if the
drive does not locate the correct sector within 200ms. This would seem
to imply that the header IS read and checked. If not by the drive
itself, then by the controller. Perhaps I should speak of the
Drive/Controller system?
At any rate, I don't believe it is worth the effort to attempt to
reformat a bulk erased disk.
--
Christopher L McNabb
Operating Systems Analyst Email: cmcnabb(a)4mcnabb.net
Virginia Tech ICBM: 37.1356N 80.4272N
GMRS: WPSR255 ARS: N2UX Grid Sq: EM97SD
Is there? I was under the impression there were guard bands on the very
inside and very outside of the disk (used when the heads are loading,
etc). Bot not between each pair of data tracks.
The manual I'm looking at says the guard tracks are on either side of
the data area. I read this to be the sector's data area, but I can see
where it could also be the disk's data area.
When a drive is told to seek to a particular sector, it reads the
factory written sector header to determine if it is the correct sector.
If the drive can not find this info quickly enough, it will fault.
Sorry, but no. The drive doesn't check the headers at all. I've been
through the schematics and there's nothing that will look at digital
data on the disk. It will fault if it can't find the servo signals, though.
11 Dec
11 Dec
4:50 p.m.
New subject: RL02 Disk Cartridge Problems - why that particular pack is junk
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2 Dec
2 Dec
8:41 p.m.
Christopher McNabb wrote:
I just received an RL02K-DC disk cartridge that I won
on Ebay. It looks
the same as all my other cartridges, and the shock indicator is still
white.
When I put the cartridge in either of my drives, it spins up for a while
then the fault light comes on. This does not happen with any of the
other RL02 cartridges I have.
I can see no difference between this cartridge and any of the others,
and it seems to take no less force to turn by hand.
I'm wondering what I could be missing. Any help would be greatly
appreciated.
Been a while since I used these drives. I know that if debris got into the
grooves cut into the sector ring of an RK05 .. that would cause problems
-nick
8062
days inactive
8071
days old
31 comments
16 participants
participants (16)
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ard＠p850ug1.demon.co.uk -
at258＠osfn.org -
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bfranchuk＠jetnet.ab.ca -
cmcnabb＠4mcnabb.net -
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jpl15＠panix.com -
jss＠subatomix.com -
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pat＠purdueriots.com -
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