Apollo AGC backplane simulator

"Tim Williams" <tiwill@seventransistorlabs.com> wrote in
news:qh5v6l$10e$1@dont-email.me:

"John Larkin" <jjlarkin@highland_snip_technology.com> wrote in
message news:ugsbjehk740d4na4d72iegss0aidm6qoto@4ax.com...
What is the impedance of a wire-wrap wire? How repeatable is it?

Easy. 100-150 ohms.

Assuming a close-by ground plane, which is a necessity for
anything of more than minuscule scale.

Not bad considering a proto PCB is +/- 20%. More than good enough
for TTL. They used twisted pair wire wraps for ECL backplanes, too
(which would be closer to 100 ohms all the time).

The crosstalk is the worse problem.

Tim

Go to google images and pump "12 minute mandelbrot" into the search
field. A bunch os computer hdw pics and fractals come up.

They used a 50 year old mainframe to make fractals and it was wire
wrapped tech.

 

DecadentLinuxUserNumeroUno@decadence.org wrote in
news:qh98sn$fr3$1@gioia.aioe.org:

"Tim Williams" <tiwill@seventransistorlabs.com> wrote in
news:qh5v6l$10e$1@dont-email.me:

"John Larkin" <jjlarkin@highland_snip_technology.com> wrote in
message news:ugsbjehk740d4na4d72iegss0aidm6qoto@4ax.com...
What is the impedance of a wire-wrap wire? How repeatable is it?

Easy. 100-150 ohms.

Assuming a close-by ground plane, which is a necessity for
anything of more than minuscule scale.

Not bad considering a proto PCB is +/- 20%. More than good
enough for TTL. They used twisted pair wire wraps for ECL
backplanes, too (which would be closer to 100 ohms all the time).

The crosstalk is the worse problem.

Tim


Go to google images and pump "12 minute mandelbrot" into the
search
field. A bunch os computer hdw pics and fractals come up.

They used a 50 year old mainframe to make fractals and it was
wire
wrapped tech.

Some nice, smart dude's blog.

<http://www.righto.com/2015/03/12-minute-mandelbrot-fractals-on-
50.html>

 

DecadentLinuxUserNumeroUno@decadence.org wrote in news:qh99ff$j4k$1
@gioia.aioe.org:

snip

Some nice, smart dude's blog.

http://www.righto.com/2015/03/12-minute-mandelbrot-fractals-on-
50.html

Oh, and I noticed also that no one in the group even mentioned the
death of Chris Kraft on the 22nd.

Oh that's right... everyone here thinks the space program is a
waste.

 

On Mon, 22 Jul 2019 10:38:57 -0700, John Larkin
<jjlarkin@highland_snip_technology.com> wrote:

On Mon, 22 Jul 2019 09:58:57 -0700 (PDT), Lasse Langwadt Christensen
langwadt@fonz.dk> wrote:

mandag den 22. juli 2019 kl. 18.45.04 UTC+2 skrev John Larkin:
On Mon, 22 Jul 2019 09:27:51 -0700 (PDT), Klaus Kragelund
klauskvik@hotmail.com> wrote:

Wirewrap is a stable gas tight connection. I am seriously considering it for a new design

Cost is super cheap, only high investment in robotics

It's terrible for fast stuff, and can be flakey. Are wires still
gas-tight after they break?

It's not cheap! PCBs are cheap.

Optimizing wire-wrap is the "traveling salesman" problem. I've written
programs to re-order wire-wrap lists to approximately minimize total
wire length. Never again!

how is that different from a PCB?

For one thing, wire-wrap doesn't have power pours!

It certainly can. Augat used to sell standardized panels with power
on one side and ground on the other. Some had the corners connected
and others used things that looked like 0.100" bobby pins, soldered
around the WW socket pin to connect to the pour. They worked
exceedingly well. I used them up to about 50MHz.

A PCB can make a tee or plop a via anywhere; it doesn't need a post to
make a junction. That is not the traveling salesman problem, or the
wire-wrap problem, which have fixed nodes.

