Mike wrote: I just finished reviewing a few cases sent out for servicing.
One laptop was reported as not booting, - the tech toggled the display -it
had been set to use external monitor.
Another laptop was frozen, it did not respond to crtl-alt-del - the tech
held
in the power button, it was hibernating.
-----------------------------------
Billy:
I've been buying broken iPods minis on eBay for work. One I got was
described as unable to load songs or use the menu. Cost a whole twenty
dollars. I found the Hold switch in lockout. Only visible switch and
dispalys red when on. Toggled the switch and had an iPod in perfect working
condition with a good battery. More than made up for some of the junkers I
get and have to fix.
Billy
Yesterday I was given a fairly hefty documentation set:
Installation and Operation Model 1016
Drum Memory with Digital Interface
Vermont Reserch Corporation
North Springfield, Vermont
Most of the documents are dated 1969.
It contains a lot of technical information, theory of
operation all all the boards, full schematics, copies
of the original blueprint drawings etc.
Anyone need/looking-for this?
Regards,
Dave
PS: Anyone know what type of system this was used
with?
--
dave06a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Collector of vintage computing equipment:
http://www.classiccmp.org/dunfield/index.html
Teo Zenios wrote:
Any how many hard drive companies are actually making a profit moving those
376 Million units?
I don't expect blueprints and electrical schematics with the electronics I
buy. But I do expect some way of finding out if the hardware is actually
broken or something else (software, bad inputs etc) is causing things to not
work. What percentage of returned electronics are sent back 100% working
because people didn't have a good way to troubleshoot what the real problem
was in the system?
TZ
------------------------------------------------------------------
Billy:
I believe that there are six major companies still doing disk drives:
Seagate, Hitachi, Toshiba, Fujitsu, WD and Samsung. Seagate is doing great,
WD about half of Seagate's profit. Samsung, and Fujitsu are profitable.
Toshiba, probably not and Hitachi definitely not.
If you are looking into testing units, look for the SMART attributes. Most
modern drives do elaborate error monitoring and logging. These values are
available to the user by reading out the SMART logs. Some OS's do this as a
matter of course and even present error messages when a drive is starting to
fail.
Finally, recent drives usually have Drive Self Test capability if you want
to invoke diagnostics. The ARM cores used have tremendous potential and
power. An ARM- 9 processor at 400 MHz is far more powerful than any of the
supercomputers I worked on. And they reserve10-20GBs for maintenance use -
many times more drive capacity than any of the supercomputers I used to
maintain.
No Fault Found on returns can vary from 20 to 50%. That is the same ratio
it was 30 years ago. And not surprisingly, it is the same ratio for Optical
drives, game machines, printers, etc. It is not so much not able to
troubleshoot as the fact that when a system goes in for repair, they usually
swap out a hard drive. When that doesn't fix the issue, the techs don't
put the original drive back. On all electronics, there are many user
influenced errors that can never be reproduced. Static is one; power
failures, partially plugged in sockets, shock, vibration from the
environment, noisy AC power, and on and on. There are a large number of
external conditions that can cause equipment failure. If you are not there,
you don't know what the conditions are.
Of course there is the other extreme. I worked on a computer once that the
building contractor had tied the lightning rod to the grounding plane of the
computer room. Every single PCB in the system was fried. I saw an IPod
recently that had been run over by a bull dozer. We often get calls about
recovering data from laptops dropped into a lake or the ocean. I have the
case of an XBox that had been hit with a sledge hammer by a frustrated wife.
Optical is usually sent in for foreign material in the disk tray. On the
game machines that I gathered stats on, the number one failure was 2 or more
CDs. The users thought they could stack up games like a phonograph. And I
thought finding pizza in a DVD was bizarre until I checked the logs and
found we averaged one of two a week. I guess a game system is warm and
lends itself to being an oven.
Billy
Tony Duell wrote:
Well, if I've got a few hundred megs of data on a hard drive, I'd rather
repair a simple electronic fault than have to restore it all from
backups. And it would take me lest time to repair such a fault than it
would take to ship the replacement drive.
-Tony
------------------------------------
Billy -
I'll try one last time and then give up. Tony, hard drives rarely rarely
have a simple electronic fault. The ratio of mechanical to electrical
faults is around 98 to 1. They are so rare that most companies don't repair
PCBs.
You cannot repair mechanical failures in drives made in the last 25 years
without highly specialized equipment. Drives made in the last ten years
require Class 10 clean rooms, thanks to flying heights less than the
wavelength of visible light.
Yes I know you have a few early primitive drives that you fixed in the past.
