Date   

Re: Historical Analog Scope Triggering Techniques

Harvey White
 

I've used Xilinx, the Coolrunner2 (X2Cxxx) CPLD, and Spartan 3AN, and Spartan 6 FPGAS.  I started out in hardware and switched to software, then went over to systems design.

Vivado, unfortunately, will not (as I understand) any of the above chips, you'll need ISE design suite.  The soft ISP available is somewhat limited, and Xilinx (naturally) wants money for this. (That's on the free versions, I can't afford the more expensive ones).

For a logic analyzer, you are likely to need a trigger recognizer (based on the inputs), to start capture.  You'll need an incrementing counter that stores data into the internal memory. The source for this counter can be either an internal clock (derived from a timebase) or an external clock (state machine). I'd suggest an SPI  interfaced register structure (read/write), which requires something like the spartan 6 (it takes space!) to control the system operation.

I've got such, written in VHDL.  I do have eventual plans to build a logic analyzer, running with an ARM processor, color touchscreen display, and battery powered (I have a fondness for portable equipment).  Same processor/interface could easily support a sensor platform and an IC checker.

Most of the problems I've had are to understand the tools, what some of the equivalences there are between the built in (hardware) primitives and the VHDL itself.  VHDL is somewhat a mixture of Pascal, C++, and Basic.  Not too difficult.

There are some nice designs on opencores which can be used, I did find a very nice SPI interface that can be installed with only a few tweaks.

If you're not doing your own PC boards, buying one that has all the bypass caps and as much I/O as possible is a good idea.  If you can get one with a built in programmer (will be needed!), that's a plus.

Again, the major hardware issue, system wise, is the interface levels.  The Xilinx parts that I use are not 5.0 volt tolerant, so that's a problem to solve.  On an individual pin basis, as long as you're doing 3.3 volt only, you can implement the equivalent of a 6820 parallel I/O port.

It's possible to re-engineer some of the Tektronix digital parts using CPLDs or FPGAs (the more the better) for retrofitting, if that's needed.

Harvey

On 12/4/2020 3:54 PM, Dave Peterson via groups.io wrote:
Caveat: I'm a circuit designer by background. I've been pushing CMOS W&L values around my whole career, so I'm no Verilog/System expert.

However, I am a design engineer at Xilinx and have dabbled a little in our software, Vivado. My understanding is that there is a lot of soft IP that comes included with the SW, including logic analyzers. And when it comes to logic analyzers, I only know that they exist and can guess their purpose and functions to some order. I'll have to take a look at this link above, and this thread gets my head going on possible "projects". For example, they love for us to get to know our products at a user level, and do things like giving us a mini Arduino-like system. Like a Raspberry-PI. I wonder if I can install the above on it. Or look at existing LAs included and see what they can and can't do. But then there's the 23 other "projects" I have going on.

As noted by Tom above: "there is a steep learning curve w.r.t. both the HDL and the toolchain." The system level and toolchain are typically what keep me from getting into this, not the underlying code. Could be fun to bridge the worlds of my past and present.

Dave





Re: Peter Keller book payments PayPal won't release

Roy Thistle
 

On Fri, Dec 4, 2020 at 09:54 AM, Tam Hanna wrote:


everyone misunderstands me at the moment.
Tam, I can safely say, I've never really understood your posts; but, I always read, and enjoy, reading them.
I also did offer to help out, here in the colonies.
Best regards.


Re: Historical Analog Scope Triggering Techniques

Tom Lee
 

Anyone who is willing to dive into the innards of a 465 automatically gets a thumbs up in my book.

--Cheers,
Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 12/4/2020 14:08, Dave Peterson via groups.io wrote:
Aw shucks,
Perhaps you should wait to see if I can recover this old 465 before you go talking me up! Wink.
D.




Re: Historical Analog Scope Triggering Techniques

Dave Peterson
 

Aw shucks,
Perhaps you should wait to see if I can recover this old 465 before you go talking me up! Wink.
D.


Re: Historical Analog Scope Triggering Techniques

Tony Fleming
 

I just wish to have your brain Harvey!
Right now I'm learning a new scope made by Micsig, 100MHz, 4 channels,
touchscreen - here is the base model:
https://www.ebay.com/itm/Micsig-STO1104C-Tablet-Oscilloscope-100MHz-4CH-/254666472743?&hash=item3b4b4dfd27-g-8cAAOSwBRdfBef2&autorefresh=true
I've purchased all the updates and battery + the bag - I like to have
everything, so I don't complain later! ha ha ha
But like anything else, it takes time and repetition with my health
problems, so I'll hope to get it sooner than later, ha ha ha
One of the problems is short term memory, so I've developed a system,
probably works just for me, where I just play with the "new toy" and try to
just have fun. After that I take a break, before frustration sets up and
I'll do something else, like writing emails.
Later I'll return - that is the first day. Day 2 is similar, but I try to
achieve something more "interesting", but only if it is fun.... I'm sure
you get the idea. At one point, if I don't forget a small step somewhere, I
can start using what I've learned. Once it's filed in the more permanent
part of my memory, I can find my ways. But if I don't use the "toys" it
reverts back to learning, but the steps are faster - usually.
On the other hand I can remember details about stuff - my friends call it
"useless", like what we did 35+ years ago, when we all learned programming
and other fun stuff.
Sometimes I think my brain has its own preferences now! It remembers what
it's like, not what I want right now to learn. I should follow my own
advice - when I was IT and teach computers or my new employee to assemble a
new PC! - learn only 1-3 items per day, repeat that next few days before
learning something new! We can sometimes teach others the right way, but I
can't listen to myself!
OK, I hope you had enough comedy from above, I'll return to my retired life
and should stop complaining! ha ha ha
Harvey, you have a great weekend and beautiful Holidays!
Tony

