One of the "small runs" employing wire wrapping was the Apollo Guidance Computer. Each launch requires two of these units, one in the orbiter and one in the lander.

http://en.wikipedia.org/wiki/Apollo_Guidance_Computer

http://en.wikipedia.org/wiki/Wire_wrap

 

Maybe one of the selling points was that you could un-wrap and change the circuit?

I worked as a industrial tech in the early 80's (Australia) on equipment from many different decades and never once saw anything wire wrapped. The oldest stuff was tagstrips and tagboards or rivetboards (soldered), and anything 1960's onwards had PCBs.

I used to see wirewrap in the US magazines but never in commercial equipment from the UK or USA.

 

All the Digital Equipment Corporation (DEC) minicomputers, PDP-8/S, PDP-9 and PDP-15 that I grew up with and cut my teeth on were all wire wrapped.

 

There's an article about the PDP8 in this issue of Elektor.

 

This is great. It's is interesting to hear about electronics in the past.

You guys need to write this down. There is always someone interested in what you write.

When I was just beginning my EE career in the mid-70's the technology for etching printed circuit boards was a rather labor intensive undertaking. This was a time before computers so there were no tools such as are available today for automating the layout process. Everything was done on single sided PCB or double sided PCB. There were no plated through-hole boards at least at the small company that I worked for. There was only Bishop Graphics tape and translucent vellum. The boards were layed out 4X and then reduced to actual size using a copy camera that was around 3 feet by 3 feet by 4 feet that was housed in its own room. When double sided board were designed we used brass eyelets that were pressed into the boards using an arbor press in place of plated through holes.

This company did video equipment designs such as video distribution amplifiers and special effects video generators. They made a lot of use of wire-wrap technology. The equipment was not high-volume production since it was built for each TV station or network customer on an order by order basis.

Looking back on the experience it really got me off to a great start to my career.


hgmjr

 

Yeah, I used to repair PDP8 and PDP11, though I hesitate to use the term. You clean the card edge connectors, debug (in the classic sense of the word, as in removing insects) the wire wrap, and make sure everything is properly seated. I never did really get into the electronics, though I did test the power supplies (never had a bad one).

One of the applications was for a really old pattern generators, the kind that made the lithographic prints for very old ICs. It had a paper tape reader and a magnetic tape reader. We used it for much courser applications, to make the lithographic plates for microelectronics, what the chips mounted on.

Some bright guy just out of college started a small business making PDP11 emulators using 386 computers. He build the interface card that fit in the computer buss. The shop loved the new networking capability (the engineers could now send the program via network), and the hard drive was a pleasant add on too, no more paper tape or reel to reel drive!

Our IT tried to nix the buy though, as it wasn't a 486. Then they said they wouldn't support it. It was interesting having the main manager of the plant explain it wasn't their call in either case. Many IT departments become arrogant over time. Seems generic to the breed.

My current shop has the same problems interestingly enough. The concept of machine controller seems to escape these guys.

 

I remember one local company (long forget the name and long they are gone) who made a line of "dumb" (no CPU) terminals with a CRT display. Think teletype without all the paper. The connection board between cards was all wire wrap. Guess they had no defined bus.

Another company I worked for that was still profitable but didn't fit the "big picture" was wrapped up in '08 or so still running a PDP8 as the controller for their semiconductor tester. I could have scooped it up but passed for all the wrong reasons.