Which, of course is horrible for speed, which you were just
complaining about.

I recall only being able to make two automatic wraps on a post, so a
node was topologically one long string. A PCB has no such constraints.

There were 3-level pins, as well. Long strings are better, in any
case.

DEC's early PDP-11 boxes used a wire-wrap backplane for the unibus. It
was a slow signal-integrity nightmare. It was shocking that they would
do something so stupid.

IBM used WW for board backplanes, as well. Worked really well, though
they were also printed and multi-layer.

>What is the impedance of a wire-wrap wire? How repeatable is it?

100-ohms, with teflon wire, anyway. Not bad at all. The more random
the wiring the better the impedance.

 

On Tue, 23 Jul 2019 20:32:28 -0400, Martin Riddle
<martin_ridd@verizon.net> wrote:

On Mon, 22 Jul 2019 12:14:44 -0700, John Larkin
jjlarkin@highland_snip_technology.com> wrote:

On Mon, 22 Jul 2019 21:42:58 +0300, upsidedown@downunder.com wrote:

On Mon, 22 Jul 2019 08:28:38 -0700, John Larkin
jjlarkin@highlandtechnology.com> wrote:

On Mon, 22 Jul 2019 15:18:55 +0000 (UTC),
DecadentLinuxUserNumeroUno@decadence.org wrote:

This would be a good app to have for examining netlist connections

http://apolloguidance.computer/2003100_071/pins

We used to do wire-wrap backplanes and boards. It was horrible.

And to make things even worse, all wire wraps were single color


No, we used colors for manually wrapped things. Not full auto.

Does anybody still use wire-wrap?

I use wire-wrap wire, but not for wire wrapping.

I find that the #30 Kynar wire is great for reworking SMT boards.

I prefer Teflon wire, though I've switched from #30 to #32 wire
(because I can't find smaller). #30 wire is huge compared to 0402s
and QFP leads, for instance.

 

[Tauno Voipio]

On 25.7.19 05:20, krw@notreal.com wrote:

On Mon, 22 Jul 2019 10:38:57 -0700, John Larkin
jjlarkin@highland_snip_technology.com> wrote:

On Mon, 22 Jul 2019 09:58:57 -0700 (PDT), Lasse Langwadt Christensen
langwadt@fonz.dk> wrote:

mandag den 22. juli 2019 kl. 18.45.04 UTC+2 skrev John Larkin:
On Mon, 22 Jul 2019 09:27:51 -0700 (PDT), Klaus Kragelund
klauskvik@hotmail.com> wrote:

Wirewrap is a stable gas tight connection. I am seriously considering it for a new design

Cost is super cheap, only high investment in robotics

It's terrible for fast stuff, and can be flakey. Are wires still
gas-tight after they break?

It's not cheap! PCBs are cheap.

Optimizing wire-wrap is the "traveling salesman" problem. I've written
programs to re-order wire-wrap lists to approximately minimize total
wire length. Never again!

how is that different from a PCB?

For one thing, wire-wrap doesn't have power pours!

It certainly can. Augat used to sell standardized panels with power
on one side and ground on the other. Some had the corners connected
and others used things that looked like 0.100" bobby pins, soldered
around the WW socket pin to connect to the pour. They worked
exceedingly well. I used them up to about 50MHz.

A PCB can make a tee or plop a via anywhere; it doesn't need a post to
make a junction. That is not the traveling salesman problem, or the
wire-wrap problem, which have fixed nodes.

Which, of course is horrible for speed, which you were just
complaining about.

I recall only being able to make two automatic wraps on a post, so a
node was topologically one long string. A PCB has no such constraints.

There were 3-level pins, as well. Long strings are better, in any
case.

DEC's early PDP-11 boxes used a wire-wrap backplane for the unibus. It
was a slow signal-integrity nightmare. It was shocking that they would
do something so stupid.

IBM used WW for board backplanes, as well. Worked really well, though
they were also printed and multi-layer.

