Do people not wire wrap anymore?

[jmelson]

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.

FPGAs are quite different from CPUs.  CPUs do one tiny instructon at a time, everything sequential.  FPGAs and CPLDs do everything in parallel.  VHDL and Verilog may LOOK like computer code, but they are something totally different.  basically, they are a computer-readable schematic.  In fact, at least with Xilinx, you can actually enter a 74xx schematic design and compile it into an FPGA or CPLD device.

The big advantage of these is that you can tinker with experimental changes and view operation in the simulator, without ever having to pull out any wirewrap wires.  If the results are not good, just load the old version back in.

(Yes, you can probably TELL I'm a convert!)

Jon

[RoGeorge]

with Xilinx, you can actually enter a 74xx schematic design and compile it

Enter a schematic was possible in the old Xilinx ISE. The old IDE, Xilinx ISE is still available, but it was frozen, and will not support any current FPGAs, just the old ones.

In their new IDE (new since 2012 or so), Xilinx Vivado, the schematic editor is not present anymore, and AFAIK there were no plans to ever add a schematic editor in Vivado. Did Xilinx added a schematic editor to Vivado?

[NiHaoMike]

In their new IDE (new since 2012 or so), Xilinx Vivado, the schematic editor is not present anymore, and AFAIK there were no plans to ever add a schematic editor in Vivado. Did Xilinx added a schematic editor to Vivado?

Vivado does have a schematic viewer. It even lets you color the individual "wires" as a sort of coloring book for adults. I compiled a miner for my Artix 7 (doesn't make much - about $7 per month) for the fun of it, then an event about a month and a half ago got me to open the design and try to find something to post on Facebook for my friends to see. (They really liked it, BTW.) Then I discovered the "coloring" feature and it went in an unexpected direction... (The design is supposed to help an artist, even if only a little, not become art itself!)

Just one comment from a friend:

Wow! This is so neat and nothing I would’ve ever stumbled upon on my own. Thank you so much for sharing Mike! Your best friend is lucky to have you

[RoGeorge]

The schematic viewer is a completely different thing, and it was always present. We were talking about an editor that enable one to input a circuit description as a graphical schematic diagrams, instead of using text to describe a circuit (like e.g. VHDL or Verilog).

In the old Xilinx ISE it was possible to use graphic symbols, like flip-flops, gates, counters and so on in order to draw the desired circuit. ISE was capable to generate a bitstream starting from schematic drawings. In ISE there are libraries like 7400 series, for those who prefer to design with discrete logic circuits.

Vivado discontinued the schematic input option, and will never add that back.

[woodchips]

Some of my Speedwire AT boards from decades ago.

First two a 68020 version of the Corvus Concept computer.
Three and four a part of a simple sheet metal punch controller I designed, until the WEEE directive decided that 100kg of punch plus 0.5kg of controller was an electronic product so the whole 100kg came under the weight delivered for the payments! Put me out of business.
Five is a combined 68020 with two 56001 DSPs, thought I would continue with image processing when made redundant so made this, never been used!

[RoGeorge]

That's a very clean wire wrap! 

For me, wire wrap sockets were always expensive and hard to find, so even back in the days of the WW glory, I was using wire wrap, but solder the wire instead of wrapping it. I was not even removing the wire insulation, just burned the insulation on the solder pad. This technique of burning the isolation on the pad spares a lot of time with cutting and stripping, yet it was unexpectedly reliable.

I have an entire Z80 computer built with soldered WW, and still works after many decades.



More pics and stories here https://hackaday.io/project/1411-xor-hobby-a-vintage-z80-computer-prototype

Sometimes I still use soldered WW even today, for small prototypes only, but these occasions became less and less frequent.

WW might be still present in very particular cases, but not as a mainstream technique. WW is very expensive, time consuming, not suitable for current IC packaging, it doesn't make sense for SMT, and probably not working at all for high speed buses or high speed differential signals were matching wire lengths and impedances are critical.

I don't think people is still using wire wrap any more.