On Fri, Dec 4, 2020 at 11:39 AM Harvey White <madyn@dragonworks.info> wrote:

Thank you.

Many years ago, I was working on TTL stuff with a 513D scope. I needed
to look at multiple traces on a somewhat limited scope. I took the
trigger output (I think), reduced it to a TTL pulse per sweep, ran that
to a binary counter, then to an 8 to 1 multiplexer. The output of that
multiplexer drove a common base summer that used the 4,2 and 1 outputs
from the counter as 8,4 and 2 inputs to a homemade (crude!) D/A
converter with the multiplex output going to the 1 input on that A/D.

Essentially, I got 8 traces time multiplexed onto 1 trace. Worked for
TTL only, but that's what I needed.

Harvey


On 12/4/2020 10:58 AM, Tony Fleming wrote:
Harvey I know this isn't the place to thank you for helping everyone,
but I
wish you Happy Holidays and lots of health & love!
And thanks for helping me with my Tektronix scope!!!
I also like to wish you all Happy Holidays and best 2021!
Let's all love each other!
Let's find common ideas and be willing to listen to others!
Tony

On Fri, Dec 4, 2020 at 9:46 AM Harvey White <madyn@dragonworks.info>
wrote:

That or a CPLD, which has less capability and less cost. They're easier
to use if you're making your own boards, but you'll need a programmer,
so additional cost. Remember that while a CPLD has non volatile memory
for the configuration, most FPGAs don't. That should be included on the
development board, and if you're lucky, so will the programmer. Typical
FPGA downloads a pass through program into the FPGA, uses it to program
the memory, then programs the FPGA from the external memory. That
reprogramming is automatic (or can be) when power is applied to the
board.

You'll want to program in either VHDL or Verilog, although I personally
prefer VHDL.

A critical part of the design is that regardless of CPLD or FPGA, the
I/O voltages are ONLY 3.3 volts, and you *must* level translate. There
are chips good for that, though, and you only need one way.

An arduino, touchscreen display, programming, and some sort of interface
to the CPLD/FPGA would set up triggering conditions. Do note that the
FPGA can support a more complex (I2C or SPI) interface, and THAT needs
to be level translated too.

Nice project.

The simpler design would be some dipswitches, 74LS86, 74LS30. One switch
for 1/0, one switch for "don't care". But where'd be the fun in that?

Harvey


On 12/4/2020 9:30 AM, toby@telegraphics.com.au wrote:
On 2020-12-04 2:31 a.m., Jeff Dutky wrote:
Okay, this is all in line with what I've been thinking about: building
a little box that can raise a TTL output on various conditions like a
specific counter bit, or having a 16 bit input value between two
selected
values, or when certain bits are set or cleared, etc. It seems like this
would make all kinds of things visible on a simple analog scope at
relatively little cost (assuming that you don't want to do the
triggering
at clock rates much above a few tens of MHz, of course).
I would consider a tiny FPGA rather than discrete TTL, which would give
you thousands of gates of logic reconfigurable without soldering. You
can get a suitable dev board for ~ $20.


One of the things that I was trying to do with these scopes, before I
got side tracked having to fix them, was to reverse engineer the digital
interface to a gas plasma display in an old laptop. Getting anything
more
than a very general look at the display signals was very challenging,
especially since I didn't understand most of the scope's features very
well, but also because I just wasn't thinking clearly about how to
trigger
the scope and one what. After working on these scopes for the past
month I
think I'm beginning to get a better feel for what they can do and how
they
should be used.
-- Jeff Dutky


















Re: Historical Analog Scope Triggering Techniques

Tom Lee
 

Will do, definitely! I may be meeting him as soon as next week. If I do, I'll be sure to let him know what a valuable employee he has in his group.

--Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 12/4/2020 13:28, Dave Peterson via groups.io wrote:
Yep,
Tell him you ran into me here. He'll get a kick out of it.
Dave




Re: Historical Analog Scope Triggering Techniques

Dave Peterson
 

Yep,
Tell him you ran into me here. He'll get a kick out of it.
Dave


Re: Historical Analog Scope Triggering Techniques

Tom Lee
 

Hi Dave,

Ah, I see , Vamsi's organization. I hope you're having fun!

-- Cheers,
Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 12/4/2020 13:21, Dave Peterson via groups.io wrote:
Hi Tom,

I'm in CAD now. The current organizational name is CPG (Central Products Group). Building Device Model tooling - the stuff that translates the HW into the SW primitives users work with. I started 9 years ago working on various STA activities for the IO team.