What is the impedance of a wire-wrap wire? How repeatable is it?

100-ohms, with teflon wire, anyway. Not bad at all. The more random
the wiring the better the impedance.

Wire-wrap was pretty normal for the computer backplanes of the
1960's and 1970's. Often the regular bus lines were circuit board
foils and the non-regular lines wire-wrapped on the connector pins.

One of the larger computers of the era using the hybrid backplane
as the Univac 1108.

--

-TV

 

[John Larkin]

On Wed, 24 Jul 2019 22:20:55 -0400, krw@notreal.com wrote:

On Mon, 22 Jul 2019 10:38:57 -0700, John Larkin
jjlarkin@highland_snip_technology.com> wrote:

On Mon, 22 Jul 2019 09:58:57 -0700 (PDT), Lasse Langwadt Christensen
langwadt@fonz.dk> wrote:

mandag den 22. juli 2019 kl. 18.45.04 UTC+2 skrev John Larkin:
On Mon, 22 Jul 2019 09:27:51 -0700 (PDT), Klaus Kragelund
klauskvik@hotmail.com> wrote:

Wirewrap is a stable gas tight connection. I am seriously considering it for a new design

Cost is super cheap, only high investment in robotics

It's terrible for fast stuff, and can be flakey. Are wires still
gas-tight after they break?

It's not cheap! PCBs are cheap.

Optimizing wire-wrap is the "traveling salesman" problem. I've written
programs to re-order wire-wrap lists to approximately minimize total
wire length. Never again!

how is that different from a PCB?

For one thing, wire-wrap doesn't have power pours!

It certainly can. Augat used to sell standardized panels with power
on one side and ground on the other. Some had the corners connected
and others used things that looked like 0.100" bobby pins, soldered
around the WW socket pin to connect to the pour. They worked
exceedingly well. I used them up to about 50MHz.

A PCB can make a tee or plop a via anywhere; it doesn't need a post to
make a junction. That is not the traveling salesman problem, or the
wire-wrap problem, which have fixed nodes.

Which, of course is horrible for speed, which you were just
complaining about.

I control impedances and terminations on a PCB. I can have a 50 ohm
trace that splits into two 100 ohm traces. Wire-wrap can't do that.

Wire-wrap was expensive and barbaric, which is why hardly anyone uses
it any more. It was sorta usable for breadboarding, back when we used
DIP ic's in sockets. I don't miss any of that.

The really good thing nowadays is quick-turn, cheap multilayer PCBs
for prototyping.

I recall only being able to make two automatic wraps on a post, so a
node was topologically one long string. A PCB has no such constraints.

There were 3-level pins, as well. Long strings are better, in any
case.

DEC's early PDP-11 boxes used a wire-wrap backplane for the unibus. It
was a slow signal-integrity nightmare. It was shocking that they would
do something so stupid.

IBM used WW for board backplanes, as well. Worked really well, though
they were also printed and multi-layer.

What is the impedance of a wire-wrap wire? How repeatable is it?

100-ohms, with teflon wire, anyway. Not bad at all. The more random
the wiring the better the impedance.

Ah, crosstalk as an impedance controlling technique.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[Steve Wilson]

Tauno Voipio <tauno.voipio@notused.fi.invalid> wrote:

Wire-wrap was pretty normal for the computer backplanes of the
1960's and 1970's. Often the regular bus lines were circuit board
foils and the non-regular lines wire-wrapped on the connector pins.

At Memorex, late 60's, the disk controller backplane was wirewrapped by an
outside firm. It didn't work.

All the unnamed nets were wired together.

