14 Feb
2019
14 Feb
'19
7:34 p.m.
I got a laugh out of this anecdote. Of course, folks heard me chuckle
and I tried to share the joke but.... Way too geeky for public
consumption.
Back in 2000-ish, I was upgrading my DG MV4000/dc to 8mb so as to be
able to run the snazzy AOS/VS II tapes I'd got along with the 9 track
drive I hacked onto the machine...
The install would start and then bomb at a certain point every time. I
decided to work the machine hard and then pull the board and give a
good SNIFF. This is a 15x15 inch board populated with 256kx1 drams.
The time in the machine got the board cooking nicely, and when I
smelled a certain charred smell in the vicinity of a 74ls04, I knew it
was that magic black smoke. I pulled a 74HCT04 from a known-good isa
card, socketed the spot and viola! Working 8mb board. It isn't
ALLWAYS the most expensive chip, thank God, and sometimes even us not-
as-bright guys come off with a win.
I really enjoy reading this list even though I don't contribute all
that often or anything of much value. It is a pleasure to watch you
guys work.
Jeff
On Thu, 2019-02-14 at 12:00 -0600, cctalk-request at classiccmp.org wrote:
Re: PDP-11/45 RSTS/E boot problem
When our 11/45 failed in the MMU in 1975, my classmate
Josh Rosen
traced the failing path on the schematics. When Jim Newport the field
service engineer showed up, Josh described the diagnostics result that
pointed at the failed path, and added "This is the failed chip"
(pointing to one particular chip.
Jim asked "Why that one?" Josh answered "because that is the most
expensive chip".
It turned out he was right.
paul
15 Feb
15 Feb
3:06 a.m.
On Fri, 15 Feb 2019 at 04:34, Jeffrey S. Worley via cctalk
<cctalk at classiccmp.org> wrote:
The install would start and then bomb at a certain point every time. I
decided to work the machine hard and then pull the board and give a
good SNIFF.
Got a nose for a hardware fault, eh? ;-)
And some of my younger colleagues thought it was strange that I could
predict hard disk failures from the running noises they made, and
later than that, whether WinNT's bus-mastering DMA-mode disk
controller device driver was installed from the sound of the disk
accesses while the machine booted.
BTW, Jeff, Gmail bottom-quotes just fine. I'm using the web interface
right now. Just hit Ctrl-A, trim as needed and move the cursor. Yes,
it's a pain on mobile, so I try not to answer on mobiles!
--
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5:59 a.m.
On Feb 15, 2019, at 6:06 AM, Liam Proven via cctalk
<cctalk at classiccmp.org> wrote:
On Fri, 15 Feb 2019 at 04:34, Jeffrey S. Worley via cctalk
<cctalk at classiccmp.org> wrote:
Speaking of sounds made by machines, there is a famous security paper from a few years ago
in which researchers read the encryption keys out of smartphones by listening to the
sounds made by the device while it was execution the crypto algorithms.
These hardware wizard stories remind me of a legendary repair wizard, non-computer
industrial devices I think. He was called in to fix a tricky problem at the customer
site. Studied it for a while, took out a small hammer, whacked the device at some spot,
and reported "fixed". He then sent in a bill for $500.
Customer challenged that with a demand to itemize the work. The itemized bill came back
like this:
1. Applying impact to the device: $5
2. Knowing where and how to apply the impact: $495
paul
The install would start and then bomb at a certain point every time. I
decided to work the machine hard and then pull the board and give a
good SNIFF.
Got a nose for a hardware fault, eh? ;-)
And some of my younger colleagues thought it was strange that I could
predict hard disk failures from the running noises they made, and
later than that, whether WinNT's bus-mastering DMA-mode disk
controller device driver was installed from the sound of the disk
accesses while the machine booted.
7:29 a.m.
On Fri, 15 Feb 2019 at 14:59, Paul Koning <paulkoning at comcast.net> wrote:
Speaking of sounds made by machines, there is a famous security paper from a few years
ago in which researchers read the encryption keys out of smartphones by listening to the
sounds made by the device while it was execution the crypto algorithms.