Dave




Re: Historical Analog Scope Triggering Techniques

Dave Peterson
 

Hi Tom,

I'm in CAD now. The current organizational name is CPG (Central Products Group). Building Device Model tooling - the stuff that translates the HW into the SW primitives users work with. I started 9 years ago working on various STA activities for the IO team.

Dave


Re: Historical Analog Scope Triggering Techniques

Tom Lee
 

Hi Dave,

Just out of curiosity, for which group at Xilinx do you work?

-- Cheers,
Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 12/4/2020 12:54, Dave Peterson via groups.io wrote:
Caveat: I'm a circuit designer by background. I've been pushing CMOS W&L values around my whole career, so I'm no Verilog/System expert.

However, I am a design engineer at Xilinx and have dabbled a little in our software, Vivado. My understanding is that there is a lot of soft IP that comes included with the SW, including logic analyzers. And when it comes to logic analyzers, I only know that they exist and can guess their purpose and functions to some order. I'll have to take a look at this link above, and this thread gets my head going on possible "projects". For example, they love for us to get to know our products at a user level, and do things like giving us a mini Arduino-like system. Like a Raspberry-PI. I wonder if I can install the above on it. Or look at existing LAs included and see what they can and can't do. But then there's the 23 other "projects" I have going on.

As noted by Tom above: "there is a steep learning curve w.r.t. both the HDL and the toolchain." The system level and toolchain are typically what keep me from getting into this, not the underlying code. Could be fun to bridge the worlds of my past and present.

Dave




Re: Historical Analog Scope Triggering Techniques

Dave Peterson
 

Caveat: I'm a circuit designer by background. I've been pushing CMOS W&L values around my whole career, so I'm no Verilog/System expert.

However, I am a design engineer at Xilinx and have dabbled a little in our software, Vivado. My understanding is that there is a lot of soft IP that comes included with the SW, including logic analyzers. And when it comes to logic analyzers, I only know that they exist and can guess their purpose and functions to some order. I'll have to take a look at this link above, and this thread gets my head going on possible "projects". For example, they love for us to get to know our products at a user level, and do things like giving us a mini Arduino-like system. Like a Raspberry-PI. I wonder if I can install the above on it. Or look at existing LAs included and see what they can and can't do. But then there's the 23 other "projects" I have going on.

As noted by Tom above: "there is a steep learning curve w.r.t. both the HDL and the toolchain." The system level and toolchain are typically what keep me from getting into this, not the underlying code. Could be fun to bridge the worlds of my past and present.

Dave


Re: Historical Analog Scope Triggering Techniques

Mark Litwack
 

There was an FPGA logic analyzer called the "Open Bench Logic Sniffer" that would make a good multi-purpose trigger accessory for a scope by using its trigger out signal. Along with the usual bit matching, it had an advanced mode which had features found in the old HP 16500 series logic analyzer like 10 trigger terms, 2 range terms, 2 timers, and a 16-level state machine. It operated on up to 32 bits of input.

Unfortunately, it's not available anymore, but the schematics, FPGA Verilog code, and host code to control the advanced trigger are all available if someone wanted to use it as a starting point:

http://dangerousprototypes.com/docs/Open_Bench_Logic_Sniffer

The entry under "v3 Demon core in Verilog" has the details on the advanced triggering capabilities.

-mark


Re: Peter Keller book payments PayPal won't release

Tam Hanna
 

Esteemed quorum,

OK, apparently everyone misunderstands me at the moment. Tried to sort a simple catering (chestnuts for visiting drone airline manager) issue with my wife, ended up in a 2h discussion about cooking, chestnut farming, "tuut" (arab chestnut like fruit) farming, more cooking, inert gases for storing tuut and chestnuts, "tuut" importing and finally her going off like a MiG21 on ROMB mode even though her dread levels are high (please no recommendations re wife management, she is kept in check). All she wanted to know was whether said Drone dude eats Chestnuts.

So, welcome to the club. And yes, it is me - the older I get, the more unclear I become.


To clarify.

_/*Tam acts as INTERMEDIARY and COMMIS. This means: Tilman is waiting for money from Schlomo/Dromo/Omo. Tam pays for the book until Schlomo*/__/*_/*/Dromo/Omo*/_ eventually coughs up.*/_


To the Austrian: I have no connection to the author, and I do not even buy such a book for my own. I could sell you, but could not fulfull such a book to you even if I wanted to. But greet Vienna from me, lived there for many years.


However, I tried to set Peter up with a different publisher. Maybe, I have news to report here soon, but I cannot say anything yet...


All clear now?

Tam



--
With best regards
Tam HANNA

Enjoy electronics? Join 15k7 other followers by visiting the Crazy Electronics Lab at https://www.instagram.com/tam.hanna/


Re: SMD rework/repair. Was: Boston area elecronicsurplus.

Thomas Garson
 

Kerry,

Good info. I used an off the shelf controller purchased from Automation Direct, which worked very well, once I got the hardware properly configured. They have always had what I needed for reasonable prices.

