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Date
Re: Service manual scan post processing

 

On Tue, 18 Feb 2025 at 17:37, Peter Brown via <peter=[email protected]> wrote:
Hi David,
I am wondering if the claimed 600 dpi is actually the result of interpolation / dithering
I will upload a page at 600 DPI in bmp format for completeness in case the no compression .tiff actually has some compression
And then drop the resolution down to 300 DPI and save as bmp and tiff
Thanks for your help with this

If I understand correctly, you are using a digital camera to take a picture, then processing that.

Could you please upload the jpg file produced by the camera, without any other processing.
Re: Service manual scan post processing

 

Hi David,
I am wondering if the claimed 600 dpi is actually the result of interpolation / dithering
I will upload a page at 600 DPI in bmp format for completeness in case the no compression .tiff actually has some compression
And then drop the resolution down to 300 DPI and save as bmp and tiff
Thanks for your help with this?
Peter
Re: Service manual scan post processing

 

On Tue, Feb 18, 2025 at 11:49?AM Tom Gardner via groups.io
<tggzzz@...> wrote:

That is highly beneficial, and is the way the scancvt script I posted earlier reduces pages to ~80kBytes for a page of text.
The scancvt script determines the average colour, then quantises it into two levels.
Thanks, I'll have to try and remember that script in the future.

My current process converts things to PNM, iterates over 0.0 to 0.9
(by 0.1) into pamthreshold, then back to TIFF. I'll look through
all the threshold'ed images, and pick the one that looks best most
times.

My process is clunky, and disk intensive.
Re: Service manual scan post processing

 

Nope, those appear to be dithered too.. (and show indications of JPEG
compression).

I uploaded a high zoom'd screenshot of what I'm seeing..

Sorry...

On Tue, Feb 18, 2025 at 11:51?AM Peter Brown via groups.io
<peter@...> wrote:

Hi David
I have added some of the raw .tiff output from the MS-800 in a tiff subdirectory.
Perhaps these are more suitable for contrast enhance etc?
Peter
Re: VNA Fixtures

 

That may well be necessary if I encounter one of those 'problem child' devices that Ed described!
Re: Service manual scan post processing

 

Hi David
I have added some of the raw .tiff output from the MS-800 in a tiff subdirectory.
Perhaps these are more suitable for contrast enhance etc?
Peter
Re: Service manual scan post processing

 

On Tue, 18 Feb 2025 at 16:03, David Holland via <david.w.holland=[email protected]> wrote:
I think you may be missing a contrast maximization step.? If you zoom
in, the pages appear to be greyscale, dithered down to black and
white.? I don't think you're going to get much better compression than
what you've got.

When I'm scanning I'll scan to individual 8bit greyscale, ( or full
RGB color ) TIFF files, and then push everything through a contrast
enhancement step to blow out the contrast, before conversion to black
and white.? ?eg: Blacks areas are fully black, whites are fully white.

That is highly beneficial, and is the way the scancvt script I posted earlier reduces pages to ~80kBytes for a page of text.
The scancvt script determines the average colour, then quantises it into two levels.
Re: VNA Fixtures

 

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If you have a lot you can carefully disassemble one of each to get further knowledge.?

Peter

On Feb 18, 2025, at 8:34?AM, Jinxie via groups.io <paul666@...> wrote:

?
Ed, many thanks for that comprehensive answer. All bar one of these devices have that capacitor you describe tucked away in the base. Can't be more than a few tens of pF at most I'd have thought. The sole exception is one with 6 pins instead of 5 for some reason. The 5 pin ones have 3 on one side and 2 on the other and I *believe* the 3 side is input and the 2 pin side is output. Normally only two of the three input pins are used. I think there's an extra inductor in there if you want to use it in which case you connect to the two outer pins. Seems there's a bit more to these trannies than first appears!
Re: VNA Fixtures

 

Ed, many thanks for that comprehensive answer. All bar one of these devices have that capacitor you describe tucked away in the base. Can't be more than a few tens of pF at most I'd have thought. The sole exception is one with 6 pins instead of 5 for some reason. The 5 pin ones have 3 on one side and 2 on the other and I *believe* the 3 side is input and the 2 pin side is output. Normally only two of the three input pins are used. I think there's an extra inductor in there if you want to use it in which case you connect to the two outer pins. Seems there's a bit more to these trannies than first appears!
Re: Service manual scan post processing

 

I think you may be missing a contrast maximization step. If you zoom
in, the pages appear to be greyscale, dithered down to black and
white. I don't think you're going to get much better compression than
what you've got.

When I'm scanning I'll scan to individual 8bit greyscale, ( or full
RGB color ) TIFF files, and then push everything through a contrast
enhancement step to blow out the contrast, before conversion to black
and white. eg: Blacks areas are fully black, whites are fully white.
G4 compression works *much* better on areas of absolute color, vs
dithering.