... wow.
These hardware wizard stories remind me of a legendary
repair wizard, non-computer industrial devices I think. He was called in to fix a tricky
problem at the customer site. Studied it for a while, took out a small hammer, whacked
the device at some spot, and reported "fixed". He then sent in a bill for
$500.
Customer challenged that with a demand to itemize the work. The itemized bill came back
like this:
1. Applying impact to the device: $5
2. Knowing where and how to apply the impact: $495
110 years old, and still apt.
https://quoteinvestigator.com/2017/03/06/tap/
I first encountered it in the form of one of the AI Koans. I guess
these are probably familiar to all here, but in case:
http://people.cs.uchicago.edu/~wiseman/humor/ai-koans.html
--
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4 p.m.
Liam Proven wrote:
And some of my younger colleagues thought it was strange that I could
predict hard disk failures from the running noises they made, and
later than that, whether WinNT's bus-mastering DMA-mode disk
controller device driver was installed from the sound of the disk
accesses while the machine booted.
The little 8GB SCA system disk in my Alphaserver 800 started making
awful bloodcurdling clattering noises a few years ago. The first time
I heard it, I was convinced that the works were splattered all over the
inside of the HDA casing and the machine was only continuing to run
because of what was left in the disk cache or something like that. I
started running a backup in case I might be able to salvage some part of
the contents. Despite several more heartstopping clunks and clatters
while the backup was running, it ran to completion, with no errors logged
to my complete surprise. I ran an ANALYZE /DISK /READ which attempts to
read all blocks on the disk that are allocated to files. Again, several
more awful clanks and clatters but it completed with no errors. I lined
up a replacement disk for it but I was curious to see how exactly it
was going to fail so I decided to keep on using it for a while to see
what happens. Days turned into weeks, weeks into months and months into
years. It continued to occasionally make the same ghastly noises that
never should be heard coming from a hard disk but with absolutely no sign
of any errors being logged or damage to data whatsoever. The noises seem
to be associated with seek activity because I have never heard them when
the disk is just spinning but otherwise idle. I eventually retired it
and replaced it with a much larger one, purely because I ran out of
space on it. Any thoughts on what might be happening with it?
Regards,
Peter Coghlan.
18 Feb
18 Feb
4:19 a.m.
On Sat, 16 Feb 2019 at 01:43, Peter Coghlan via cctalk
<cctalk at classiccmp.org> wrote:
Days turned into weeks, weeks into months and months
into
years. It continued to occasionally make the same ghastly noises that
never should be heard coming from a hard disk but with absolutely no sign
of any errors being logged or damage to data whatsoever. The noises seem
to be associated with seek activity because I have never heard them when
the disk is just spinning but otherwise idle. I eventually retired it
and replaced it with a much larger one, purely because I ran out of
space on it. Any thoughts on what might be happening with it?
Ha!
Well that is the thing, of course. I had that with one old IDE disk,
too. It made a terrible ear-piercing high whine that I associate with
a failing disk... but it passed every diagnostic I could throw at it,
so I used it for non-critical stuff and in testbed machines.
For about 4 or 5 *years*. It was one reason to run machines with the
case covers on, to muffle the noise. But it ran faultlessly for years.
I think in the end I sold it on to someone, with a warning of course.
That's how I dispose of all kit -- pass it on to a new owner. I try
never to scrap or recycle anything at all.
That's the problem with rule-of-thumb diagnoses. Sometimes they fail.
But more often, things fail with no warning, so it's still useful.
This is why I disregard everyone's accounts of hard disk brands they
won't touch. I did PC tech support for ~25 years. I've seen every make
of hard drive ever fail randomly, and I've seen every make of hard
drive ever work flawlessly for years even when vilely abused.