I have put myself in the position where I can build a lot of the electronics I need, but time is always an issue. Often the DIY route takes more valuable time than I can budget in comparison to the cost of a carefully considered, available, off the shelf item.

Where my tools and software really come into play is when I'm constructing custom "one off" or "short run" items or I need something like a build/test fixture for electronics assemblies that I will be having to deal with in multiple instances. Example: I perform upgrades on classic analog audio studio consoles, each of which can have up to several dozen identical modules, all of which must be thoroughly qualified after rework prior to returning to customer. They all have different bus interfaces, including connectors and/or pin arrangements, even within a particular manufacturers catalogue. I can lay out a board and, with my light duty CNC mill, built by adding a 4 axis controller and smallish 3 phase spindle to a Newing-Hall commercial engraver, carve it from copper clad board, all in a few hours.

If I thought there was a viable market, I could design and build stuff like replacement power supply boards for Tek 5000 frames which could be redone using newer components and technology rather than fighting with replacing NLA can capacitors, etc. The problem there is that the market would mostly be folks like those on this list who love their old stuff and would rather take the time to do the repair and keep their 'scope as original as possible, not to mention limit the financial impact.

Thomas Garson
Aural Technology, Ashland, OR
By my calculation, the dynamic range of the universe is roughly 679dB,
which is approximately 225 bits, collected at a rate 1.714287514x10^23 sps.

