I would like to learn graphics on the RaspberryPi but?I cannot find the right area. It seems to be all games written in Python. It has always seemed?Mickey Mouse to me.

Everyone has free software but the free MS Visual C++ turned out to be $50/month. I wasted 2 weeks on?that when I got?a?message saying my trial period was over.
I don't remember anything that?said?trial when I downloaded?it. I thought it?was a stripped?down version.
I don't mind a few hundred $ like CCS C that?I use often for programming PICs.

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Replies interleaved

Thanks Harvey; I am not ruling anything out. I would like the skills that NewScopes has.

High speed board design, FPGA programming, possibly some microprocessor programming in C or C++.

I will take a look at those displays you mentioned. I can do graphics on a 128x64 LCD using a Digole adapter driven?by a PIC. That is easy.

The F469I-Disco board is an ST micro "discovery" board.? Processor, SDRAM, FLASH RAM, SDcard interface, I2C, USB, built in programmer, SPI, 800 x480 DSI MIPI (an interface) LCD display.

I would like a "C" compiler for my PC. with a useful Graphics library. I just?installed one and wrote a program. Next I will try drawing a box.

I would like to learn graphics on the RaspberryPi but?I cannot find the right area. It seems to be all games written in Python. It has always seemed?Mickey Mouse to me.

The hardware isn't, some of the users might be.? Python is nice, but I don't use it.? I do use C and C++, and have used Pascal.

I also need to learn to use the VESA library and find out what software can use it. Is it free? I'm using Prologix and EZGPIB now. It works.

You may just use the graphics additions to your compiler.

Everyone has free software but the free MS Visual C++ turned out to be $50/month. I wasted 2 weeks on?that when I got?a?message saying my trial period was over.?

Community version....

I don't remember anything that?said?trial when I downloaded?it. I thought it?was a stripped?down version.

I don't mind a few hundred $ like CCS C that?I use often for programming PICs.

I am reluctant to learn Python (or Pascal for EZGPIB, or R to?plot, or all the other suggestions that I am told are so easy).

Well, let's see.

STMicro has a free C/C++ compiler based on eclipse which has a chip configuration tool built in for their ARM processor.? If the display on the board you get has a graphics display, you can use it.? Chip setup and low level drivers are provided (drivers in 2 flavors HAL (higher level) and LL (lower level).? Their demo packages use BSP drivers which are a bit more of a complete package and combine some of the chip inits directly.

I've been doing microprocessor graphics for a bit, and am sitting next to a Disco board running an LCARS display with buttons, screen selection, Icons and an RTC.? There are easier ways to do some of that, though.

I'd go for free to start with, and see what you can do.?

You may want to try the ProgramIO platform (IIRC), it also does C, and may do it for the PC.? I think that there's a solution out there that may do graphics in C++, though.? I just don't really program on the PC in C++ for the PC.

You can likely (if you want) use either a Disco board, or maybe a Nucleo 64 board and use an arduino compatible LCD display, which takes care of the graphics angle, although it may only be 320 x 240.

ST also has FreeRTOS as an add-on and it is integrated into their development system.

If you decide to do C++, (which you can) you need to know the limitations of C++ in their system, do contact me off list.

Harvey

Peter

On Sat, Nov 6, 2021 at 9:04 PM Harvey White <madyn@...> wrote:

You don't need to read the entire 1700 page book.? It's useful for finding out exactly what a section does, or if you wish to program in assembly (depending on which 1700 pages).? More important would be the board manual.

Once you start messing with graphics, things can be complicated, but that very much depends on how you do it.? There are drivers available that work on the board, though.?

The one F469I-disco board needs only scaled inputs.? An arduino style breadboard plugged in can likely give you that and you can access the 4 ADC converter inputs and protect the chip with op amp buffers.? The display is 800 x 480 with a 4 inch screen, similar to a cell phone.

There are ways to configure the chip fairly easily.? All you need to do is write C code.?

If you can design and make PC boards, then a Nucleo-144 board with a homemade board can drive an LCD display.? You'll have to roll your own software for that, though, since most of the display hardware would not be supported.?

For smaller projects, there's a Nucleo-32 board which has the same form factor as an arduino Nano.? The Nucleo 64 boards (more powerful processor) have an arduino plugin capability.

Harvey

On 11/6/2021 4:33 PM, peter bunge wrote:

I looked at the 1700 page data sheet for the Arm Cortex 32 bit CPU and the much smaller development board data sheet (30 pages?).

It looks complicated!

I have a RaspberryPi 3 inserted in a SmartiPi Touch Case with wireless ISB keyboard. I think it would be easier to use and it has a higher resolution screen. $350 Cdn if I remember correctly.

