Do people not wire wrap anymore?

[thermistor-guy]

Wire wrapping was another of those products which was 'hyped' without being properly evaluated. Its key problem is that if a connection needs changing then any other wires on top of that connection have to be removed first, and replaced after. Which can soon develop into a domino effect since the wires removed are now too short to be reused, so any wires on top of the other ends also need to be replaced, and so on.

I disagree with all of this.

NASA has workmanship standards for wire-wrap:
https://workmanship.nasa.gov/lib/insp/2%20books/links/sections/301_discrete%20wiring.html

When wire-wrapping, you wrap wires between the same level on the posts, wherever possible. This limits any domino effect to a few wires at most. A second refinement is to wrap the longer connections first, then use the shorter connections (that run at a different angle), to "pin down" the longer wires close to the PCB or substrate surface.

With a little experience, it becomes second nature to do it this way. Done with care, it looks professional and performs well.

[joeqsmith]

Oh, some links !

http://pico-systems.com/stories/1982.html

http://pico-systems.com/stories/1982b.html

There are some larger products that I wire-wrapped! (But, that was quite a while ago!)

Jon

Very nice work! 

This was one of the last things I built using WW.   This box has a 6811 with some DRAM, FPGA and Ethernet controller.   It emulates an old Centronics printer port and sends the data to an printer server over Ethernet.         

https://youtu.be/l0GiC-dw9W8?list=PLZSS2ajxhiQCKHI3sA_DMpjdnIt9NiOb6&t=124

[joeqsmith]

Back in my analog scope days, I made this digitizer on WW.   

[Cubdriver]

Back in the mid-late 80s when I worked for National Semiconductor, we had a nitride coater made by Coyote Systems that had wire-wrapped circuit boards.  It was scary to look in the card cage, but it never gave us any trouble in that area.  (The vacuum and RF sections, on the other hand....)

HP used wire wrapping for the backplane of the 5360A Computing Counter in the early 70s, too.  (All discreet logic chips, around 300 of them all told.  They're all on small circuit boards, but part of the backplane is shown below):



Properly done, like crimping, it's a very reliable system - the sharp edges of the posts dig into the wire surface, foming a gas tight connection that makes for excellent contact.

-Pat

[tggzzz]

Properly done, like crimping, it's a very reliable system - the sharp edges of the posts dig into the wire surface, foming a gas tight connection that makes for excellent contact.

Just so, except that it is 28 gas-tight connections (assuming the coil has 7 turns).

[GerryBags]

Are the 30AWG wires comparable to PCB traces in terms of stay inductance/capacitance?

I notice Jim Williams included a pic of a large wire wrapped backplane in AN47 on high speed prototyping.

[tggzzz]

Are the 30AWG wires comparable to PCB traces in terms of stay inductance/capacitance?

There is more variability due to the varying distances between wires (i.e. crosstalk) and any groundplane.

The pins are 20mm long which means signals will ring with about 0.5ns period; not good with modern jellybean logic!
https://www.edn.com/electronics-blogs/all-aboard-/4438918/What-is-the-ringing-period-on-an-unterminated-line--Rule-of-Thumb--26

[woodchips]

For its era, WW was a perfectly good interconnect method. I used to WW telephone exchanges, millions of connections! Worked reliably, WW is more reliable than soldered joints. As has been mentioned, some simple rules of thumb, wraps at the same level, don't make the interconnect wires too tight, don't take all bus wires the same route etc and worked fine at 80's processor speeds, even video if careful. It was easy enough to unwrap a connection and then re-wrap it, could do it at least once.

But then Vero Speedwire arrived in the early 80's, which is what I have used ever since.

[tggzzz]

But then Vero Speedwire arrived in the early 80's, which is what I have used ever since.

For some reason I never got on with that.

I did like the IDC version of wirewrap. Imagine a 4-layer perfboard with ground/Vcc planes, and every hole populated with a 2-layer IDC connector (i.e. 4 connections)

Very easy to use, very fast, better electrical performance than wirewrap - but hideously expensive for a hobby.

[KL27x]

Vero wrap is missing the whole wrap part. I find wire wrap is still quite useful for making cables out of pin header. Soldering doesn't provide the strain relief. And with the right stripping technique, there's fairly close to no advantage over regular kynar even when soldering.

99% of the wiring in electronics is very low power signals. 30AWG wire is plenty good for a heck of a lot of repairs and mods and prototyping.

Wire wrapping was another of those products which was 'hyped' without being properly evaluated. Its key problem is that if a connection needs changing then any other wires on top of that connection have to be removed first, and replaced after.

Other than for power and ground, most of the time you only need 2, maybe 3 connections per post/node. It's not often an issue for me, in practice. An extra long header pin can handle 4+ connections, easy, and still leave room for connection to a female header or a probe.

I've never used WW, but it seems as though it would be much easier to check lots of points with a 'scope than it is with a bread-boarded circuit. Once there are a few jumper wires dotted around the place it can hard to find somewhere to clip on a probe. Admittedly, this is without the experience necessary to know the best way to arrange common combos of ICs to optimize interconnecting them.