On 11/30/20 5:16 PM, Kerry Burns wrote:
There was a DIY reflow PID controller published in the April/May 2020 Silicon Chip Magazine (https://www.siliconchip.com.au/Issue/Browse/Issues ).  I haven’t tried building it, but it seems like a reasonable design.
Kerry
From: <TekScopes@groups.io> on behalf of Thomas Garson <tgarson@auraltek.com>
Reply to: <TekScopes@groups.io>
Date: Tuesday, 1 December 2020 at 11:27 am
To: <TekScopes@groups.io>
Subject: [TekScopes] SMD rework/repair. Was: Boston area elecronicsurplus.
I do SMD rework/repair, on occasion. I determined that a reflow oven was
frequently required as solder connection quality/failure were not
infrequent issues.
I built one based on a modified toaster-oven into which I fitted a PID
controller. It was a PITA to do, but is (now: See below.) much better
than the overpriced low quality available options.
Warning:
If rolling your own reflow oven is in the cards, make sure the
thermocouple is located in the upper area of the chamber and is naked.
Do not use an enclosed probe because the response time is too slow. I
did, and cooked the first board I used it on (fortunately not a
customers board). Perhaps the toaster-oven I chose had too much power
compared to a "factory" reflow oven. A lower power oven might have been
a good choice but I wanted one that had a large chamber. It might be a
good idea to determine the temperature rise and cooling rates of your
oven candidate prior to wiring up the heating elements, using fewer if
they are overkill. You might have to add a cooling fan to the enclosure
to assure proper cooling rate after the solder flow temperature is
reached. A lot of parts don't like to spend much time at the solder flow
temperature. If you use a convection oven, it might be possible to
modify the fan shroud to pull in outside (cooler) air.
For sure, there are high quality industrial grade reflow ovens
available, but at too steep a price for my budget.
Thomas Garson
Aural Technology, Ashland, OR
By my calculation, the dynamic range of the universe is roughly 679dB,
which is approximately 225 bits, collected at a rate 1.714287514x10^23 sps.
On 11/30/20 2:47 PM, Shirley Dulcey KE1L wrote:
Sadly, nearly all of those Boston area stores are gone. You-Do-It
Electronics is still open; it now has a significant selection of maker
stuff from Sparkfun and Velleman (and a few Adafruit items) along with the
usual TV repair parts, enclosures, cables, and so forth. Oddly, they
haven't embraced SMD technology at all; they don't even have rework
stations or solder paste. I guess their primary customer base doesn't do
any SMD repair; those boards are considered unrepairable at this point.
On Mon, Nov 30, 2020 at 5:03 PM stevenhorii <sonodocsch@gmail.com> wrote:
I never did get to Meshna's place or B&F but I bought stuff from both via
mail order (the forerunner of online shopping). I think it was a WW
II passive infrared night vision unit I got from Meshna - I could be wrong.
Years later, I discovered that the technology for that wound up being a
fundamental patent that evolved into the first replacement for x-ray film;
storage phosphor plates that stored the x-ray "image" as electron
metastable states in a phosphor layer. Hitting the plate with a scanned
laser would push the electrons out of their metastable state and they would
drop down to ground state giving off light photons as they did so. A
photomultiplier would digitize the intensity of that emission thus was born
the photostimulable phosphor plate radiography system. The story is that
Kodak had the patents for the phosphor system but did not want to kill off
their x-ray film business, so they sold the patents (or licensed them) to
Fuji Medical (the Fuji film people). Fuji Medical produced the first
clinically used phosphor plate radiographic system. The use of x-ray film
declined very rapidly after that.
The last item I bought from B&F when I think it was just Frank Fink was
running the business - it was a militarized DEC PDP-11 built by Norden
Systems under license from DEC. I still have that thing - two two aircraft
avionics type boxes, a mess of cables, and the "control box". A bonus - all
the schematics. It was some version that I think had been used for software
and peripherals development as it runs on 115VAC 60Hz instead of 400Hz. It
runs or at least powers up with no smoke. The control box has two switches
on it - not the nice PDP-11 panel with all the flashing lights and
switches. It basically says "Run" and "Halt". That's it. I found the core
memory modules (they had been removed from the unit I bought) at a hamfest
(the one that used to be in Gaithersburg, MD) and installed them. If there
was any programming left in them, it didn't run so far as I know.
Interfaces are in the form of multipin mil-spec connectors - very expensive
to find mates for.
I used to go to Ron Baublitz's US Surplus in Baltimore. Four floors of a
huge amount of stuff. I think US Surplus may still be around, but they sold
off the building. It was across the street from the B&O Railroad museum. I
also went to Bid-Service in Asbury Park, NJ. It has transformed into a
business that sells used semiconductor fab equipment and are now in
Freehold. It is, I believe, run by the same family that ran the old
Bid-Service run by Bill Cusa. I first met Bill when I had him pick up a lot
for me that I won on a DoD surplus sale. I then drove down to his place to
pick the stuff up and he asked if I wanted to see the stuff he had in his
warehouse. He had started as a business selling used restaurant equipment,
but since he had the trucks, he branched out into the pickup and ship
business for bidders on DoD and GSA sales (hence the name). His initial
inventory came from the packer-shipper business. Often bidders would win a
lot, but only wanted one item. They would often tell Bill he could keep the
rest or at least offer it to him if he'd discount his pickup fee. As a
result, he had a large amount of stuff from those DoD sales. He hired some
guys (one of them his son) who quickly learned about test equipment and
they started bidding on local auctions and sales themselves. I once went in
on a bid with Bill on a complete radiographic/fluoroscopic system being
excessed from the West Point clinic. We won the lot, but my advice to him
was to sell it to a medical remarketer as we did not want the liability or
FDA issues. We still made money - that system was a top-end one that was
still being sold by the manufacturer.
There was another surplus dealer south of Baltimore. I don't remember the
business name, but the owner was Gary Green. Another huge place full of
stuff. You could get all manner of test equipment (yes, including Tek
scopes and plug-ins). Bargains were large mil-spec transit cases - the
large, weather-tight Hardigg ones. Any color you wanted as long as it was
olive drab. Not exactly true - there were white ones also. I was only there
once, but spent the whole day. I bought a Efratom rubidium frequency
standard - worked when I got it. I have not needed it in a while, but I
still have it.
When I think about it, I spent a LOT of weekends climbing around piles of
surplus, or walking through miles of storage racks full of stuff. I used to
have dreams about going to surplus stores and finding something exotic.
Always disappointed to wake up and find it had been a dream!
Steve H.
On Mon, Nov 30, 2020 at 4:17 PM Dick <w1ksz@outlook.com> wrote:
There was also Electro-Craft on Dorchester Ave (in Dorchester).
Tons of NIB ARC-5 Receivers and Transmitters.
73, Dick, W1KSZ
"Dahchester" Boy, 1940-1966
________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of Brad
Thompson <brad.thompsonaa1ip@gmail.com>
Sent: Monday, November 30, 2020 2:13 PM
To: TekScopes@groups.io <TekScopes@groups.io>
Subject: OT: Boston-area electronicsurplus (was:Re: [TekScopes] Fair
Radio
Sales Lima Ohio)
tekscopegroup@miwww.com wrote on 11/30/2020 12:28 PM:
I recall walking Canal Street in lower Manhattan in 1976 during a
vacation trip with my parents.
<snip>
Hello--
Sometime in the early 1960 , my roommate and I hitchhiked from Boston to
his home near Suffern, NY-- his goal was to see his girl friend, and my
goal was
to visit Radio Row in NYC. I didn't have much spare cash and I don't
recall buying
anything <:. I do recall visiting Barry Radio at 512 Broadway, IIRC.
Construction
of the World Trade Center was on the horizon and the surplus stores were
beginning to close.
Fast-forward to the late 1960s-- I had graduated from college and had a
job in
Bedford, MA and a little more spare cash. On a typical Saturday, I could
drive
into Cambridge and visit Heffron's surplus junk yard. From there, I'd
head north to Rte. 128 and stop in Wakefield to shop at Poly-Paks ("We
bot <sic> thousands,
no time to test!") (*)
From there, Meshna's surplus in Lynn was always worth a stop, and on
one occasion
I was invited to visit the warehouse's basement-- filled with
boxes of surplus stacked from floor to ceiling and threaded
with shoulder-wide paths (think, 'mouse trails through a meadow').
There's still gas in the tank and cash in my wallet, and B+F Electronics
near Salem (?)
was my next stop. (B + F were Pete (?) Boniface and Frank Fink).
Finally, there was a four-story brick warehouse near Newburyport. MA,
which wouldstill had glass in most of its windows. On one occasion,
I reached into a box of miscellaneous parts and pulled out a skinny white
cylindrical object. Closer investigation revealed the remainder of the
pigeon skeleton.
Time to go home.
There were a few conventional electronics shops that sometimes offered
surplus
parts-- Abbott Electronics in Woburn, and a shop that moved into Malden
from Atlantic Avenue in downtown Boston. Radio Shack's store on
Commonwealth
Avenue could offer an occasional bargain.
Further out in the suburbs, You-Do-It electronics sold little in the way
of surplus
but was the go-to site for unmolested components. Herbert Gordon (W1IBY
(SK))
sold used ham gear and surplus in Harvard, MA, and offered opinions.
I apologize for omissions and errors of location-- fifty years of recall
imposes a layer of haze on some memories.
73--
Brad AA1IP
(*) In practice, it was possible to buy functional components there, but
sorting through a batch of Transitron rejects and testing them
was very educational.


