On 10/12/20 11:12 PM, Bostonman wrote:

I apologize ahead of time, but I lack experience with Linux, so these commands are confusing me.
The file was downloaded as a .zip, but it contains a file with the extension of .dd. Any 'dd' commands I find seem geared towards using a .iso file to make a bootable drive.
Currently I'm using a Raspberry Pi with a SSD drive connected through a USB adapter.
I looked at the link above, but it doesn't make sense to me. One article stated I need to set the block size, and others have extensively long command lines.
So? I remain baffled at how to handle this.

First, it's important not to overcomplicate things. From your statements I assume you're coming from the Windows world. In the Windows world, it's common to have one or more programs designed to accomplish a specific task and those programs store data in closed, proprietary formats, creating files that will only work with that specific program. If you've got a dozen programs that all accomplish the same task, they'll each use their own format.

The UNIX world is much, much simpler than that. Sure, locked-in file formats do exist, but they are not the norm with common UNIX utilities.

The "dd" program does not have a file format. It copies bytes from one place to another. If you tell it to move bytes from a hard disk drive (not a FILE on a hard disk drive, but from the drive itself), and put them into a file on another hard disk drive, the resultant file will contain a byte-for-byte copy of whatever was on the source hard disk. This is commonly referred to as a "disk image".

The .ISO file format is poorly-named and largely misunderstood. There is no such thing as "an ISO file". ISO refers to the ISO-9660 file format, which is an on-disk filesystem layout intended for use with optical media. There are many such filesystems, but ISO-9660 is very common on optical media. When you make a disk image file (see paragraph above) of a CD-ROM drive, that would be considered to "be an ISO"...whether that CD-ROM originally contained an ISO-9660 filesystem or not. This is typical American terminological laziness at work, and it leads to confusion.

Next, file naming...Another important thing to understand about the UNIX world is that file extensions have no meaning to the system, only to humans. Windows makes a lot of assumptions about the contents of a file based on its extension, but in a UNIX-based OS, there's nothing special about the "." character, and there's nothing special about what may or may not come after it in a filename. Someone having called your file "<filename>.dd" means nothing to the system, and is not used by the system in any way, but it gives me (and soon, you) a clue as to how the file was created if the guy you got it from didn't tell you.

It would be useful for you to learn what the "dd" program does and what it's all about. If you understood it, you would see the "instructions" you found online and immediately see how they would apply to your situation, although they were (poorly) written to focus on "ISOs" of CD-ROM disks. The "dd" program copies bytes between sources and destinations. Sources and destinations can be hard disk drives, CD-ROM drives, floppies, USB thumb drives, files on a disk...anything.

The "dd" program has a lot of options to manipulate data in different ways. Sometimes the block size is important, but a lot of the time it isn't. Most of the time (but not all) it just tells dd to "read or write the data in chunks this big". For some types of devices it's important, for most it isn't, and for files on a drive it means nothing at all...EXCEPT things generally go a whole lot slower if you use a block size of 1 byte, which is the default unless you tell dd otherwise.

I realize learning this is actual work, but this is a give a man a fish/teach a man to fish situation. If you do any amount of "real" computing, you will use this information over and over again. The whole world works this way. The important thing to keep in mind is that UNIX is nothing at all like Windows...do not make any assumptions based on your Windows experience.

-Dave

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Dave McGuire, AK4HZ
New Kensington, PA

Hi,
I have just bought HP 1660A Logic Analyser.
I know I can enter text on the front panel but I would like the keyboard and mouse.
I was buying other gear when I was offered the analyser for a very good price - and no shipping!? I scanned over the keyboard port very quickly when I was checking the machine.? Only when I got home did I realize the HIL part.
I have found a couple of keyboards on ebay for very hopeful prices plus huge shipping to Australia.? There seems to be little consistency in shipping charges, I imported a rack mount receiver last month for less than what these sellers will ship a keyboard.? An untested keyboard.
If anyone has a keyboard and/or mouse available in Australia please contact? me.
Or a suggest a source.

Cheers

Mark

I apologize ahead of time, but I lack experience with Linux, so these commands are confusing me.