My experience is extensive enough that _anyone's_ justifications of
why they won't use Brand X disks get ignored, because if I took them,
I would not use _any_brand of disk. Everyone who's been around a bit
has a horror story and the intersection in the Venn diagram, while
small, excludes all vendors ever.
I've never seen any one make that is significantly worse than any other.
--
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Email: lproven at cix.co.uk - Google Mail/Hangouts/Plus: lproven at gmail.com
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1:16 p.m.
On Mon, 18 Feb 2019, Liam Proven via cctalk wrote:
Well that is the thing, of course. I had that with one
old IDE disk,
too. It made a terrible ear-piercing high whine that I associate with
a failing disk... but it passed every diagnostic I could throw at it,
so I used it for non-critical stuff and in testbed machines.
One of the moxt common causes of a terrible ear-piercing high whine is the
spindle contact. Many old drives had a springy piece that rubbed against
the end of the spindle. Over time, it would wear a divot, polish that,
and start to squeal. A very light pressure on it would test that
hypothesis. Not enough pressure to muffle the sound, and certaianly not
enough pressure to slow the spindle! Or, pulling up on it, away from the
spindle. Some people claimed that you could just rip it off. Don't.
Best is to twist it very slightly sideways, so that it can start wearing a
new divot.
My experience is extensive enough that _anyone's_
justifications of
why they won't use Brand X disks get ignored,
Well, there don't seem to be many 350 RAMAC disks still running.
(I'm trying to decide what to use as a base to make a patio table out of a
[crashed] RAMAC 24" platter)
--
Grumpy Ol' Fred cisin at xenosoft.com
1:38 p.m.
On Feb 18, 2019, at 4:16 PM, Fred Cisin via cctalk
<cctalk at classiccmp.org> wrote:
On Mon, 18 Feb 2019, Liam Proven via cctalk wrote:
Then again, I remember our college RS64 (drive for the RC11) which developed a bad motor
bearing. Since the platter is mounted directly on the motor spindle that was a problem.
And it was not under contract, so replacing the motor would have set back the department a
substantial sum. So the DEC FS engineer removed the motor and carried it to Appleton
Electric Motor Co., which pulled the old bearing, pressed on a replacement, and handed it
back. Jim reinstalled the motor, all was well. Didn't even lose any data bits.
paul
Well that is the thing, of course. I had that
with one old IDE disk,
too. It made a terrible ear-piercing high whine that I associate with
a failing disk... but it passed every diagnostic I could throw at it,
so I used it for non-critical stuff and in testbed machines.
One of the moxt common causes of a terrible ear-piercing high whine is the spindle
contact. Many old drives had a springy piece that rubbed against the end of the spindle.
1:47 p.m.
On 2/18/2019 3:38 PM, Paul Koning via cctalk wrote:
Nice of the FE to do that.
The Univ. of Wisconsin CS Department had one of those, but the platter
went bad. They just flipped the platter upside down and got more use
out of it.
The Univ. of Wisconsin ECE Department also had one - the two machines
were nearly twins. I *have* *that* one - and it still ran when I tried
it a year or so ago.
On Feb 18, 2019, at 4:16 PM, Fred Cisin via
cctalk <cctalk at classiccmp.org> wrote:
On Mon, 18 Feb 2019, Liam Proven via cctalk wrote:
Then again, I remember our college RS64 (drive for the RC11) which developed a bad motor
bearing. Since the platter is mounted directly on the motor spindle that was a problem.
And it was not under contract, so replacing the motor would have set back the department a
substantial sum. So the DEC FS engineer removed the motor and carried it to Appleton
Electric Motor Co., which pulled the old bearing, pressed on a replacement, and handed it
back. Jim reinstalled the motor, all was well. Didn't even lose any data bits.
paul
Well that is the thing, of course. I had that
with one old IDE disk,
too. It made a terrible ear-piercing high whine that I associate with
a failing disk... but it passed every diagnostic I could throw at it,
so I used it for non-critical stuff and in testbed machines.