Re: Historical Analog Scope Triggering Techniques

Harvey White
 

Thank you.

Many years ago, I was working on TTL stuff with a 513D scope.  I needed to look at multiple traces on a somewhat limited scope.  I took the trigger output (I think), reduced it to a TTL pulse per sweep, ran that to a binary counter, then to an 8 to 1 multiplexer.  The output of that multiplexer drove a common base summer that used the 4,2 and 1 outputs from the counter as 8,4 and 2 inputs to a homemade (crude!) D/A converter with the multiplex output going to the 1 input on that A/D.

Essentially, I got 8 traces time multiplexed onto 1 trace. Worked for TTL only, but that's what I needed.

Harvey

On 12/4/2020 10:58 AM, Tony Fleming wrote:
Harvey I know this isn't the place to thank you for helping everyone, but I
wish you Happy Holidays and lots of health & love!
And thanks for helping me with my Tektronix scope!!!
I also like to wish you all Happy Holidays and best 2021!
Let's all love each other!
Let's find common ideas and be willing to listen to others!
Tony

On Fri, Dec 4, 2020 at 9:46 AM Harvey White <madyn@dragonworks.info> wrote:

That or a CPLD, which has less capability and less cost. They're easier
to use if you're making your own boards, but you'll need a programmer,
so additional cost. Remember that while a CPLD has non volatile memory
for the configuration, most FPGAs don't. That should be included on the
development board, and if you're lucky, so will the programmer. Typical
FPGA downloads a pass through program into the FPGA, uses it to program
the memory, then programs the FPGA from the external memory. That
reprogramming is automatic (or can be) when power is applied to the board.

You'll want to program in either VHDL or Verilog, although I personally
prefer VHDL.

A critical part of the design is that regardless of CPLD or FPGA, the
I/O voltages are ONLY 3.3 volts, and you *must* level translate. There
are chips good for that, though, and you only need one way.

An arduino, touchscreen display, programming, and some sort of interface
to the CPLD/FPGA would set up triggering conditions. Do note that the
FPGA can support a more complex (I2C or SPI) interface, and THAT needs
to be level translated too.

Nice project.

The simpler design would be some dipswitches, 74LS86, 74LS30. One switch
for 1/0, one switch for "don't care". But where'd be the fun in that?

Harvey


On 12/4/2020 9:30 AM, toby@telegraphics.com.au wrote:
On 2020-12-04 2:31 a.m., Jeff Dutky wrote:
Okay, this is all in line with what I've been thinking about: building
a little box that can raise a TTL output on various conditions like a
specific counter bit, or having a 16 bit input value between two selected
values, or when certain bits are set or cleared, etc. It seems like this
would make all kinds of things visible on a simple analog scope at
relatively little cost (assuming that you don't want to do the triggering
at clock rates much above a few tens of MHz, of course).
I would consider a tiny FPGA rather than discrete TTL, which would give
you thousands of gates of logic reconfigurable without soldering. You
can get a suitable dev board for ~ $20.


One of the things that I was trying to do with these scopes, before I
got side tracked having to fix them, was to reverse engineer the digital
interface to a gas plasma display in an old laptop. Getting anything more
than a very general look at the display signals was very challenging,
especially since I didn't understand most of the scope's features very
well, but also because I just wasn't thinking clearly about how to trigger
the scope and one what. After working on these scopes for the past month I
think I'm beginning to get a better feel for what they can do and how they
should be used.
-- Jeff Dutky













Re: I give up.

-
 

Maybe you haven't been reading the messages but Dennis has already been
paid and that's all taken care of. But I have to admit that I hadn't
considered a wire transfer INTO PayPal. I've never heard of that being done
and there's nothing about it on their website and I don't even know if it's
possible. I don't think that it is but perhaps.

I was talking about the potential problems of PayPal and other
companies involved in E-commerce. And you can't deny that those are real.
All you have to do is to read any newspaper or watch any TV news to know
that major data thefts are happening almost daily. And your 20 years is
nothing, that was when Windows 98 was still new. I beta tested Windows
1.1! I started programming in 1969 in APL on an IBM 1130 and had been
tinkering with computer hardware for two years before that. I was the
person that installed *the* first computers for the Gallup poll in New
Jersey (another IBM 1130 with added core memory) , Virginia Military
Institute and Washington and Lee university and a host of others back in
the mid-1970s.