The file was downloaded as a .zip, but it contains a file with the extension of .dd. Any 'dd' commands I find seem geared towards using a .iso file to make a bootable drive.

Currently I'm using a Raspberry Pi with a SSD drive connected through a USB adapter.

I looked at the link above, but it doesn't make sense to me. One article stated I need to set the block size, and others have extensively long command lines.

So? I remain baffled at how to handle this.

On 10/12/20 9:19 PM, David B via groups.io wrote:

I have a boat load of stuff to clear out and thought I would see if anyone wants it before going to the local technology re-purposer.
Sony RGB Trinitron monitors used widely on HP series 200/300 computers.
HP Laserjet II and III printers
Sony umatic professional cassette VCR's with tapes.
A couple HP UNIX workstation computers.
A full size wheeled rack cabinet with custom HP 200 series computer, drawers and disc drive.
Big Bertha plotter? 7580B and lots of old still sealed pens
Bunches of smaller stuff, series 200/330 boxes and cards plus instruments, but most motivated to clear out the big stuff first.
Let me know if interested before it's gone.
Located in Oregon, Not really interested in shipping any big stuff unless you want it so bad you are willing to pay my time and cost to prepare and ship it.

Also, I should've mentioned this earlier...please give the folks on the VintHPcom mailing list (also on groups.io). There are a great many people there who will be interested in that hardware and will want to save it from an untimely demise. Please don't recycle this stuff unless you have absolutely no other choice; these systems don't grow on trees and many people strongly want them for either personal or business reasons.

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA

On 10/12/20 9:19 PM, David B via groups.io wrote:

I have a boat load of stuff to clear out and thought I would see if anyone wants it before going to the local technology re-purposer.
Sony RGB Trinitron monitors used widely on HP series 200/300 computers.
HP Laserjet II and III printers
Sony umatic professional cassette VCR's with tapes.
A couple HP UNIX workstation computers.
A full size wheeled rack cabinet with custom HP 200 series computer, drawers and disc drive.
Big Bertha plotter? 7580B and lots of old still sealed pens
Bunches of smaller stuff, series 200/330 boxes and cards plus instruments, but most motivated to clear out the big stuff first.
Let me know if interested before it's gone.
Located in Oregon, Not really interested in shipping any big stuff unless you want it so bad you are willing to pay my time and cost to prepare and ship it.

Unfortunately you're too far away for me to be able to get much of it, but do you have any SRM Coax interfaces (50962A, etc) for 200/300 series systems?

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA

I have a boat load of stuff to clear out and thought I would see if anyone wants it before going to the local technology re-purposer.

Sony RGB Trinitron monitors used widely on HP series 200/300 computers.
HP Laserjet II and III printers
Sony umatic professional cassette VCR's with tapes.
A couple HP UNIX workstation computers.
A full size wheeled rack cabinet with custom HP 200 series computer, drawers and disc drive.
Big Bertha plotter? 7580B and lots of old still sealed pens

Bunches of smaller stuff, series 200/330 boxes and cards plus instruments, but most motivated to clear out the big stuff first.

Let me know if interested before it's gone.

Located in Oregon, Not really interested in shipping any big stuff unless you want it so bad you are willing to pay my time and cost to prepare and ship it.

Regards,
David B

On 10/12/20 7:19 PM, Bostonman wrote:

I'll have to post some pictures again. I don't remember what I posted before, what you read, and what I've already explained.
Basically this scope doesn't have any power cables. It has a CD-ROM, a 3.5" drive, and a 44-pin hard drive. The only power cables are two separate tiny connectors with 5V and ground.
Some good news, I managed to get in touch with the person who owned this before me (I had to dig through old Craig's List emails and try to locate his number). He posted a copy of the original hard drive contents (he no longer has the hard drive), but all I have is a .zip file he created in Linux; and it contains a .dd file.
I'm uncertain how to handle this. I have a laptop with Ubuntu and a Raspberry Pi, but believe I need to take a blank drive and make it a boot drive (I have a Windows program that will do that), but I'm uncertain how to handle the .dd file.
My guess: I create a bootable drive, unzip the .dd. file, and copy/paste all the directories/files onto the bootable drive under the main directory.