I've got some commands from NetPBM / pamthreshold that'll do it under
Linux, but I don't know of a tool to conveniently do it w/ Windows.

On Tue, Feb 18, 2025 at 9:45?AM Peter Brown via groups.io
<peter@...> wrote:

Hi Michael,

Many thanks for responding. Please do take a look at the files, I have posted some pdfs here
Files - A temporary directory for photographs and help relating to emails and posting - 8430A 08340-90021 Service vol 1 section1
but if it is of use I can add some of the raw .tiff images that the scanner produces

After lurking on auction sites for ages, I also have a Kodak 2400DSV-E which I believe is the same as the Minolta MS-6000 - not sure if this works electrically yet (building up an XP PC to work with it) but mechanically it seems fine.
We have a saying here in the UK - it's like a number 10 bus, you wait around for ages then two come at once.

Let me know how you get on with the pdfs and if you need a few .tiff files to try

Peter
Re: Disassembling HP 64000 code

 

Thank you Don and Steve. The assembly code looks exactly like how FORTH is described. The main code sets up a processing engine which gets fed lists of pointers that reference either real assemble code or more lists of pointers. The dictionary or link list I described gives names of functions and pointers to the code.

I'll read up more on FORTH and see if it gives anymore insight to the codes unknown bits.


On Tue, Feb 18, 2025, 11:33?PM Steve Hendrix via <SteveHx=[email protected]> wrote:
On 2025-02-18 9:13 AM, Don Bitters via wrote:
> You might want to check this site for information about FORTH. I
> believe the HP64000 did support FORTH in some of the early versions.

I was also thinking from your description of the memory contents you
found, that it sounds like a stored FORTH program. I implemented
FORTH-77 on a 6502 back in the early 80's, and I still have some
documentation around here somewhere. Basically a FORTH program consists
of a set of "words" that build upon one another until you get to the
"main" word that does the whole program. Each word is usually stored
with the text as you saw, a link to the machine code that executes that
word's action, and in many cases, a list of pointers to the other words
it calls. Quite an interesting language, very powerful compared to BASIC
(which was all my funds allowed access to in those days), and rightfully
dubbed a "write-only language". However, it made unit testing
straightforward, because every word could be executed directly from the
command line, so it was easy to test as you code. Sort of a hybrid
between a compiler and an interpreter.

Steve Hendrix
Re: Dissassembling HP 65000 code

 

Sven,

Can you reply to the new thread with the Bitsaver and Mame information? Both are valuable to the discussion and I hope to include it in the correct thread.

Thanks

On Tue, Feb 18, 2025, 3:46?PM Sven Schnelle via <svens=[email protected]> wrote:
"Tom Haynes via " <=[email protected]> writes:

> Is anyone here familiar with data structures build by the HP 65000
> system?

Are you sure it's 65000? I only know about the 64000 and 647000 systems.

My firmware has:

00001b60? 42 1e a8 61 f6 1c fa 60? 42 12 5c 10 42 3c 36 38? |B..a...`B.\.B<68|
00001b70? 30 39 20 37 39 2d 53 54? 44 20 46 4f 52 54 48 20? |09 79-STD FORTH |
00001b80? 77 2f 48 50 36 34 30 30? 30 20 73 69 6d 75 6c 61? |w/HP64000 simula|
00001b90? 74 65 64 20 49 2f 4f 20? 20 42 4a 53 20 52 65 76? |ted I/O? BJS Rev|
00001ba0? 2e 20 30 39 2f 30 31 2f? 38 33 22 68 10 42 3c 4d? |. 09/01/83"h.B<M|
00001bb0? 6f 64 69 66 69 65 64 20? 66 6f 72 20 52 4f 4d 20? |odified for ROM |
00001bc0? 62 61 73 65 64 20 6f 70? 65 72 61 74 69 6f 6e 20? |based operation |

> While dissassembling firmware code for the HP 3457A multimeter I found
> a block of code that is inaccessible from the code
> while run in the meter. It appears to be symbol tables and simulator
> code for the 65000 build environment. I was able to
> use it to give names to all of the functions but there are some parts
> of the data structure I can't figure out.
>
> There was also some references to PASCAL but I couldn't find any info
> about PASCAL being a supported language on the
> 65000. Maybe it was just describing the use of Pascal Strings.

Look on , especially the files in


It contains the full source of HP's version of pascal. I only know it
from HP 9000/300 workstations, but i wouldn't be surprised if it was
also used for/in other projects. On the other hand does the comment
above say FORTH, but i have no idea about FORTH, so can't say anything
about that.