But technology has moved a long long ways from those Paleolithic days. We
still repair drives, we still use technicians, but they sure as hell don't
use soldering irons, oscilloscopes and schematics.
And no, we didn't lose any customers because we stopped providing
maintenance manuals. The demand for disk drives soared last year to 376
million units, a 23% jump over the previous year. I know you didn't buy
any, and we'll have deal with that loss. But out of the tens of millions we
sell every quarter, not a single paying customer asks for documentation
other than spec sheets and the fluff manual that is standard today.
And none of those customers have the slightest interest in any kind of
repair.
So tell me - why in the hell should we do something as pointless as provide
documentation that will go unused? If you want to influence that SOP, buy
some new product and demonstrate the need. Exercise your power by purchase.
Otherwise, accept that the rest of the world doesn't like nor want equipment
that requires repair.
And please stop complaining about the lack of manuals. They ain't gonna
happen. The products you like to work on were obsolete before most of our
engineers were born. The world isn't going to back up to meet your needs.
So why don't you develop new skills and learn how to repair this new
equipment? Expand and learn - a lot of us here are older than you and had
no trouble adapting to technological change.
If you insist on only using trivial Stone Age technology, it's your choice.
But you're missing out on equipment many times more exciting and fun to use.
There's a place for you at the cutting edge. And you can still have your
toys; have your cake and eat it too. And if not, well we'll miss you.
Billy
"Jay West" <jwest at classiccmp.org> wrote:
> If you've got one in front of you, why do you need pictures of the inside?
to answer questions like: does this bracket do this way or that way?
also was that placed like that on purpose?
Some machines (esp old ones) have been modified and you may want to
bring it back to its nominal state (esp if you are investigating
some strange behaviour).
Another example is the 9825A where a flat cable does not follow
the convention that the red stripe should be near side of the
connector with the little triangle. On a machine with voltages
ranging from -20 to +20 you'd better plug in stuff the right way.
Having said that, I usually take pictures of the machine as I take
it apart to make sure I can go back and check things. In the case
of the 9825A I assumed that having the service manual (original with
readable photos) would be sufficient. False! I had to check the location
of the ground connections to be sure that the connector was going in
the "wrong" way (red stripe away from the triangle).
In fact the same flat cable plugs in the other way round (red stripe
near the triangle) to the I/O connector, which leads me to believe that
HP people at the time either ignored or were unaware of this convention.
**vp
If the OP is looking for a new scope that's cheap, here at McGill,
we've been using the PicoScope USB scopes in the EE labs (DSP
Hardware). We trust undergrads with them, and they're a heck of a lot
easier to store (if you have 10 of them in a lab). No knobs or
buttons, just 2 BNC and a USB-B on a white box the size of a hardback
book.
Unfortuantely they are Windows-only, so no use for someone like me
who's only got Mac and NetBSD at home.
And it's quite possible to find a good used analog scope for less, I
think, but a digital storage scope has some advantages...
Joe.
Tony Duell wrote:
> single board drives, we didn't want them to repair the units. The =
No, you'd rather sell them a replacement drive than have them replace some
$1 component (I've seen a Wren, there's a lot that can be field-repaired on
one, expecially given a schematic).
----------------------------------------------------------------------------
----
Billy:
Once again you missed the point. Sure there's a few items on Wren that
could be repaired. Though in all the hundreds of thousands built, I never
saw a single PCB failure. And I wish you would consider your time as
valuable. Repair, as you said earlier, is not about the 10P resistor but
about the knowledge and experience of the technician. It is not free.
Maybe everybody, could fix it without damaging it. But if they didn't, then
the manufacturer is liable for the botched repair. And don't say this
didn't happen. For almost 10 years, those of us in Field Service had to go
out and clean up the messes that so called trained engineers created. I
have enough stories about the idiocy prevalent in the computer repair field,
that I've started writing a book about some of them. We did not want to
cater to this tiny miserable bunch that caused so much grief and expense, so
we forced a change. And it became a standard for peripheral companies.
Eliminating maintenance and repair on hard drives saved tens of millions of
dollars and raised our customer satisfaction enormously.
The main point is: to accommodate the whimsy of one hobbyist, we would have
had to invest 100's of thousands of dollars in technical manuals, keep them
up to date, make them available. The Wren had more than 50 variations - I
know because I had to track them. It would have required a staff of 20 to
keep the manuals accurate. Making a maintenance manual available would have
been a disastrous financial mistake.
And for what purpose? Only one person in the world would use this
documentation. Everyone else would prefer to spend the $50 on a new drive
than risk reusing a repaired one
Billy.