No.

The file extension of .dd suggests that he created the file using the program "dd". Though some people do this, there is no standard file naming convention for files manipulated with the "dd" program, which simply moves data around between devices and files. It doesn't know about filesystems or data formats or anything else, just raw data to/from devices.

You will need to use dd on your Linux (or other UNIX) system to write that data back to a drive. One potential issue here is that things may go awry if the destination drive is larger than the original drive was; depending on how Windows handles devices and filesystems. It may deal with it, and it may not. (I'm not a Windows guy)

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA

I'll have to post some pictures again. I don't remember what I posted before, what you read, and what I've already explained.

Basically this scope doesn't have any power cables. It has a CD-ROM, a 3.5" drive, and a 44-pin hard drive. The only power cables are two separate tiny connectors with 5V and ground.

Some good news, I managed to get in touch with the person who owned this before me (I had to dig through old Craig's List emails and try to locate his number). He posted a copy of the original hard drive contents (he no longer has the hard drive), but all I have is a .zip file he created in Linux; and it contains a .dd file.

I'm uncertain how to handle this. I have a laptop with Ubuntu and a Raspberry Pi, but believe I need to take a blank drive and make it a boot drive (I have a Windows program that will do that), but I'm uncertain how to handle the .dd file.

My guess: I create a bootable drive, unzip the .dd. file, and copy/paste all the directories/files onto the bootable drive under the main directory.

Many fans can be given extra life by adding a few drops of light oil on the bearing. ?

Unless the fan winding is burnt out, this method of restoration works well. ?Just carefully peel off the round plastic on top of the fan, add 2 or 3 drops of oil to the bearing ?and reseal. ?I use Nano-oil as I also repair clocks. ?Nano-oil last a long time because of the nano diamond ball bearings are in the oil carrier.
--
Regards, Bernie Murphy

Resistors utilized in metering or other circuits that require good precision is why manufacturers either select their components or rely upon custom made products to their specifications instead of normally available off-the-shelf components.? Custom made parts are why we see such odd values in equipment.? If you are lucky you will find resistors that actually fit normal industry resistance values but are not simply bought in bulk assuming that they will work.? Either that or final test of the product may require change-out of the offending part to obtain the specified operational tolerance of the item.

?

Greg

开云体育

On Mon, Oct 12, 2020 at 01:15 PM, Orin Eman wrote:

'parkertest'

What is (where is) a "parkertest?"
Is there a link to the actual page where (parkertest + Parker Test + Bruce Parker + Parker Test Equipment) quotes < 500 USD, to repair an H.P. power sensor?
It's been mentioned more than once, that people are repairing power sensors... and I'd like to find out what they are doing.

When measuring high value resistors like these you need to be aware of the accuracy limitations of the 3456A on the higher resistance ranges. If you are trying to verify that your resistors are within 1% then it is really beyond the 3456A's resistance measurement capability.

The manual states the accuracy on the 100Mohm range as 1.8% + 1 count, which is close to the error that you are seeing. The accuracy on the 1Gohm range degrades rapidly to 16% + 1 count. Both these figures are the 90-day accuracy so you could expect worse performance if your 3456A hasn't been calibrated in a while.

I suggest you try a different approach by using the resistor under test as the upper leg of a resistive divider with a precision resistor of say 100Kohm in the lower leg. Apply a stable voltage say across the top of the divider and measure the output/input voltage ratio using the ratio measurement function of the 3456A. From the measured ratio a few simple calculations should allow you to derive the unknown resistor value.?

I'm pretty sure I'm going to go with what I have and see whether the meter will calibrate. We'll see.

Thanks,
Barry - N4BUQ

Hello all,
I've just ordered the brass gears from the eBay fellow in India.? Many thanks to all who presented the gear information.
While waiting, I need to replace my noisy fan in my 8640B.?
From the red & black leads going to a nearby board, it appears it is a 5V fan.? My fan has a black colored motor.
Any ideas on the CFM?? Or a fan source?

Thanks