 

[John Larkin]

On Wed, 24 Jul 2019 22:25:48 -0400, krw@notreal.com wrote:

On Tue, 23 Jul 2019 20:32:28 -0400, Martin Riddle
martin_ridd@verizon.net> wrote:

On Mon, 22 Jul 2019 12:14:44 -0700, John Larkin
jjlarkin@highland_snip_technology.com> wrote:

On Mon, 22 Jul 2019 21:42:58 +0300, upsidedown@downunder.com wrote:

On Mon, 22 Jul 2019 08:28:38 -0700, John Larkin
jjlarkin@highlandtechnology.com> wrote:

On Mon, 22 Jul 2019 15:18:55 +0000 (UTC),
DecadentLinuxUserNumeroUno@decadence.org wrote:

This would be a good app to have for examining netlist connections

http://apolloguidance.computer/2003100_071/pins

We used to do wire-wrap backplanes and boards. It was horrible.

And to make things even worse, all wire wraps were single color


No, we used colors for manually wrapped things. Not full auto.

Does anybody still use wire-wrap?

I use wire-wrap wire, but not for wire wrapping.

I find that the #30 Kynar wire is great for reworking SMT boards.

I prefer Teflon wire, though I've switched from #30 to #32 wire
(because I can't find smaller). #30 wire is huge compared to 0402s
and QFP leads, for instance.

The beldsol thermal-strip magnet wire is useful, sometimes.

https://www.dropbox.com/s/sxouux4isykh3d9/Beldsol_30.JPG?raw=1

It solders a lot better if you scrape away just a bit of the
insulation first. It does allow daisy-chain connections with one piece
of wire and no stripping.




--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[John Miles, KE5FX]

On Thursday, July 25, 2019 at 12:45:25 PM UTC-7, John Larkin wrote:

It solders a lot better if you scrape away just a bit of the
insulation first. It does allow daisy-chain connections with one piece
of wire and no stripping.

This is particularly good stuff:
https://www.amazon.com/dp/B0082CV1KQ

The enamel melts almost instantly. To solder it, you just pretend the
enamel isn't even there. Soon enough it won't be.

-- john, KE5FX

 

[Martin Riddle]

On Thu, 25 Jul 2019 15:18:30 -0700 (PDT), "John Miles, KE5FX"
<jmiles@gmail.com> wrote:

On Thursday, July 25, 2019 at 12:45:25 PM UTC-7, John Larkin wrote:
It solders a lot better if you scrape away just a bit of the
insulation first. It does allow daisy-chain connections with one piece
of wire and no stripping.

This is particularly good stuff:
https://www.amazon.com/dp/B0082CV1KQ

The enamel melts almost instantly. To solder it, you just pretend the
enamel isn't even there. Soon enough it won't be.

-- john, KE5FX

Theres a ROHS exemption on thin wire, because without lead, the copper
migrates into the solder. Just something to beware of.

Cheers

 

[Steve Wilson]

"John Miles, KE5FX" <jmiles@gmail.com> wrote:

This is particularly good stuff:
https://www.amazon.com/dp/B0082CV1KQ

The enamel melts almost instantly. To solder it, you just pretend the
enamel isn't even there. Soon enough it won't be.

-- john, KE5FX

This is 40 ga. I find such thin wire breaks easily and won't carry much
current.

I'd go for 28 ga. Much more robust.

https://www.amazon.ca/Remington-Industries-28SNSP-Enameled-
Diameter/dp/B0082CUOWC

 

[Steve Wilson]

Steve Wilson <no@spam.com> wrote:

I'd go for 28 ga. Much more robust.

https://www.amazon.ca/Remington-Industries-28SNSP-Enameled-
Diameter/dp/B0082CUOWC

I found out what "sold ER able" means

"soldERable"

Why do people do these things.

 

[Jasen Betts]

On 2019-07-26, Steve Wilson <no@spam.com> wrote:

Steve Wilson <no@spam.com> wrote:

I'd go for 28 ga. Much more robust.

https://www.amazon.ca/Remington-Industries-28SNSP-Enameled-
Diameter/dp/B0082CUOWC

I found out what "sold ER able" means

"soldERable"

Why do people do these things.

spelling checkers, also the vendor doesn't know the product.

--
When I tried casting out nines I made a hash of it.