BTW, i hacked a pseudo driver for the 3457a years ago in mame to do some
reverse engineering. Not sure if it's of any help, but here's the commit:



It's good enough to display an Error message on the emulated display
because it can't talk to any measurement hardware.
Re: Service manual scan post processing

 

Hi Martin,
?
Thanks for the steer on ImageOptim, I will take a look.?
?
I am in touch with a service engineer who used to run a company that printed microfiche and also supplied the reader / scanners.?
He is recommending something called PaperPort - any members have experience with this package?
?
Peter
Re: Service manual scan post processing

 

Hi Michael,
?
Many thanks for responding.? Please do take a look at the files, I have posted some pdfs here?
Files - A temporary directory for photographs and help relating to emails and posting - 8430A 08340-90021 Service vol 1 section1
but if it is of use I can add some of the raw .tiff images that the scanner produces
?
After lurking on auction sites for ages, I also have a Kodak 2400DSV-E which I believe is the same as the Minolta MS-6000 - not sure if this works electrically yet (building up an XP PC to work with it) but mechanically it seems fine.?
We have a saying here in the UK - it's like a number 10 bus, you wait around for ages then two come at once.
?
Let me know how you get on with the pdfs and if you need a few .tiff files to try?
?
Peter
?
?
Re: HP 8670B amplifier - does it ring a bell with anyone?

 

If System Component serial numbers follow classic Hewlett Packard rules, that 6870B would have been built in 1990.? That said, there seem to be 1991 and 1992 stampings on the rear upper left of the chassis. Given that the serial number tag seems partially covered by the chassis, I am wondering the working gubbins were re-bodied in to a System Component chassis.
?
Why would someone do that, I have no real idea, unless they were testing their Turbo Encabulator.
Re: Disassembling HP 64000 code

 

On 2025-02-18 9:13 AM, Don Bitters via groups.io wrote:
You might want to check this site for information about FORTH. I believe the HP64000 did support FORTH in some of the early versions.
I was also thinking from your description of the memory contents you found, that it sounds like a stored FORTH program. I implemented FORTH-77 on a 6502 back in the early 80's, and I still have some documentation around here somewhere. Basically a FORTH program consists of a set of "words" that build upon one another until you get to the "main" word that does the whole program. Each word is usually stored with the text as you saw, a link to the machine code that executes that word's action, and in many cases, a list of pointers to the other words it calls. Quite an interesting language, very powerful compared to BASIC (which was all my funds allowed access to in those days), and rightfully dubbed a "write-only language". However, it made unit testing straightforward, because every word could be executed directly from the command line, so it was easy to test as you code. Sort of a hybrid between a compiler and an interpreter.

Steve Hendrix
Re: HP8673C Restoration project

 

Allan thats a nice generator. I did?troubleshoot one for a friend 5 years ago. It turned out to be the yig coil and no parts were available. He did sell the generator as is and did fine. But that was my experience?as little help to you as that is. I seem to recall the coil R was high but not open.
Paul
WB8TSL
Re: Disassembling HP 64000 code

 

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You might want to check this site for information about FORTH. I believe the HP64000 did support FORTH in some of the early versions.


Don Bitters

Re: HP 8670B amplifier - does it ring a bell with anyone?

 

There is also an 8760B K73 which is a 24 input 2 output switch matrix.
The unit is 19" 4U in size.

I am not sure for what systems were these used.

On 18/02/2025 14:33, David Feldman via groups.io wrote:
Some additional information -

1. The amplifier's full part number is HP 8760B K29 --- the K29 is important, as it appears to be a component in a system, rather than intended as a stand-alone product.

2. Three photographs are attached. The box is mostly power supply inside; the amplifier itself (in a sub-enclosure) is at the rear of the enclosure, exposing two SMA-F connectors on the back panel.

3. A spreadsheet (URL follows) was found online that includes reference to HP 8760B K29 (along with several dozen other "K" numbers. From this it appears the date of manufacture might have been around 1992.



4. Based solely on the relative size of the RF assembly, I'd suspect the amplifier is in the milliwatt range, possibly intended as a gain block for a measurement system.

Re: HP 8670B amplifier - does it ring a bell with anyone?

 

Some additional information -

1. The amplifier's full part number is HP 8760B K29 --- the K29 is important, as it appears to be a component in a system, rather than intended as a stand-alone product.

2. Three photographs are attached. The box is mostly power supply inside; the amplifier itself (in a sub-enclosure) is at the rear of the enclosure, exposing two SMA-F connectors on the back panel.

3. A spreadsheet (URL follows) was found online that includes reference to HP 8760B K29 (along with several dozen other "K" numbers. From this it appears the date of manufacture might have been around 1992.



4. Based solely on the relative size of the RF assembly, I'd suspect the amplifier is in the milliwatt range, possibly intended as a gain block for a measurement system.

hp-8760b-k29-photo-1.jpg
hp-8760b-k29-photo-2.jpg
hp-8760b-k29-photo-3.jpg

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