It may be easier to replace in 5 years time when the ST becomes obsolete.

On Sat, Nov 6, 2021 at 2:36 PM peter bunge via <bunge.pjp=gmail.com@groups.io> wrote:

I am impressed with the video and would love to add an LCD to my HP4192A Impedance Analyzer that has no CRT and expects an XYY analog pen plotter.

Anyone interested please contact me privately and maybe we can do something.

I also have a Tek 576 Curve Tracer but the CRT is good and I have a spare. I can see the advantages of updating it. Keep me in the loop,?I may be able?to contribute.

I updated my HP8753B with the Newscope LCD and am delighted with it. My HP8757C has a colour LCD and is excellent but a bit dim in bright lighting, as is my HP54542C DSO.

Getting a digital screen capture would be great as well. My 3 HP mentioned have ways to get a screen capture (John Miles 7470A emulator, Prologix USB/GPIB, and a USB floppy reader).

What language is the software written in? I am struggling with a decision to learn Python but have pretty well decided to stick to C which I use for programming PICs. Python would be a huge distraction and time burner for me.

Peter

On Sat, Nov 6, 2021 at 12:49 PM green <hrgerson@...> wrote:

hi,

In the event of instrument CRT death, one might want to do a replacement having an LCD display:

The question is:
-- are there any existing modules ( or schematics, or projects )? that might be used for an HP older instrument having an XY (XYZ or Vector) type CRT that would allow replacement of the CTR with an LCD ( & also provide a laptop connection for data manipulation & saving ) ?

This question is for a Vector type XY or XYZ CRT?? found in some older scopes, ... & ? for example the Tek 576 Curve Tracer ( CT ) :

??? {??? Raster type CRT to VGA type modules can be had inexpensively on eBay for ~ $29,etc.? .... and is not the topic in this thread }

There has been some recent discussion about this for the Tek 576 CT on that Groups .io .... without a resolution as of yet,
but the same solution *might* be of use to older HP instruments as well ?

/g/TekScopes/topic/86718765
and
/g/TekScopes/topic/69490299#164207


Anyway, looking for a solution to this XY ( XYZ, Vector )? type CRT to LCD problem.
{ Not wanting to replace the CRT with another CRT ! }

There is an example of someone doing a retrofit add-on LCD module for an HP 141T 18GHz SA:



The individual did not make any further YouTube video upgrades to that project; but it is a start !
The discussed ST LCD module is not too expensive ( $55 to $130 ).


The video Arcade Game folks do have an expensive module that can do this for their Vector type CRT's,
... discussed in the Tek Curve Tracer CRT discussion : /g/TekScopes/topic/86718765
However, this Tempest module ( ~$525 !! ) & the NewScope modules are way too expensive !
-- So, would not be buying those at all !

So, looking for a less expensive module or schematics of such to attempt a DIY for the XY (XYZ or Vector) CRT to LCD replacement.

>> Anyone having specific detailed technical knowledge for an XY (XYZ, Vector) to LCD module, or schematics? to the above issue ?
? would be appreciated.

thank you,
rick

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You don't need to read the entire 1700 page book.? It's useful for finding out exactly what a section does, or if you wish to program in assembly (depending on which 1700 pages).? More important would be the board manual.

Once you start messing with graphics, things can be complicated, but that very much depends on how you do it.? There are drivers available that work on the board, though.?

The one F469I-disco board needs only scaled inputs.? An arduino style breadboard plugged in can likely give you that and you can access the 4 ADC converter inputs and protect the chip with op amp buffers.? The display is 800 x 480 with a 4 inch screen, similar to a cell phone.

There are ways to configure the chip fairly easily.? All you need to do is write C code.?

If you can design and make PC boards, then a Nucleo-144 board with a homemade board can drive an LCD display.? You'll have to roll your own software for that, though, since most of the display hardware would not be supported.?

For smaller projects, there's a Nucleo-32 board which has the same form factor as an arduino Nano.? The Nucleo 64 boards (more powerful processor) have an arduino plugin capability.

Harvey

I looked at the 1700 page data sheet for the Arm Cortex 32 bit CPU and the much smaller development board data sheet (30 pages?).
It looks complicated!

I have a RaspberryPi 3 inserted in a SmartiPi Touch Case with wireless ISB keyboard. I think it would be easier to use and it has a higher resolution screen. $350 Cdn if I remember correctly.
It may be easier to replace in 5 years time when the ST becomes obsolete.
20210509_194618.jpg

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Hello Group!