 

[Phil Hobbs]

On 7/25/19 6:18 PM, John Miles, KE5FX wrote:

On Thursday, July 25, 2019 at 12:45:25 PM UTC-7, John Larkin wrote:
It solders a lot better if you scrape away just a bit of the
insulation first. It does allow daisy-chain connections with one piece
of wire and no stripping.

This is particularly good stuff:
https://www.amazon.com/dp/B0082CV1KQ

The enamel melts almost instantly. To solder it, you just pretend the
enamel isn't even there. Soon enough it won't be.

-- john, KE5FX

About $4 per mile of wire. Not bad!

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Phil Hobbs]

On 7/25/19 3:45 PM, John Larkin wrote:

On Wed, 24 Jul 2019 22:25:48 -0400, krw@notreal.com wrote:

On Tue, 23 Jul 2019 20:32:28 -0400, Martin Riddle
martin_ridd@verizon.net> wrote:

On Mon, 22 Jul 2019 12:14:44 -0700, John Larkin
jjlarkin@highland_snip_technology.com> wrote:

On Mon, 22 Jul 2019 21:42:58 +0300, upsidedown@downunder.com wrote:

On Mon, 22 Jul 2019 08:28:38 -0700, John Larkin
jjlarkin@highlandtechnology.com> wrote:

On Mon, 22 Jul 2019 15:18:55 +0000 (UTC),
DecadentLinuxUserNumeroUno@decadence.org wrote:

This would be a good app to have for examining netlist connections

http://apolloguidance.computer/2003100_071/pins

We used to do wire-wrap backplanes and boards. It was horrible.

And to make things even worse, all wire wraps were single color


No, we used colors for manually wrapped things. Not full auto.

Does anybody still use wire-wrap?

I use wire-wrap wire, but not for wire wrapping.

I find that the #30 Kynar wire is great for reworking SMT boards.

I prefer Teflon wire, though I've switched from #30 to #32 wire
(because I can't find smaller). #30 wire is huge compared to 0402s
and QFP leads, for instance.

The beldsol thermal-strip magnet wire is useful, sometimes.

https://www.dropbox.com/s/sxouux4isykh3d9/Beldsol_30.JPG?raw=1

It solders a lot better if you scrape away just a bit of the
insulation first.

Yup.

It does allow daisy-chain connections with one piece
> of wire and no stripping.

Genuine Belden wire is horrifically overpriced, though--I get the same
stuff very cheap on eBay.

RG-402 semirigid coax used to be fairly cheap too, but a decade or so
back the price about tripled and has stayed high. Belden wants about $8
per foot!

Cheers

Phil Hobbs


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[John Larkin]

On Fri, 26 Jul 2019 08:11:36 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 7/25/19 3:45 PM, John Larkin wrote:
On Wed, 24 Jul 2019 22:25:48 -0400, krw@notreal.com wrote:

On Tue, 23 Jul 2019 20:32:28 -0400, Martin Riddle
martin_ridd@verizon.net> wrote:

On Mon, 22 Jul 2019 12:14:44 -0700, John Larkin
jjlarkin@highland_snip_technology.com> wrote:

On Mon, 22 Jul 2019 21:42:58 +0300, upsidedown@downunder.com wrote:

On Mon, 22 Jul 2019 08:28:38 -0700, John Larkin
jjlarkin@highlandtechnology.com> wrote:

On Mon, 22 Jul 2019 15:18:55 +0000 (UTC),
DecadentLinuxUserNumeroUno@decadence.org wrote:

This would be a good app to have for examining netlist connections

http://apolloguidance.computer/2003100_071/pins

We used to do wire-wrap backplanes and boards. It was horrible.

And to make things even worse, all wire wraps were single color


No, we used colors for manually wrapped things. Not full auto.

Does anybody still use wire-wrap?

I use wire-wrap wire, but not for wire wrapping.

I find that the #30 Kynar wire is great for reworking SMT boards.

I prefer Teflon wire, though I've switched from #30 to #32 wire
(because I can't find smaller). #30 wire is huge compared to 0402s
and QFP leads, for instance.