[daveshah]

Vivado may not have traditional schematic entry, but it certainly has a block design editor that can connect together modules - very useful for dealing with things like AXI buses. I'm sure it has some traditional components too, but they're a bit ugly and it's not really intended for that.

[BBQ]

A few niche products are still manufactured today using wire wrap! Not just old designs, some new too. It seems to last forever done properly.

[jmelson]

with Xilinx, you can actually enter a 74xx schematic design and compile it

Enter a schematic was possible in the old Xilinx ISE. The old IDE, Xilinx ISE is still available, but it was frozen, and will not support any current FPGAs, just the old ones.

In their new IDE (new since 2012 or so), Xilinx Vivado, the schematic editor is not present anymore, and AFAIK there were no plans to ever add a schematic editor in Vivado. Did Xilinx added a schematic editor to Vivado?

Being an old schematic guy, I started with CPLDs and FPGAs using schematics, but quickly realized it was kind of a dead end.  I could put a lot of functionality on one schematic sheet, but I began to see the benefits of an HDL.
So, I'm not sad that schematic -> FPGA has gone away.

Still, on ISE 10 through 14, I'm pretty sure you can still do the schematic thing.  You certainly can do a top-level schematic for the underlying HDL modules (although you don't have to, and I don't.)

Xilinx's ISE 10 through 14 support quite reasonable devices like the 9500XL CPLD family and the Spartan 3A FPGA which are still in production.  These are some of the most affordable parts in the market, too.  If you are not piping serial data streams around at GHz+ speeds, they really do fine, and real mortals can actually solder them to 2-layer boards and have them work.

Jon

Jon

[jmelson]

That's a very clean wire wrap! 

For me, wire wrap sockets were always expensive and hard to find, so even back in the days of the WW glory, I was using wire wrap, but solder the wire instead of wrapping it.

Wow!  A friend of mine built a Data General Nova clone (16-bit mini) with a technique like that.  He had a bunch of wire-wrap-like boards made, but soldered the IC's to pads, and then wired everything together with WWW, but he did strip the ends.  This allowed the boards to pack closer together.

Jon

[RoGeorge]

He had a bunch of wire-wrap-like boards made, but soldered the IC's to pads, and then wired everything together with WWW, but he did strip the ends.

Indeed, with "normal" WW, like the one made in western countries, it was very hard, if not impossible, to make reliable solder joints without stripping. That matte white WW seen in the pic was what we use to have "on the other side" of the Berlin Wall. Not sure where was made that white WW, but I assume somewhere in Eastern Europe, or maybe USSR.

It might have been made in RSR (Socialist Republic of Romania) as well. At that time, any import from western countries was severely limited by the PCR (Romanian Communist Party) if not completely banned, so western WW was like Unobtainium here. To counterbalance the lack of western parts and/or technologies, the Eastern block countries were reinventing the wheel all the time, or simply copy by reverse engineering or industrial espionage. In the particular case of my country, Romania, there was a famous case of a security officer, General Pacepa (the head of Romanian intelligence service), who flee the country during the communist regime. Later, he wrote a book "Red Horizons"
https://www.cia.gov/library/readingroom/docs/CIA-RDP90M00005R001300010017-4.pdf
https://books.google.ro/books/about/Red_Horizons.html?id=zQ7LSucBylAC&redir_esc=y&hl=en
where he described the industrial espionage, including some interesting story about stealing Texas Instruments technology (I think it was about the military 74xx TTL family circuits, but not sure), the plans of a western tank, incredible details about the life of Ceausescu family and other top political figures under the Iron Curtain.

Anyway, back to our eastern European WW, the insulation was very bad when compared to the "normal" western WW. As soon as that matte white insulation was touched with the soldering iron, the insulation burned itself into smoke, yet the solder somehow manage to wet very well the "carbonized" wire, so I used the crappy quality of the insulation as an advantage, in order to avoid stripping and cutting. It was even possible to put a blob of solder in the middle of an unstripped and uncutted wire, which was very handy, especially for memory busses.

[thermistor-guy]

There's just no sense to wire up a bunch of 74xx chips today.