On Fri, Dec 4, 2020 at 9:10 AM cheater cheater <cheater00social@gmail.com>
wrote:

Paying with paypal from credit card is simpler, but doesn't work in this
case, so you're supposed to do the next simplest thing, which is top up via
wire transfer and then pay from balance. All this hacked companies paranoia
is seriously too much, and I say that as a cyber security expert who has
been professionally in IT for 20 years. I've seen and responded to
countless hacks and I know good security awareness is necessary. You're
talking about your bank and about paypal. If either of them get hacked then
you have much larger problems than whether or not you have the convenience
of being a git towards Dennis. Have it from the horse's mouth: you're not
being aware of potential problems, you're being unreasonably paranoid, and
you're cargo-culting security obviously without understanding any of it.
Stop it and just pay Dennis without dragging your feet.

On Fri, Dec 4, 2020 at 3:58 AM - <rrrr6789@gmail.com> wrote:

It's much simpler to just pay via PP and have them charge my credit card,
then there's never a balance in my PayPal account and if I haven't
linked a
bank account to your PP account then they can't debit it either. A credit
card also has much better protection and you also have legal recourse if
things go wrong. These days, it isn't just PayPal that you have to worry
about, plenty of companies have been hacked and their client's data
stolen.
The fewer companies that are linked and the fewer that have any of your
information including information about your other accounts, the safer
you
are.

On Thu, Dec 3, 2020 at 12:05 PM cheater cheater <
cheater00social@gmail.com
wrote:

Right, that's why you top it up with the amount you want to pay, and
then
pay. You don't carry a balance - you top up, then pay immediately.
Unless
you're some sort of criminal with an international warrant on your
head,
money will not disappear from your account within one day. There's a
certain amount of paranoia that's healthy with online services, but
there
are limits to reasonable application of that as well.

On Thu, Dec 3, 2020 at 1:53 AM - <rrrr6789@gmail.com> wrote:

George, It's already taken care of.


Cheater, FWIW I don't know anyone that carries a balance in their PP
account. Not only does PP not pay interest, but PP has been known to
yank
money back out of their customer's accounts without warning so
everyone
that I know takes their money out of PP as soon as possible. Yes. I
know
that PP can also yank money out of their customer's bank accounts as
well.
Most people keep only a minimum amount in their linked accounts for
that
reason and keep their main bank account in a different bank entirely.

On Wed, Dec 2, 2020 at 9:11 AM George Onufer <amatec@att.net> wrote:

Mr. RigdonI am so sorry to hear of the tribulations you have
endured
in
trying to buy these books.Dennis took on this task (beyond the
resposibility he already had as moderator) out of his respect and
sense
of
duty to the group. He established ground rules to make it
manageable
for
himself. If, for whatever reason, these don't work for you, then
by
all
means he should make a special exception in your case.GeorgeSent
from
my
T-Mobile 4G LTE Device





















Re: Peter Keller book payments PayPal won't release

-
 

I don't think that anyone "wanted" any such thing. Tam merely offered to
buy some of the extra copies so that Dennis wouldn't be stuck with them.
But on the other hand, it is the author's intent to sell as many copies as
possible so Tam's offer is consistent with that.

On Fri, Dec 4, 2020 at 9:12 AM cheater cheater <cheater00social@gmail.com>
wrote:

So let me get this clear, in case someone doesn't come through, you want to
buy off the extra books, and hoard them? This re-print was meant for people
who actually want to read those books. It wasn't meant for the collectors
who ramped up the originals to insane prices.

On Fri, Dec 4, 2020 at 3:55 AM Tam Hanna <tamhan@tamoggemon.com> wrote:

Hello Damian,

sorry, but I do not sell these at all.


I only wanted to offer my services as a "bank" to ease Tilmans work load.


Tam

--
- - - - -
With best regards
Tam HANNA

Enjoy electronics? Join 13500 followers by visiting the Crazy Electronics
Lab at https://www.instagram.com/tam.hanna/











Re: Historical Analog Scope Triggering Techniques

Tony Fleming
 

Harvey I know this isn't the place to thank you for helping everyone, but I
wish you Happy Holidays and lots of health & love!
And thanks for helping me with my Tektronix scope!!!
I also like to wish you all Happy Holidays and best 2021!
Let's all love each other!
Let's find common ideas and be willing to listen to others!
Tony

On Fri, Dec 4, 2020 at 9:46 AM Harvey White <madyn@dragonworks.info> wrote:

That or a CPLD, which has less capability and less cost. They're easier
to use if you're making your own boards, but you'll need a programmer,
so additional cost. Remember that while a CPLD has non volatile memory
for the configuration, most FPGAs don't. That should be included on the
development board, and if you're lucky, so will the programmer. Typical
FPGA downloads a pass through program into the FPGA, uses it to program
the memory, then programs the FPGA from the external memory. That
reprogramming is automatic (or can be) when power is applied to the board.