The beldsol thermal-strip magnet wire is useful, sometimes.

https://www.dropbox.com/s/sxouux4isykh3d9/Beldsol_30.JPG?raw=1

It solders a lot better if you scrape away just a bit of the
insulation first.

Yup.

It does allow daisy-chain connections with one piece
of wire and no stripping.

Genuine Belden wire is horrifically overpriced, though--I get the same
stuff very cheap on eBay.

That's where I got my genuine Beldsol.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote in
news:qheqlr$2dv$1@dont-email.me:

Yup.

It does allow daisy-chain connections with one piece
of wire and no stripping.

Genuine Belden wire is horrifically overpriced, though--I get the
same stuff very cheap on eBay.

RG-402 semirigid coax used to be fairly cheap too, but a decade or
so back the price about tripled and has stayed high. Belden wants
about $8 per foot!

Cheers

Yeah, but they go to like 30GHz now too. What I mean is are they
not a lot more reliable and better constructed now? (I know... not
$8 a foot better)

A lot of the signal pipes on quantum computers are semirigid
matched sma links.

 

On Thu, 25 Jul 2019 09:05:41 -0700, John Larkin
<jjlarkin@highlandtechnology.com> wrote:

On Wed, 24 Jul 2019 22:20:55 -0400, krw@notreal.com wrote:

On Mon, 22 Jul 2019 10:38:57 -0700, John Larkin
jjlarkin@highland_snip_technology.com> wrote:

On Mon, 22 Jul 2019 09:58:57 -0700 (PDT), Lasse Langwadt Christensen
langwadt@fonz.dk> wrote:

mandag den 22. juli 2019 kl. 18.45.04 UTC+2 skrev John Larkin:
On Mon, 22 Jul 2019 09:27:51 -0700 (PDT), Klaus Kragelund
klauskvik@hotmail.com> wrote:

Wirewrap is a stable gas tight connection. I am seriously considering it for a new design

Cost is super cheap, only high investment in robotics

It's terrible for fast stuff, and can be flakey. Are wires still
gas-tight after they break?

It's not cheap! PCBs are cheap.

Optimizing wire-wrap is the "traveling salesman" problem. I've written
programs to re-order wire-wrap lists to approximately minimize total
wire length. Never again!

how is that different from a PCB?

For one thing, wire-wrap doesn't have power pours!

It certainly can. Augat used to sell standardized panels with power
on one side and ground on the other. Some had the corners connected
and others used things that looked like 0.100" bobby pins, soldered
around the WW socket pin to connect to the pour. They worked
exceedingly well. I used them up to about 50MHz.

A PCB can make a tee or plop a via anywhere; it doesn't need a post to
make a junction. That is not the traveling salesman problem, or the
wire-wrap problem, which have fixed nodes.

Which, of course is horrible for speed, which you were just
complaining about.

I control impedances and terminations on a PCB. I can have a 50 ohm
trace that splits into two 100 ohm traces. Wire-wrap can't do that.

Wire-wrap was expensive and barbaric, which is why hardly anyone uses
it any more. It was sorta usable for breadboarding, back when we used
DIP ic's in sockets. I don't miss any of that.

The really good thing nowadays is quick-turn, cheap multilayer PCBs
for prototyping.

After 50 years and a few trillion dollars, I'd hope we'd have learned
a few things.

I recall only being able to make two automatic wraps on a post, so a
node was topologically one long string. A PCB has no such constraints.

There were 3-level pins, as well. Long strings are better, in any
case.

DEC's early PDP-11 boxes used a wire-wrap backplane for the unibus. It
was a slow signal-integrity nightmare. It was shocking that they would
do something so stupid.

IBM used WW for board backplanes, as well. Worked really well, though
they were also printed and multi-layer.

What is the impedance of a wire-wrap wire? How repeatable is it?

100-ohms, with teflon wire, anyway. Not bad at all. The more random
the wiring the better the impedance.

Ah, crosstalk as an impedance controlling technique.

Exactly the opposite. Random wiring reduced crosstalk (few/no
parallel wires) and helped control impedance.