I'm trying to get a handle on my test gear and decided to start looking at my HP hoard.
I need to decide what to keep/fix/purge/replace and finally joining here seemed like a good first step.

I have at least the following items, maybe more hiding unseen in the various piles:

HP:
- several linear power supplies,
- K04-0980A Powerstat
- a gain phase meter (3575A?)
- 33120A function generator
- 3456A voltmeter
- a pair of 1662AS logic analyzers (with at least one keyboard and one mouse...more I think)
- 8505A vector network analyzer with 8501 storage normalizer and 8503A S-parameter kit

Agilent:
- 1147A scope current probe (for the 3034T 'scope below)
- 34410A multimeter
- and maybe a scope in storage?? I need to check on that.

Keysight:
MSOX-3034T oscilloscope

Tektronix:
- approximately 0.42 container ships full of big iron piled ceiling high in the living room

Random other MFG's:
- a pair of IBM Model M keyboards, one for work and one for home (they count as boat anchors too!)
- generally too much stuff !!!

The immediate goal is to get all of this off the floor and off the benches so I can at least check functionality of everything.
Longer term I want to eliminate redundant gear and fill some holes in the lab and then start playing with stuff again!

Cheers,
-Chris

Be careful when handling the oil in those old bathtub caps. The older
ones are full of PCBs.

Dave Casey

On Sat, Nov 6, 2021 at 1:15 PM Bob Albert via groups.io <bob91343=
yahoo.com@groups.io> wrote:

Regarding reliability of oil filled capacitors, a while back a
friend had the main filter capacitor of an HP410B fail. It
exploded. It was an oil filled bathtub capacitor, maybe 4
microfarads. As luck would have it (and has had it multiple times)
I had an identical part in my stash and except for cleaning up the
mess, it was a simple repair. The new part had a 1947 date code
and was older than the failed one.

Bob

On Saturday, November 6, 2021, 10:41:26 AM PDT, Richard Knoppow <
dickburk@...> wrote:


I absolutely agree with this. However, all paper caps tend to
become degraded with time. The Sprague caps seem to have had a
peculiar problem and short time failures but all old paper caps
should be suspect.
Old oil filled transmitting caps seem to have a longer life
than the wax filled kind. My understanding is that one function
of the oil is to eliminate air which can cause oxidation of the
paper. This may also have been the reason for using a plastic
impregnant. I thought I saw advertising from Sprague saying that
the Black Beauty caps were plastic impregated but was not later
able to find it. The paper looks like it has a coating of something.
I would certainly be interesting to know the manufacturing
process used for these. It may be buried in the literature
somewhere. In any case really old paper caps of any make or type
should probably be replaced.

On 11/6/2021 6:57 AM, Chuck Harris wrote:

Hi Richard,

I have never seen anything that would lead me to believe
an end cap was glued onto the body of the capacitor, but
maybe that is what they did? Or, maybe the capacitor was
built in halves, and the mold line is really a glue line?

Capacitors of all types ultimately boil down to a pair of
plates, with a dielectric fill between them.

If the dielectric sheet does not fill the space fully, it
greatly reduces the effect of the dielectric on the capacitance.
The oil's greatest contribution is in making an intimate
contact with both plates, and eliminating any air between
the plates. This both improves the capacitor's stability,
and its dielectric strength.

All of my speculation is secondary to the message both of
us should be (are) giving:

Replace oil filled BB capacitors on sight!

I know that ASCII art doesn't work well on these lists, but
if you consider this line below a single axial slice of the
capacitor, it shows the important observable characteristics
of BB capacitors:


==========O(|||..||...)==========

The "O" is a solder blob that seals the oil filler tube.
The "==" is the capacitor's leads.
The "(" and ")" are the domed ends of the capacitor's body.
The "|||" are the color bands on the body...
And, the "..." is just the black body.

-Chuck Harris


On Fri, 5 Nov 2021 22:08:12 -0700 "Richard Knoppow"
<dickburk@...> wrote:

I may be wrong about the voltage value, I am going by memory
of the advertising.
I have wondered the same thing about the oil filling. Its
possible the casings were cast and the winding inserted in it. I
don't think the windings were deliberately misshapen but that
might be. I wonder what effect squeezing them would have on the
value. If the spacing remained constant the shape would have
little effect. My own experience in manufacturing is with
precision resistors, I have little idea how capacitors were made.
BTW, the Micamold paper caps seem to have a terrible
reputation. Every one I've encountered was very leaky but they
look find inside. Same with the Solar flat paper caps.
Both of these companies vanished shortly after WW-2, I have
never been able to find out what happened. Solar had space
reserved in an early "Radio's Master" catalog but no entry and
the next issue just was not there.
I've never seen any Micamold caps in -hp- stuff but lots of
Sprague, they must have had something going for them.