I'm doing just that to make a controller for a bidirectional DC/DC converter. (Actually using 4000 series because that part of the logic runs on 12V.) A FPGA or CPLD would not be able to meet the very low standby/pass through power goal of 1mA or less, plus it would require level translation.

When I was an EE student, one of my classes had a guest lecturer who specialized in industrial process control. He was a big fan of the original 4000 series logic, because of its noise immunity. Running it on 12V or 15 V gave lots of logic level noise margin, plus its slow speed helped it reject fast EMI transients. And it used very little power.

In his applications, the goal was reliability in electrically harsh environments. Most of us were dreaming about how to make computers that ran as fast as possible, but he urged us, in general, to use the slowest logic family that was adequate for the job.

It's interesting to know there are still modern applications for 12V logic.

[tggzzz]

There's just no sense to wire up a bunch of 74xx chips today.

I'm doing just that to make a controller for a bidirectional DC/DC converter. (Actually using 4000 series because that part of the logic runs on 12V.) A FPGA or CPLD would not be able to meet the very low standby/pass through power goal of 1mA or less, plus it would require level translation.

When I was an EE student, one of my classes had a guest lecturer who specialized in industrial process control. He was a big fan of the original 4000 series logic, because of its noise immunity. Running it on 12V or 15 V gave lots of logic level noise margin, plus its slow speed helped it reject fast EMI transients. And it used very little power.

In his applications, the goal was reliability in electrically harsh environments. Most of us were dreaming about how to make computers that ran as fast as possible, but he urged us, in general, to use the slowest logic family that was adequate for the job.

It's interesting to know there are still modern applications for 12V logic.

35 years ago I did a short consultancy study into whether it was worth replacing logic with a micro in a specific application. I concluded that it was not, since the existing logic was extremely reliable and micros would involve all sorts of new hazards specifically including electricity.

That logic was (and probably still is) powered by 2000psi gas.

[NiHaoMike]

It's interesting to know there are still modern applications for 12V logic.

I even managed to condense it down to 3 chips - two doing actual logic and one doing level translation from the 5V microcontroller that generates the PWM signal.

35 years ago I did a short consultancy study into whether it was worth replacing logic with a micro in a specific application. I concluded that it was not, since the existing logic was extremely reliable and micros would involve all sorts of new hazards specifically including electricity.

That logic was (and probably still is) powered by 2000psi gas.

A place where 2000 PSI of high pressure gas is considered less of a hazard than a few volts of electricity must be very strange indeed.

[tggzzz]

It's interesting to know there are still modern applications for 12V logic.

I even managed to condense it down to 3 chips - two doing actual logic and one doing level translation from the 5V microcontroller that generates the PWM signal.

35 years ago I did a short consultancy study into whether it was worth replacing logic with a micro in a specific application. I concluded that it was not, since the existing logic was extremely reliable and micros would involve all sorts of new hazards specifically including electricity.

That logic was (and probably still is) powered by 2000psi gas.

A place where 2000 PSI of high pressure gas is considered less of a hazard than a few volts of electricity must be very strange indeed.

Not really; there are many unmanned offshore oil platform - lots of flammable/explosive gases.

Don't consider how things work, consider how things fail

[jmelson]

A place where 2000 PSI of high pressure gas is considered less of a hazard than a few volts of electricity must be very strange indeed.

Many, many years ago the Moog company (inventors of proportional hydraulic valves) designed an early CNC control.
It used programs punched on wide cloth tape, and the controller was entirely fluidic - compressed air.  The "paper" tape reader looked like something out of a player piano, a plate with many dozens of holes connected to an equal number of little tubes.  The linear encoders on the machine slides were also plates with holes that lined up to holes on a fixed plate in a vernier sort of fashion.  When the holes in the encoder matched the holes in the tape, the axis was on position.  Movement of the axes was done with their proportional valves operating either hydraulic cylinders for short axes or hydraulic motors and leadscrews for the longer ones.

Whew, what a nightmare.  But, the controller was amazingly compact,certainly much smaller than a discrete transistor implementation of the day would have been.

Jon