This is completely true, IME. For anything beyond the very simplest of circuits, I still wire wrap nearly 100% of my connections ON a breadboard. I stick rows of extra long pin header into the board, and any breadboard modules I make have the same long pins which stick up and well as down into the board. 30AWG wires pretty much disappear in comparison to any kind of reuseable jumper wires. When I'm done, I rip off all the wires and throw them away. Each pin gives a place for scope probes, and for female pin headers to stick to. Pin headers are wayyyy better 'en breadboards. The breadboard just gives you a place to stick the headers.   

[Red Squirrel]

I've used wirewrap at my job, I work in a telco CO and sometimes have to punch stuff down on the frame.  Most of the blocks are punch down but we have the oddball block that is wirewrap.  They are neat and there's an odd feeling of satisfaction when you use the wire wrap gun and get a nice connection, but punch down is faster both to perform and to remove. 

If I decided to invest in a wirewrap gun at home I would maybe do it for projects just for fun.  Could probably use PC pin headers. Would actually be faster than soldering small wires when doing point to point on perf boards.

[schmitt trigger]

The real WW-killer has been, in my humble opinion, SMT components. Not only are they significantly are smaller, but one can populate both board sides allowing some extremely efficient and compact designs.

And good double sided PWBAs with solder masks and silkscreens have significantly dropped in price.

[jmelson]

I've never used WW, but it seems as though it would be much easier to check lots of points with a 'scope than it is with a bread-boarded circuit. Once there are a few jumper wires dotted around the place it can hard to find somewhere to clip on a probe. Admittedly, this is without the experience necessary to know the best way to arrange common combos of ICs to optimize interconnecting them.

Yes, IBM even had Tektronix make a thing colloquially called an MST clip.  If you knew the part number, you could order these from Tektronix.  It was a thing that fitted over the tip of a Tek probe, and had a contact that would accept a .025" square pin.  It had a gripping "flag" or handle that made it easy to probe a bunch of points on any wirewrap panel, not just IBM mainframes.  (MST was the name of their 370 computer chips "Monolithic Solid Technology".)

Jon

[thermistor-guy]

Wire-wrap is still a useful technique for some situations. I use it mostly for low-frequency test jigs, test adapters, etc. - situations where I need something right now, and once it works, it will get heavy use, so it must be reliable. At the moment I have a situation where there are no PCBs, just a bunch of connectors fastened to thin steel plate.

Connectors with wrire-wrap terminations can be expensive, or simply unavailable. In the case of D-subminiature connectors, I get parts with the straight PCB pin termination, then wrap to the (round) pins and solder. The soldering needs a deft touch, otherwise the kynar insulation can peel back from the heat. You get the hang of it with practice. As noted by another poster, the wrap gives strain relief.

A few times I have run out of links for 0.1 inch headers on evaluation boards, so I wrapped the (square) header posts instead. Worked fine.

[JonM]

But then Vero Speedwire arrived in the early 80's, which is what I have used ever since.

For some reason I never got on with that.

I did like the IDC version of wirewrap. Imagine a 4-layer perfboard with ground/Vcc planes, and every hole populated with a 2-layer IDC connector (i.e. 4 connections)

Very easy to use, very fast, better electrical performance than wirewrap - but hideously expensive for a hobby.

I would call BICC-Vero Speedwire the "IDC version of wirewrap". I used Speedwire to build some boards with mixed ECL - TTL logic and they worked well. I have a few unused Speedwire EuroCards, the associated sockets and tools waiting for the appropriate application.There was also an ISA bus Speedwire prototype board that had most of the bus interface logic as a printed circuit. I just pulled one out to verify that it was ISA and not a later bus.

I still have an OK Industries battery powered wire wrap tool. I doubt it will ever be used again, but my manual ww tools might be.

[thermistor-guy]

The real WW-killer has been, in my humble opinion, SMT components. Not only are they significantly are smaller, but one can populate both board sides allowing some extremely efficient and compact designs.

And good double sided PWBAs with solder masks and silkscreens have significantly dropped in price.

I would add PC performance and PCB layout s/w to that list.

The layout s/w is now much cheaper, often free, more capable, and available for PCs. PC performance, and especially graphics card performance, have just exploded over the years. That's partly thanks to the high-performance needs of gaming and the size of the gaming market.

I can remember the days of auto-router s/w, with rip-up and retry, just crawling along on an i386 PC, on an overnight run. Gone are the days when you needed an expensive Sun workstation or similar to do any decent layout work.

[joeqsmith]

Some more of my old wire wrapped boards I was using to play around with my own CPU designs.   In the early 80's, I was running a couple of MHz on wire wrap and impressed with my self.  The large board, built in the 90s was using a 100MHz clock.   Fast forward another 20 some years, I am amazed how far we have come.               

https://youtu.be/C8txvmXUIJQ?t=493

Second video showing the larger board in operation. 

https://youtu.be/5OUfx2F43ek

[tggzzz]

But then Vero Speedwire arrived in the early 80's, which is what I have used ever since.

For some reason I never got on with that.

I did like the IDC version of wirewrap. Imagine a 4-layer perfboard with ground/Vcc planes, and every hole populated with a 2-layer IDC connector (i.e. 4 connections)

Very easy to use, very fast, better electrical performance than wirewrap - but hideously expensive for a hobby.