On 11/5/2021 9:11 PM, Chuck Harris wrote:

Hi Richard,

Bumble bee was a descriptive name based on the colorful
bands used to indicate the capacitor's value and voltage
rating. It was certainly not a brand name.

Tektronix used numerous 400V oil filled versions of this
capacitor. I replaced several dozen in my 513D, so I am
certain that your statement about the 650V version being
the only oil version is incorrect. The 400V rating is one
of the yellow bands that makes it look like a bumble bee.

Every one that I replaced had the oil filler tube.

I have observed that the capacitor "slug" is smaller than
the cavity that it fits into. It had to be, or they would
not have been able to fill the capacitor with oil from the
tube on the end. How did they make that cavity?

It is my impression that if the slug was misshapen, it most
probably was built that way. Perhaps to keep it from rattling
about in the larger cavity that it fit into.

Excepting where the solder sealed filler tube was damaged during
the capacitor's installation, oil filled BB's lasted a very long
time... easily more than 10 years. The ordinary beeswax dipped
paper capacitors became leaky after a year or two.

-Chuck Harris


On Fri, 5 Nov 2021 15:50:59 -0700 "Richard Knoppow"
<dickburk@...> wrote:

I want to respond to a couple of things in this thread.
First of all, there were other brands of molded paper caps.
None of these had the consistent problems of the Sprague caps
of cracking and actually breaking. Also, I have disected
number of failed plastic caps but don't see the distorted
windings in others. Something went very wrong with these. The
early caps were coded with the JAN striped coding, hence the
name "Bumble Bee". The actual brand name was Black Beauty. The
650V versions were the oil filled ones, lower voltage were not
oil filled. The oil filled caps are often found with the oil
leaked out. The failure seems to be the seal of the filler
tube. The tube was also the lead on one side having a wire
soldered (maybe welded) into it. If the seal is disturbed by,
for instance, excessive soldering temperature, the oil will
leak out. The SP-600 seems to have had an especial problem
with this. Also, the property of dielectric absorption, which
causes a capacitor to retain some charge after being
discharged, can be a problem with timing and low frequency
circuits. One of the few virtues of paper capacitors is low
dielectric absorption. They are a better choice than mica and
much better than HI-K ceramic caps. Plastic film caps,
particularly of certain types have practically no DA and are
the best choice. I don't think the Black Beauty caps were
particularly low in DA but all paper caps are pretty good.
The Black Beauty line was advertised as a long life, high
quality brand. I think Sprague may have fixed the problems with
them eventually but they got a bad reputation quickly.
Hammarlund went to all ceramic caps and at least military
SP-600's were modified to replace all of the paper caps with
ceramic ones. Those are pretty much trouble free.
Whatever happened it caused physical distortion of the
windings of the caps. That could have come from shrinkage of
the case material as it cooled. It seems to be in both the oil
filled and non filled versions, at least the ones I've
dissected. On 11/5/2021 7:25 AM, greenboxmaven via groups.io
wrote:

Thanks for this very good explanation. In addition to the
points you made, I have read the oil fill was often complete,
and hydrostatic force would test the integrety of the plastic.
Shrinkage and loss of resilience of the case would increase
the chance of cracks and leaks. The late 1940s is a
fascinating time in history for me. There was a great deal of
technological progress made, often with over confidence in
new materials and techniques inspired by wartime successes
that performed very well in the short term but lacked long
term reliability. The "Bumble Bee" condensers were excellent
in one regard- they had very little residual charge in the
dielectric after being fully discharged. When used as a
coupling condenser, that can make a difference.

Bruce Gentry, KA2IVY



On 11/5/21 9:38, Chuck Harris wrote:

BB capacitors were molded as well as the technology of the
day would allow... That is not why they cracked.

The problem is the plastic they used, like most plastics,
shrinks slowly over time, and the wire leads, and especially
the solder sealed oil filler tube, that penetrate the
plastic, don't.

This can cause a crack to form at the weakest point, which is
usually at the mold line formed by slight misalignment of the
mold halves.

When you injection mold plastic, the plastic's internal bonds
stretch out to fill the mold. When the plastic cools, it is
frozen into a state where those bonds are stretched.

Over time, under the continuous stress of these stretched
bonds, the plastic will cold flow into a more relaxed
state... becoming slightly smaller.

The problem is if the plastic is constrained by something
inside of it that cannot shrink.... such as the wire leads,
a gear's hub, or an oil filler tube, something has to give.