One of the moxt common causes of a terrible ear-piercing high whine is the spindle
contact. Many old drives had a springy piece that rubbed against the end of the spindle.
1:59 p.m.
On Feb 18, 2019, at 4:47 PM, Jay Jaeger via cctalk
<cctalk at classiccmp.org> wrote:
On 2/18/2019 3:38 PM, Paul Koning via cctalk wrote:
Yes, that was a feature. You had to reformat it, which required getting the timing track
writer box from Maynard. I have seen that done on an RS11 (RF11) drive on our RSTS
system; it crashed some heads and was rebuilt completely (new heads, new platter, new
motor).
...
Then again, I remember our college RS64 (drive for the RC11) which developed a bad motor
bearing. ...
Nice of the FE to do that.
The Univ. of Wisconsin CS Department had one of those, but the platter
went bad. They just flipped the platter upside down and got more use
out of it. The Univ. of Wisconsin ECE Department also had one -
the two machines
were nearly twins. I *have* *that* one - and it still ran when I tried
it a year or so ago.
Neat. You can run RT11 on it if you add the boot loader and driver, at least old
versions. DOS V4 also supports it. And older versions of RSTS can use it as a swap
disk.
paul
19 Feb
19 Feb
3:10 a.m.
On Mon, 18 Feb 2019 at 22:16, Fred Cisin via cctalk
<cctalk at classiccmp.org> wrote:
One of the moxt common causes of a terrible ear-piercing high whine is the
spindle contact. Many old drives had a springy piece that rubbed against
the end of the spindle. Over time, it would wear a divot, polish that,
and start to squeal. A very light pressure on it would test that
hypothesis. Not enough pressure to muffle the sound, and certaianly not
enough pressure to slow the spindle! Or, pulling up on it, away from the
spindle. Some people claimed that you could just rip it off. Don't.
Best is to twist it very slightly sideways, so that it can start wearing a
new divot.
It was a 3?" EIDE drive. 8GB one, I think, but might have been
smaller. I didn't want to open it to do that, although there was a
time when custom PC builders "de-lidded" hard disks and fitted them
with little acrylic windows so you could see the head move. Not sure
I'd want to trust my data to that...
Well, there don't seem to be many 350 RAMAC disks
still running.
(I'm trying to decide what to use as a base to make a patio table out of a
[crashed] RAMAC 24" platter)
Conceded.
And thank you for the reminder that I'm not old yet.
My first machine with a hard disk was my work PC in my first job: an
IBM PC-AT, with a 20 MB FS/FH 5?" ST-506 drive, probably a Seagate
ST-4026. I added a second drive to the machine, a 15 MB one, and put
Xenix/286 on it.
A few years ago I bought a surplus 2?" 1 TB drive from a chap who'd
bought a new notebook and put an SSD in it before use. So, 2nd hand
but unused.
It cost me CzK 1000, about ?30 at the time.
?30 for a terabyte. I was in a state of shock. It was so tiny, too.
I found an online capacity comparator thing.
You'd need a pile of those Seagate drives the size of a _space
shuttle_ to hold a terabyte.
https://liam-on-linux.livejournal.com/53353.html
--
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Email: lproven at cix.co.uk - Google Mail/Hangouts/Plus: lproven at gmail.com
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1 p.m.
New subject: HDDs (Was: PDP-11/45 RSTS/E boot problem
> One of the moxt common causes of a terrible
ear-piercing high whine is the
> spindle contact. Many old drives had a springy piece that rubbed against
> the end of the spindle. Over time, it would wear a divot, polish that,
> and start to squeal. A very light pressure on it would test that
> hypothesis. Not enough pressure to muffle the sound, and certaianly not
> enough pressure to slow the spindle! Or, pulling up on it, away from the
> spindle. Some people claimed that you could just rip it off. Don't.
> Best is to twist it very slightly sideways, so that it can start wearing a
> new divot.