I would call BICC-Vero Speedwire the "IDC version of wirewrap". I used Speedwire to build some boards with mixed ECL - TTL logic and they worked well. I have a few unused Speedwire EuroCards, the associated sockets and tools waiting for the appropriate application.There was also an ISA bus Speedwire prototype board that had most of the bus interface logic as a printed circuit. I just pulled one out to verify that it was ISA and not a later bus.

I still have an OK Industries battery powered wire wrap tool. I doubt it will ever be used again, but my manual ww tools might be.

Same ecological niche, same performance, but I'm referring to a pukka IDC connector on each pin in the matrix.

I occasionally use my manual wirewrap tool, mainly for stripping the 30AWG kynar wirewrap wire.

[@rt]

A lady in a FB group I’m in has made several ISA cards recently, all wire wrap.
I’ve seen some of her older projects, and the only difference is they have seemingly become much neater.
Something I noticed with her very last ISA cards she posted pics of.

I bought the cheap China tool, but still waiting for the right project.
I wire wrapped a core memory address matrix, but that was the only wire wrap in the  project, and still the only WW I’ve ever done.

[JonM]

For the record, wire wrapped and SpeedWire ISA boards from the mid 1980s. SpeedWire was so nice. You could get fully populated (with sockets) boards or just place sockets where you needed them.

Yes, I probably should have used RG-174 or other coax on that SpeedWire version. I don't remember exactly what I used this board for, I think that it was a timing sequencer (9513 was my favorite timer counter chip back in the day, I still have the data book and some chips, 8255 is a GPIO chip).

Both boards were stored in the same storage bin. Some wire wrap pins are smashed together. The Speedwire board appears to be damage free.

[Kleinstein]

With now much better tools to make a PCB and reasonably cheap services to make the boards, there is less need for wire wrapping.

Also more and more parts are SMT only - so they would need extra adapter boards to do wire wrap.
Part size is here less the point - more like availability.

In the early days (1960s) they even used a kind of wire wrapping in small series commercial products. I remember taking apart an old calculator with a back-plane wiring made in a kind of solder-less wire wrapping. Sorry no pictures for that tear-down  . Dave would have loved a 4 banger with nixi tubes and all discrete).
AFAIR the Cray 2 still used that kind of odd technique - fault finding must have been a night mare with a thick layer of all white and blue  (all the same) cables in a chaotic mesh.

[tggzzz]

Yes, I probably should have used RG-174 or other coax on that SpeedWire version.

It looks about 10cm long. Twisted pair with IIRC 1 twist/cm is a good 100ohms transmission line for digital signals. I doubt there would have been significant improvement in signal integrity with that logic's transition times.

[schmitt trigger]

AFAIR the Cray 2 still used that kind of odd technique - fault finding must have been a night mare with a thick layer of all white and blue  (all the same) cables in a chaotic mesh.

I once briefly saw a Control Data's Cyber 70 (I believe) mainframe. You are correct, the amount of wiring was beyond belief.

I had the opportunity to see it because an acquaintance was IT director at this company and invited me to see it during some down time. To improve the clock and bus speeds, Control Data engineers were contracted to refurbish the main processing unit cabinet. The main effort was to re-place and re-route all the wiring.

[Beamin]

And instead of building logic circuits out of individual 74xx chips, you can write some Verilog or VHDL and load it onto a FPGA.

Maybe you can but I can't.  I find the code writing part tedious and frustrating. Why write a line of code in software for say something like debounce when you can add a whole bunch of extra parts.

[duak]

When I was looking for my first job in the 70's, I showed my M6800 micro with 8K of static memory (sixty four 16 pin DIPs) all manually wire wrapped on perfboard.  I made my own bus bars of double sided PCB material for power distribution and made power and ground to the chips a mesh.  I'd like to think it helped.  I gave that computer away but I still have another one based on the 8085 but using newer chips.  Wire wrap was no fun, but it sure beat the alternatives.

We used  wire wrap for prototypes and low volume boards because in the days before computerized PCB layout, because wire wrappers were cheaper than PCB designers.  We could give them a D-sized drawing and usually get a board back in a couple of days, QC'd and everything.  I don't believe I ever found a mistake, something I couldn't always say for myself.  I remember writing a netlist program for backplanes using 8080/Z80 assembler on CP/M.  One computer it ran on had a noisy switching power supply that whistled a neat melody while the line printer banged out the percussion on 11 X 17 fanfold paper.  It beat having to send off and wait for a service center to run the previous Fortran program.

I've got one wire wrap board that's designed for ECL.  It has two level pins and spots for terminators just about everywhere.  I've seen boards using twisted pair for point to point connections.

I understand that Garner Denver developed automated wire wrapping machines in the 60's that were used until the 80's.  I suppose they were programmed by paper tape.

I started using Speedwire in the mid 80's and still have a bunch of new and used cards sitting around somewhere - just in case I decide to build something to use all the DIP chips I saved.  Even then, the boards themselves were generally worth more than the chips they were carrying.

Cheers,