You'll want to program in either VHDL or Verilog, although I personally
prefer VHDL.

A critical part of the design is that regardless of CPLD or FPGA, the
I/O voltages are ONLY 3.3 volts, and you *must* level translate. There
are chips good for that, though, and you only need one way.

An arduino, touchscreen display, programming, and some sort of interface
to the CPLD/FPGA would set up triggering conditions. Do note that the
FPGA can support a more complex (I2C or SPI) interface, and THAT needs
to be level translated too.

Nice project.

The simpler design would be some dipswitches, 74LS86, 74LS30. One switch
for 1/0, one switch for "don't care". But where'd be the fun in that?

Harvey


On 12/4/2020 9:30 AM, toby@telegraphics.com.au wrote:
On 2020-12-04 2:31 a.m., Jeff Dutky wrote:
Okay, this is all in line with what I've been thinking about: building
a little box that can raise a TTL output on various conditions like a
specific counter bit, or having a 16 bit input value between two selected
values, or when certain bits are set or cleared, etc. It seems like this
would make all kinds of things visible on a simple analog scope at
relatively little cost (assuming that you don't want to do the triggering
at clock rates much above a few tens of MHz, of course).
I would consider a tiny FPGA rather than discrete TTL, which would give
you thousands of gates of logic reconfigurable without soldering. You
can get a suitable dev board for ~ $20.


One of the things that I was trying to do with these scopes, before I
got side tracked having to fix them, was to reverse engineer the digital
interface to a gas plasma display in an old laptop. Getting anything more
than a very general look at the display signals was very challenging,
especially since I didn't understand most of the scope's features very
well, but also because I just wasn't thinking clearly about how to trigger
the scope and one what. After working on these scopes for the past month I
think I'm beginning to get a better feel for what they can do and how they
should be used.

-- Jeff Dutky













Re: Historical Analog Scope Triggering Techniques

Tom Gardner
 

On 04/12/20 14:30, toby@telegraphics.com.au wrote:
On 2020-12-04 2:31 a.m., Jeff Dutky wrote:
Okay, this is all in line with what I've been thinking about: building a little box that can raise a TTL output on various conditions like a specific counter bit, or having a 16 bit input value between two selected values, or when certain bits are set or cleared, etc. It seems like this would make all kinds of things visible on a simple analog scope at relatively little cost (assuming that you don't want to do the triggering at clock rates much above a few tens of MHz, of course).
I would consider a tiny FPGA rather than discrete TTL, which would give
you thousands of gates of logic reconfigurable without soldering. You
can get a suitable dev board for ~ $20.
That can work, but there is a steep learning curve w.r.t. both the HDL and the toochain.

A logic analyser is simpler, cheaper, less to implement. Use both hammers and screwdrivers :)


Re: Historical Analog Scope Triggering Techniques

Harvey White
 

That or a CPLD, which has less capability and less cost.  They're easier to use if you're making your own boards, but you'll need a programmer, so additional cost.  Remember that while a CPLD has non volatile memory for the configuration, most FPGAs don't.  That should be included on the development board, and if you're lucky, so will the programmer.  Typical FPGA downloads a pass through program into the FPGA, uses it to program the memory, then programs the FPGA from the external memory.  That reprogramming is automatic (or can be) when power is applied to the board.

You'll want to program in either VHDL or Verilog, although I personally prefer VHDL.

A critical part of the design is that regardless of CPLD or FPGA, the I/O voltages are ONLY 3.3 volts, and you *must* level translate.  There are chips good for that, though, and you only need one way.

An arduino, touchscreen display, programming, and some sort of interface to the CPLD/FPGA would set up triggering conditions.  Do note that the FPGA can support a more complex (I2C or SPI) interface, and THAT needs to be level translated too.

Nice project.

The simpler design would be some dipswitches, 74LS86, 74LS30. One switch for 1/0, one switch for "don't care".  But where'd be the fun in that?

Harvey

On 12/4/2020 9:30 AM, toby@telegraphics.com.au wrote:
On 2020-12-04 2:31 a.m., Jeff Dutky wrote:
Okay, this is all in line with what I've been thinking about: building a little box that can raise a TTL output on various conditions like a specific counter bit, or having a 16 bit input value between two selected values, or when certain bits are set or cleared, etc. It seems like this would make all kinds of things visible on a simple analog scope at relatively little cost (assuming that you don't want to do the triggering at clock rates much above a few tens of MHz, of course).
I would consider a tiny FPGA rather than discrete TTL, which would give
you thousands of gates of logic reconfigurable without soldering. You
can get a suitable dev board for ~ $20.


One of the things that I was trying to do with these scopes, before I got side tracked having to fix them, was to reverse engineer the digital interface to a gas plasma display in an old laptop. Getting anything more than a very general look at the display signals was very challenging, especially since I didn't understand most of the scope's features very well, but also because I just wasn't thinking clearly about how to trigger the scope and one what. After working on these scopes for the past month I think I'm beginning to get a better feel for what they can do and how they should be used.

-- Jeff Dutky







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