Making your own wire wrap boards

[MileHigh]

It occurred to me that I don't think I have ever seen a project done around here with wire wrap boards and sockets.  It's actually a very good way to do a project board.  The one "catch" is your chips have to be DIP chips which are getting harder to get.  For certain types of surface mount chips there are "chip carriers" that mount the surface mount chip into a device that gives you a DIP package.

I think of the Akula project where everybody waited for real PCBs.  This is an example of were a wire wrap build would have probably been faster and easier.  Also, with wire wrap, you have infinite flexibility to modify the circuit.

http://en.wikipedia.org/wiki/Wire_wrap
http://makezine.com/2009/07/27/lost-knowledge-wire-wrapping/
http://www.jameco.com/jameco/workshop/techtip/wirewrap.html

[MarkE]

It occurred to me that I don't think I have ever seen a project done around here with wire wrap boards and sockets.  It's actually a very good way to do a project board.  The one "catch" is your chips have to be DIP chips which are getting harder to get.  For certain types of surface mount chips there are "chip carriers" that mount the surface mount chip into a device that gives you a DIP package.

I think of the Akula project where everybody waited for real PCBs.  This is an example of were a wire wrap build would have probably been faster and easier.  Also, with wire wrap, you have infinite flexibility to modify the circuit.

http://en.wikipedia.org/wiki/Wire_wrap
http://makezine.com/2009/07/27/lost-knowledge-wire-wrapping/
http://www.jameco.com/jameco/workshop/techtip/wirewrap.html

Wire wrap's salad days are in the past.  These days you can whip up a 2 layer circuit board and have samples back in 3-4 business days for around $75 w/o solder mask and silkscreen or $95 w/ solder mask and silkscreen.    Or for a bit more you can have a four layer board with proper power and ground planes. 

[TinselKoala]

I've done a few. I have a nice manual wire-wrap tool with a stripper in the handle. I'm almost out of wire, though, since I've been using it for other things (like the variometer coil set of my Aussie Crystal Radio.)

I've also done a few pseudo-surface-mount things like this Akula rep:

[MileHigh]

Where I worked in the 80s they implemented an entire gate array design with discrete TTL chips on a big wire wrap  board.  It must have been about 14" x 14".  Once they debugged it then they committed the design to silicon.  Needless to say, this was about 1986 and I don't think the software simulation tools were available at that time.

It's funny and quaint to hark back to the old days.  You might know about the first microprocessor, the Intel 4004 from 1971.   The physical layout of the individual layers was done by hand.  They had a large room and the engineers did the layout on the floor of the room.  Once all of the planar transistors were done then they took the pictures of the layers, etc.

I had to lower the resolution of the attached image but if you look carefully you may be able to see how it was done by hand with scissors and scotch tape.

[Pirate88179]

In the 70's my Dad purchased 3 Brown & Sharpe automatic (computer controlled) surface grinders.  The cheapest one was $40,000 and the most expensive was upwards of $80,000.  Well, those damn things hardly ever worked and we had to bring in the company repair guy about 30 times.  The B&S policy was that, if you wanted a repair guy, you had to pay for his transport from wherever he might be at that time...LA, FL, TX..wherever.  You also had to pay for a motel room and food.  Good work if you can get it.

One of the guys that came in to repair them showed me the main boards.  They were all wire-wrapped.  He said that they only did this in proto-type machines in the design phase and he had no idea why we were sold machines like this. He stayed for 3 days and finally gave up as he said the schematics did not match the wire wrapped boards at all. B&S gave us so much crap that my Dad hired a cnc engineer that converted all of the machines to digital control with a small box that did a lot more than the original machines did.  We had no problems since then. 

Funny thing is...when B&S did not hear from us for a while, they wanted to send an engineer to our facility to see how we "fixed" their machines.  My Dad told them to get lost, ha ha.

That was my first experience with wire wrapping.

Bill

PS  Those machines were known as "Dial A Size" and my Dad and his company were featured in Brown & Sharpe's advertising because he bought more of those machines than anyone else at that time.  I still have one of the ads.