On Tue, 19 Feb 2019, Liam Proven via cctalk wrote:
It was a 3?" EIDE drive. 8GB one, I think, but
might have been
smaller. I didn't want to open it to do that, although there was a
time when custom PC builders "de-lidded" hard disks and fitted them
with little acrylic windows so you could see the head move. Not sure
I'd want to trust my data to that...
Yes.
I was thinking in terms of slightly older drives than that, particularly
5.25"
Getting at the slider on newer drives wouldn't be practical.
Well, there
don't seem to be many 350 RAMAC disks still running.
(I'm trying to decide what to use as a base to make a patio table out of a
[crashed] RAMAC 24" platter)
Conceded.
And thank you for the reminder that I'm not old yet. My first machine with a hard disk was my work PC in my
first job: an
IBM PC-AT, with a 20 MB FS/FH 5?" ST-506 drive, probably a Seagate
ST-4026. I added a second drive to the machine, a 15 MB one, and put
Xenix/286 on it.
You could run Xenix on an XT!
The stock IBM XT HDD controller (Xebec) had physical solder pads for drive
type, and supported 5MB, 10MB, 15MB, and 25MB drives. The 25 was, of
course, best (if you could get one) and would permit a 10MB DOS partition
dual booting with 15MB Xenix. Was that the first "dual boot" in the
PC world? (or was there a CP/M-86 dual boot option once they added HDD
support?)
A few years ago I bought a surplus 2?" 1 TB drive
from a chap who'd
bought a new notebook and put an SSD in it before use. So, 2nd hand
but unused.
It cost me CzK 1000, about ?30 at the time.
?30 for a terabyte. I was in a state of shock. It was so tiny, too.
I found an online capacity comparator thing.
I used a lot of ST4096 drives. Needed a second AT power supply for the
second one.
You'd need a pile of those Seagate drives the size
of a _space
shuttle_ to hold a terabyte.
https://liam-on-linux.livejournal.com/53353.html
I use 2TB 2.5" 7.5mm Seagate/Samsung drives for MP4s of movies in
laptops and with a Seagate GoFlex-TV (media streamer with SATA slot)
But, I finally filled 2TB
Currently, that is the largest 7.5mm 2.5" drive available. But SSDs are
now available in 2TB, so when that price comes down, . . .
Heard about the NSA Utah Data Center?
https://nsa.gov1.info/utah-data-center/
That's a LottaBytes!
--
Grumpy Ol' Fred cisin at xenosoft.com
20 Feb
20 Feb
4:49 a.m.
New subject: HDDs (Was: PDP-11/45 RSTS/E boot problem
On Tue, 19 Feb 2019 at 22:00, Fred Cisin via cctalk
<cctalk at classiccmp.org> wrote:
Yes.
I was thinking in terms of slightly older drives than that, particularly
5.25"
Getting at the slider on newer drives wouldn't be practical.
Probably not. I suspect that ITRO 90+ % of the people I work with have
never seen a 5?" hard disk. CD-R or DVD, yes, but they're possibly
unaware that HDs used to come in that formfactor.
I've had arguments with people over the meaning of "full height" and
"half height" before, because to them, the physically biggest drive
they've ever seen, in ancient kit (to them), is a CD drive. So
logically that _must_ mean "full height" because nothing is bigger,
therefore they redefined all the terms in their heads...
The RAMAC came out in 1956? The platters are 24"
diameter. Each platter
was almost 100K! But, with 50 platters, it maxed out at almost 5MB.
When Nikita Khruschev made a peace mission to USA, they took him on a tour
of the RAMAC facility. But, they wouldn't let him go to DisneyLand! (THAT
had repercussions in the Cuban missile crisis)
11 years before I came out, then.
I've seen and played a bit with some machines with 8" floppies, but I
think that's the biggest. I never saw the VAX 11-780 I learned Fortran
on.
You could run Xenix on an XT!
True, but I think it wasn't a lot of use for commercial multiuser
accounts systems. They were the main market for Xenix for my
employers, early in my career. My 1st job sold Tetra, mainly
TetraPlan.