If the plastic shrinks around a metal tube, the thickest
parts of the plastic will break the thinest parts forming a
crack, and a leak.

I was told by Deane Kidd, that in the early days, Tektronix
created a situation, ripe for failure with BB capacitors, by
putting them tightly fitted into ceramic or bakelite terminal
strips. When the capacitor's leads were soldered, the heat
traveling down the very short leads would melt the
capacitor's solder seal, allowing the oil to mix with the
solder, and make a leak. In the worst cases, the oil would
drool out leaving the capacitor incapable of withstanding
its rated voltage.

Not to mention it made a greasy dirty mess in their otherwise
very nice looking scopes.

-Chuck Harris

On Thu, 4 Nov 2021 14:40:42 -0400 "greenboxmaven via
groups.io" <ka2ivy@...> wrote:

Sprague "Bumble Bee" and "Black Beauty" condensers were
molded improperly, and they will crack, especially the oil
filled ones, and let in moisture. That seems to react with
the oil and make it conductive as well as corrosive. Once
this happens, leakage gets very bad, especially when the
condenser is heated by surrounding components. Many efforts
have been made to bake and otherwise restore them, but once
the problem begins it can not be reversed. The dielectric
charicteristic is perported to be superb for audio
circuits, and AudioPhools will freak out if these
condensers are replaced, that is until the power
transformer, rectifer, output tubes, and filter choke in
their amplifiers are all incinerated. Not only did
Hammarlund use them in receivers, Collins and National did
as well. Tektronix used them in their equipment, and too
many consumer electronics companies to recall all of them.

Bruce Gentry, KA2IVY

On 11/4/21 13:45, Richard Knoppow wrote:

Who made those? Some early advertising for Sprague Black
Beauty caps said they were plasticized paper. The main
problem with these is some sort of production problem they
had. I have dissected a number of "bumble bee" caps, these
are actually Sprague Black Beauty caps with striped value
markigns. I found the windings were distorted. I suspect
this happened during the encapsulation but don't know.
Some of these caps, the higher voltage ones, were oil
impregnated. The oil was introduced through a tube which
formed one of the leads. It is common for all the oil to
have leaked out due to a lack of sealing at the solder
joint between the tube and the lead. That may have been
due to excessive heat when the caps were installed. The
most notorious of the BB caps are those in the Hammarlund
SP-600, however, they were very widely used including in a
lot of -hp- gear. However, in the receiver it is common to
find cracked or split caps or even caps where part of the
casing has come off. I have not seen that in any other
make of equipment. Perhaps just a bad lot or perhaps some
difference in installation. Nonetheless, ALL paper caps
become degraded with age. The usual symptom is an increase
in series resistance. Leakage, which is another term for
parallel resistance, is sometimes a problem but not as
often. I don't think any of these caps, even the real oil
filled transmitting caps, was intended to have a lifetime
of over about ten years. The life problem was known and
described in some engineering texts. It was dependent
partly on voltage; the closer the voltage to the rated
voltage the shorter the life of the cap. Likely it was
some sort of electrolytic degradation of the paper. In any
case, paper caps should be replaced with modern plastic
film caps. These for the most part will last forever and
generally will improve performance perhaps beyond the
original. There is a good amount of information on the web
about the relative merits of various kinds of plastic
dielectrics. Polypropylene seems to be about the best
especially for RF use.

On 11/4/2021 9:33 AM, Dave Wise wrote:

Even the later plasticized-paper “Prokar” and “DiFilm”
versions can cause trouble in some applications – they may
not be leaky, but their Dielectric Absorption and
Dissipation Factor are “through the roof”.

Dave Wise

*From:*HP-Agilent-Keysight-equipment@groups.io
[mailto:HP-Agilent-Keysight-equipment@groups.io] *On
Behalf Of *greenboxmaven via groups.io
*Sent:* Thursday, November 04, 2021 6:25 AM
*To:*HP-Agilent-Keysight-equipment@groups.io
*Subject:* Re: [HP-Agilent-Keysight-equipment] HP200CD
oscillator

ALL Sprague "Black Cat", "Black Beauty" and color striped
"Bumble Bee" condensers should be considered bad on sight.
Unfortunately, they are common in older equipment of all
makes and models. The 630V. polyester condensers are a
fine replacement. The only condensers that are polarized
are electrolytics, poyester condensers are not polarized.

Bruce Gentry, KA2IVY

On 11/4/21 8:51, Richard Merifield wrote:

My unit has Black Cat 0.5MFD 400v axial capacitors
for C8 and C9. Would 630v polyester unpolarised caps be ok
replacements?

--
Richard Knoppow
dickburk@...
WB6KBL