Chuck Guzis wrote: On 6/8/2006 at 7:59 PM Billy Pettit wrote:
>Billy:
>There were several reasons, but the biggest one was: they could do
parallel
>read and writes. You could stripe them for 16 bit wide data paths that
>became incredibly fast. And with virtually no bit skew. Plus access time
>was never more than one revolution.
Yeah, but in a Star-100 SBU, there was enough memory in the thing that the
drum hardly got used past booting the thing up. There was just no point to
the speed. The Star paged to disk; there were some plans initially for a
huge drum, running something like 512 bits parallel, but I don't know if
the concept ever made it off paper.
The funny thing was that there were the same SBUs on the two Star-1B's in
Sunnyvale--the SBU's were qutie a bit faster than the 1Bs themselves.
(Those two systems eventually went into the dumpster per company policy).
During the 60's, drums gave disks a run for their money. I remember a
Univac 1108 with the very large FASTRAND-II moving-head drum on it.
There were a number of late 50's-early-60's machine with drum as the main
memory, such as the IBM 650 and the LGP-30. "one plus one" addressing.
Cheers,
Chuck
----------------------------------------------------------
Billy:
What a meaty message! All sorts of hooks. I'll try to stay in order.
1. The Star-100 was massive. And memory technology was in a transition, so
a lot of the plans changed mid-stream. That was part of what killed it. By
time it was working, it was obsolete. The storage concept came from 7600
ideas. You are dead on with the word staging. What software wanted was to
stage ALL data transfers. The program would be loaded (including all
required data tapes) from a tape station. In turn, the tape station would
send the package to the storage station via memory to memory transfer. Then
the storage station would transfer to the main memory also via memory to
memory. Except that this transfer was supposed to be via 512 bit
SWords(SuperWords). It was sort of the ultimate of Seymour's philosophy of
using the CPU for calculating and every thing else was done off line.
2. The drum was an interim device. There was a point to it - the speed was
needed to debug the channels and the streaming busses. This program
required a lot of band aids while waiting for the new technology to come
along. It made a lot of risky bets on new peripherals to keep up with the
speed. The 512 bit wide drum did get to the prototype stage. But it was
incredibly costly. To get the bit density and performance needed, the
entire drum was filled with Helium under pressure. But it was fast. If I
remember the analysis correctly, the big drum would have cost more than the
main frame.
3. The disks were never close to what was needed. Cray was using Ibis and
Fujitsu disk with parallel heads (4 bits at a time). The Star team funded a
parallel head disk from Normandale, but I don't it ever got of the ground
either. They also had a multiple actuator drive in the lab that had the
same problems that caused all other attempts of this idea to fail.
4. The most exotic peripheral I saw was an 18" wide tape unit that used a
helical scan head bar. It was being developed by the Government Systems
Division. It made so much noise that you had to be in another room when it
was running.
5. So there were all sorts of experiments running side by side to find some
way to support the huge data rate required. The drums were more a proof of
concept. They allowed the channels to run at full speed even if they
couldn't supply much data.
6. The Star-1Bs were never intended to be products or peripheral stations.
They were a totally microcoded pseudo-processor. Again, they were proof of
concept, to have something for the programmers to run on. Working Star
hardware was years away when they started the program. The OS needed
development. And the designers needed machines to debug the commands on.
The instruction set was pure IPL. Some of the instructions were very
complex. The Star-1B was frequently recoded as the instruction set was
refined. It wasn't pretty and it wasn't fast. But it was very easy to
reconfigure, the critical parameter at that time.
7. I was assigned to the Star-65 program being developed in Mississauga.
It had to run at least half the Star-100 speed using the same technology
where possible. We had a couple of 1-Bs for the software folks. Used the
same memories and Star Stations. But the processor was a different concept:
the Star-100 was a massive brute force parallel machine. the Star-65 was a
hybrid using some of the streaming units, but with a microcoded main
processor
Damn, those were exciting times! So many new ideas and concepts being
tried. Today, 30 years later, I see an occasional reminder of those Halcyon
machines. For example, the streaming function in ATA-7. Or pipelines in
communication processors.
8. FASTRAND II and III lived on for decodes in the Sabre airline scheduling
systems from Univac. I know some were still in operation until the
mid-1990s. Somebody on the list probably worked on the 490 Series. Anyone?
9. All of the early computers I worked on were drum memory based. In the
Army, it was the Pershing Fire Control Computer. And the Redstone jukebox,
a fixed head sealed disk, actually. But CDC trained me on the Bendix G-15,
LGP-30 and RPC-4000. I can't say I have fond memories of all of them. But
I did prefer drums over disks until the first Winchesters became reliable.
Billy