Checks... huh, later bought by Sage:
https://www.theregister.co.uk/1999/03/08/accounting_for_sages_move/
Later, I worked for places that sold other things, like SystemsUnion.
Happily a market I left long ago and have forgotten about.
The stock IBM XT HDD controller (Xebec) had physical
solder pads for drive
type, and supported 5MB, 10MB, 15MB, and 25MB drives. The 25 was, of
course, best (if you could get one) and would permit a 10MB DOS partition
dual booting with 15MB Xenix. Was that the first "dual boot" in the
PC world? (or was there a CP/M-86 dual boot option once they added HDD
support?)
DOS+ could dual-boot with PC DOS, as I recall. I think CDOS could too.
So, probably.
I'm quite glad the XT was fading away as I got into the PC business.
They were weird and constrained.
Still, not knowing about them means people working on PCs now don't
know where it came from...
I used a lot of ST4096 drives. Needed a second AT
power supply for the
second one.
Ha! Yes, I can believe that. IBM did under-spec the PSUs, though.
I use 2TB 2.5" 7.5mm Seagate/Samsung drives for
MP4s of movies in
laptops and with a Seagate GoFlex-TV (media streamer with SATA slot)
But, I finally filled 2TB
Currently, that is the largest 7.5mm 2.5" drive available. But SSDs are
now available in 2TB, so when that price comes down, . . .
Heard about the NSA Utah Data Center?
https://nsa.gov1.info/utah-data-center/
That's a LottaBytes!
O_o
Reminds me... I should buy a few more tibs, consolidate and rearrange
some stuff.
I wonder why megs and gigs caught on, but there's no common shorthand
for terabytes?
--
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Email: lproven at cix.co.uk - Google Mail/Hangouts/Plus: lproven at gmail.com
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UK: +44 7939-087884 - ?R (+ WhatsApp/Telegram/Signal): +420 702 829 053
15 Feb
15 Feb
3:23 p.m.
Jeffrey S. Worley wrote:
Back in 2000-ish, I was upgrading my DG MV4000/dc to 8mb so as to be
able to run the snazzy AOS/VS II tapes I'd got along with the 9 track
drive I hacked onto the machine...
The install would start and then bomb at a certain point every time. I
decided to work the machine hard and then pull the board and give a
good SNIFF. This is a 15x15 inch board populated with 256kx1 drams.
The time in the machine got the board cooking nicely, and when I
smelled a certain charred smell in the vicinity of a 74ls04, I knew it
was that magic black smoke. I pulled a 74HCT04 from a known-good isa
card, socketed the spot and viola! Working 8mb board. It isn't
ALLWAYS the most expensive chip, thank God, and sometimes even us not-
as-bright guys come off with a win.
About 20 years earlier than that, one of my friends at school asked me to
fix his Jupiter Ace which had stopped working. I told him I didn't hold
out much hope for success because I didn't have the vaguest idea how his
little machine worked at that time but I agreed to wave my multimeter in
the general direction of it's power supply. I opened it up and quickly
found that the voltages seemed very reasonable and I prodded around the
board rather aimlessly looking for some part that looked guilty. I soon
noticed that one of the eight identical chips in a row at the bottom of
the board was getting hot enough to burn my finger while the others
remained cool and calm. I can't remember where I got a replacement 4116
or 4164 or whatever it was - I probably had to get it mail order but once
it was soldered in with fingers crossed that nothing else was wrong, the
machine came right back to life. Sometimes you just get lucky. I wish I
could be that lucky with some of my own stuff now.
Regards,
Peter Coghlan.
1915
days inactive
1920
days old
13 comments
6 participants
participants (6)
-
cctalk＠beyondthepale.ie -
cisin＠xenosoft.com -
cube1＠charter.net -
lproven＠gmail.com -
paulkoning＠comcast.net -
technoid6502＠gmail.com